WorldWideScience

Sample records for two-frequency he-ne laser

  1. Chaotic He-Ne laser

    Science.gov (United States)

    Kuusela, Tom A.

    2017-09-01

    A He-Ne laser is an example of a class A laser, which can be described by a single nonlinear differential equation of the complex electric field. This laser system has only one degree of freedom and is thus inherently stable. A He-Ne laser can be driven to the chaotic condition when a large fraction of the output beam is injected back to the laser. In practice, this can be done simply by adding an external mirror. In this situation, the laser system has infinite degrees of freedom and therefore it can have a chaotic attractor. We show the fundamental laser equations and perform elementary stability analysis. In experiments, the laser intensity variations are measured by a simple photodiode circuit. The laser output intensity time series is studied using nonlinear analysis tools which can be found freely on the internet. The results show that the laser system with feedback has an attractor of a reasonably high dimension and that the maximal Lyapunov exponent is positive, which is clear evidence of chaotic behaviour. The experimental setup and analysis steps are so simple that the studies can even be implemented in the undergraduate physics laboratory.

  2. Discharge modulation noise in He---Ne laser radiation

    NARCIS (Netherlands)

    Bolwijn, P.T.

    1967-01-01

    Discharge modulation noise in He---Ne laser radiation is considered theoretically, including explicitly the laser oscillator properties. Experiments reported previously by us and other authors are in agreement with our analysis.

  3. HeNe双频激光器频差的激光内雕赋值法%Laser-micro-engraving metho d to mo dify frequency difference of two-frequency HeNe lasers

    Institute of Scientific and Technical Information of China (English)

    朱守深; 张书练; 刘维新; 牛海莎

    2014-01-01

    在精密测量领域, HeNe激光器是制造激光干涉仪的首选.但能够产生中频差4-40 MHz的双折射-塞曼双频HeNe激光器的频差是随机的,小到几百kHz,大到十几MHz.为了让频差能够满足制作双频激光干涉仪的要求,曾出现过弹性加力法、钻孔应力调节法等调整和频差赋值的方法.但这些方法在实际应用中都不是很理想.采用激光内雕法赋值频差,通过在激光器的平面输出镜内部雕刻出不同图案,使平面镜内部产生满足要求的相位延迟,达到为频差赋值的目的.激光内雕法有很多优点:不损害激光器,美观;功率损失小,出光强度可接近原始光强度;可反复赋值,频差在0-60 MHz范围内可调整;频差的稳定性好,采用稳频措施后频差的波动范围小于每小时10 kHz.%In the field of precision measurement, HeNe laser is the first choice for fabricating laser interferometer. But the frequency difference of Birefringence-Zeeman dual-frequency HeNe laser, which can produce a medium frequency difference of 4-40 MHz, is randomly from as small as hundreds of kHz to as large as a dozen of MHz. To meet the production requirements for frequency difference of dual-frequency laser interferometer, there are some methods such as elastic strength and hole-drilling stress adjustment. But in the practical application, these methods are not very satisfactory. Laser-micro-engraving method assigns frequency difference by engraving a pattern in the plane mirror, and causes the phase retardation to achieve the purpose of frequency difference assignment. Laser engraving technique has many advantages: harmless to the laser, beauty, low power loss. The output power is close to the original light intensity. The frequency difference can be repeatedly adjusted and is stable. By frequency stabilization, the frequency difference fluctuates in a range of less than 10 kHz per hour.

  4. HeNe-laser light scattering by human dental enamel

    NARCIS (Netherlands)

    Zijp, [No Value; tenBosch, JJ; Groenhuis, RAJ

    1995-01-01

    Knowledge of the optical properties of tooth enamel and an understanding of the origin of these properties are necessary for the development of new optical methods for caries diagnosis and the measurement of tooth color. We measured the scattering intensity functions for HeNe-laser light of 80- to 1

  5. A birefringent cavity He-Ne laser and optical feedback

    Institute of Scientific and Technical Information of China (English)

    Liu Gang; Zhang Shu-Lian; Li Yan; Zhu Jun

    2004-01-01

    Strong modes competition makes only one of o-light and e-light oscillate in a birefringent dual-frequency laser when the angle between the crystalline axis and the laser beam is nearly zero. When the oscillated mode is in a different part of the gain curve, the detected intensity curves of o-light and e-light are quite different in the existence of optical feedback. The curves are divided into five cases. Three cases of the experimental results can be used for direction discrimination. The polarization characteristics of the birefringent cavity He-Ne laser are also discussed without optical feedback.

  6. Treatment of Chronic Diarrhea with Point-irradiation of He-Ne Laser in 50 Cases

    Institute of Scientific and Technical Information of China (English)

    WU Tong-fa; SHI Bing-pei

    2003-01-01

    To treat 50 cases of chronic diarrhea by laser point-radiation on Shenque (CV 8 ), Tianshu (ST25), Zusanli (ST 36) and Point Anti-diarrhea with low power He-Ne laser. The total effective rate was 96%.

  7. Experimental study on He- Ne laser irradiation to inhibit scar fibroblast growth in culture

    Institute of Scientific and Technical Information of China (English)

    舒彬; 吴宗耀; 郝林林; 曾登芬; 冯光锐; 林永辉

    2002-01-01

    To explore the inhibitory effect of He-Ne laser irradiation on fibroblast growth of hypertrophic scars in culture. Methods: He-Ne laser with wavelength of 632.8 nm,power density of 50 mW/cm2 and doses of 3 J/cm2,30 J/cm2, 90 J/cm2 and 180 J/cm2 was used to irradiate human scar fibroblasts in culture 1, 3 and 5 times respectively, and then the cell count and cell cycle analysis were done. Results: Repeated irradiation with He-Ne laser at dose of 180 J/cm2 three and five times led to an evident decrease in total cell number compared with that of the control group and there was a significant difference ( P <0.05). The cell cycle analysis showed after three and five times of irradiation with 180 J/cm2 He-Ne laser the cell number in S-phase decreased from 51% to 20% and 14% respectively, the cell number in G0/G1 phase increased from 28% to 55% and 60% respectively, and the cell percentage in Sub-G1 phase was 6.7% and 9.8% respectively. Conclusions: Repeated irradiation with 180 J/cm2 He-Ne laser can inhibit scar fibroblasts growth in culture.It may be that He-Ne laser irradiation causes cell stagnation in G0/G1 phase and apoptosis.

  8. A preliminary physiological and biochemical study on He-Ne laser mutation breeding of Erigeron breviscapus

    Science.gov (United States)

    Gao, Bo; Zhang, Canbang; Li, He; Lin, Lifei; Zhang, Rui; Zhou, Tengfei; Tian, Jiajin; Zhang, Jucheng

    2008-12-01

    Erigeron Breviscapus is known as a natural plant medicinal material with special clinical effect. In this work, the seeds of Erigeron Breviscapus were irradiated by He-Ne laser (632.8nm, 6mw) with different doses. Plant physiology and biochemistry index such as total soluble sugar and chlorophyll content were analyzed one month after germination to study the He-Ne laser effect to the Erigeron Breviscapus seeds. This work may provide the experimental basis for good growth vigor and high yield genetic character screening of Erigeron Breviscapus treated by laser mutation breeding.

  9. Effects of He-Ne laser irradiation on red blood cells in vitro

    Science.gov (United States)

    Ghadage, Vijay H.; Kulkarni, Gauri R.

    2011-03-01

    Laser radiation has many applications in biomedical field, such as wound healing, tissue repairing, heating and ablation processes. Intravenous low power laser radiation is used clinically for skin and vascular disorders. Laser radiation improves microcirculation and modulates the rheological properties of blood. FTIR (Fourier Transform Infra Red Spectra) is used to see the structural changes in erythrocyte membrane. In the present work He Ne laser (λ= 632nm, power=2mW) is used to irradiate human Red blood cells. Red blood cells are separated from human whole blood using centrifugation method (time=10 min., temperature=15°C and RPM=3000) and then exposed to HeNe laser radiation. Laser exposure time is varied from 10 min. to 40min for Red blood cells. Absorption spectrum, FTIR and fluorescence spectra of RBC are compared before and after HeNe laser irradiation. The absorption spectrum of RBC after exposure to HeNe laser shows a significant decrease in absorbance. The FTIR spectrum of non irradiated RBC clearly show the peaks due to O-H (free group), C=O (amide I group), N=O (nitro group), C-O (anhydride group) and C-H (aromatic group). Laser radiation changes in transmittance in FTIR spectra related to C=O group and percentage of transmittance increases for O-H, C=C, N=O, C-O and C-H group.

  10. Electrophysiological effect of HeNe laser on normal and injured sciatic nerve in the rat.

    Science.gov (United States)

    Rochkind, S; Nissan, M; Razon, N; Schwartz, M; Bartal, A

    1986-01-01

    The effect of low energy CW HeNe laser irradiation on normal and dissected nerves in the rat was examined. The methods are described. Results are compared to the laser effect on other living tissues. HeNe irradiation was found to increase significantly the action potentials of the nerves. It was found to be a long-lasting effect, keeping an increase in the nerves action potential for more than eight months after irradiation has been stopped. A possible explanation for the way the irradiation acts on the nerve is suggested.

  11. An in-vivo experimental evaluation of He-Ne laser photostimulation in healing Achilles tendons.

    Science.gov (United States)

    Elwakil, Tarek F

    2007-03-01

    There is no method of treatment that has been proven to accelerate the rate of tendon healing or to improve the quality of the regenerating tendon. Low level laser photostimulation has gained a considerable attention for enhancing tissue repair in a wide spectrum of applications. However, there is controversy regarding the effectiveness of laser photostimulation for improvement of the healing process of surgically repaired tendons. Accordingly, the present study was conducted to evaluate the role of helium-neon (He-Ne) laser photostimulation on the process of healing of surgically repaired Achilles tendons. Thirty unilateral Achilles tendons of 30 Raex rabbits were transected and immediately repaired. Operated Achilles tendons were randomly divided into two equal groups. Tendons at group A were subjected to He-Ne laser (632.8 nm) photostimulation, while tendons at group B served as a control group. Two weeks later, the repaired Achilles tendons were histopathologically and biomechanically evaluated. The histopathological findings suggest the favorable qualitative pattern of the newly synthesized collagen of the regenerating tendons after He-Ne laser photostimulation. The biomechanical results support the same favorable findings from the functional point of view as denoted by the better biomechanical properties of the regenerating tendons after He-Ne laser photostimulation with statistical significance (p repair of ruptured and injured tendons for a better functional outcome. It could be applied safely and effectively in humans, especially with respect to the proposed long-term clinical outcome.

  12. The effect of He-Ne laser (632.8 nm) and Solcoseryl in vitro.

    Science.gov (United States)

    al-Watban, F A; Andres, B L

    2001-01-01

    He-Ne laser (632.8 nm) and Solcoseryl (SS), a non-protein calf haemodialysate, were used in the enhancement of wound healing. Nonetheless, a study on the use of He-Ne laser with SS has not been done. The purpose of this study is to determine the effect of He-Ne laser biostimulation in combination with SS on Chinese hamster ovary (CHO) and human skin fibroblast (HSF). A dose response for the cloning efficiency (CE) of CHO and HSF cells in 5% fetal bovine serum in minimum essential medium (FBS-MEM) with 6-125 micrograms/ml SS and He-Ne laser using an optimum power density of 1.25 mW/cm2 and cumulative doses (CD) of 60-600 mJ/cm2 given for three consecutive days, were done. The combined effects of He-Ne laser 180 mJ/cm2 with 6 and 12 micrograms/ml SS were determined. Quadruplicate cultures were done. Student t-test was used to determine differences of treatment groups from controls. CHO and HSF CE were increased using 180 mJ/cm2 laser by 13.1% +/- 4.5% (p < 0.0025) and 39.1% +/- 7.9% (p < 0.0005); SS 6 micrograms/ml by 14.4% +/- 8.7% (p = 0.01) and 20.7% +/- 10.9% (p = 0.01); SS 12 micrograms/ml by 17.7% +/- 6.3% (p = 0.001) and 23.9% +/- 5.6% (p < 0.0025); laser + SS 6 micrograms/ml by 15.1% +/- 8.8% (p < 0.01) and 60.9% +/- 9.4% (p < 0.0001); laser + SS 12 micrograms/ml by 23.0% +/- 1.5% (p < 0.0001) and 70.7% +/- 11.4% (p < 0.0001), respectively. Additional significant increases in CE were observed on CHO using laser + SS 12 micrograms/ml by 8.6% +/- 1.3% (p < 0.025) and on HSF using laser + SS 6 micrograms/ml and laser + SS 12 micrograms/ml by 15.6% +/- 6.8% (p < 0.025) and 22.7% +/- 10.6% (p = 0.01), respectively, when compared to the effect of 180 mJ/cm2 laser. Results suggest that further stimulation can be achieved by using He-Ne laser with SS. This could be exploited as a new treatment modality.

  13. Effects of He-Ne laser irradiation on chronic atrophic gastritis in rats

    Institute of Scientific and Technical Information of China (English)

    Xue-Hui Shao; Yue-Ping Yang; Jie Dai; Jing-Fang Wu; Ai-Hua Bo

    2005-01-01

    AIM: To study the effects of He-Ne laser irradiation on experimental chronic atrophic gastritis (CAG) in rats.METHODS: Sixty-three male adult Wistar rats were randomly divided into five groups including normal control group, model control group and three different dosages He-Ne laser groups. The chronic atrophic gastritis (CAG)model in rats was made by pouring medicine which was a kind of mixed liquor including 2% sodium salicylate and 30% alcohol down the throat for 8 wk to stimulate rat gastric mucosa, combining with irregular fasting and compulsive sporting as pathogenic factors; 3.36, 4.80, and 6.24J/cm2doses of He-Ne laser were used, respectively for three different treatment groups, once a day for 20 d. The pH value of diluted gastric acid was determined by acidimeter,the histopathological changes such as the inflammatory degrees in gastric mucosa, the morphology and structure of parietal cells were observed, and the thickness of mucosa was measured by micrometer under optical microscope.RESULTS: In model control group, the secretion of gastric acid was little, pathologic morphological changes in gastric mucosa such as thinner mucous, atrophic glands, notable inflammatory infiltration were found. After 3.36 J/cm2 dose of He-Ne laser treatment for 20 d, the secretion of gastric acid was increased (P<0.05), the thickness of gastric mucosa was significantly thicker than that in model control group (P<0.01), the gastric mucosal inflammation cells were decreased (P<0.05). Morphology, structure and volume of the parietal cells all recuperated or were closed to normal.CONCLUSION: 3.36J/cm2 dose of He-Ne laser has a significant effect on CAG in rats.

  14. Frequency stabilization of internal-mirror He-Ne lasers by air cooling.

    Science.gov (United States)

    Qian, Jin; Liu, Zhongyou; Shi, Chunying; Liu, Xiuying; Wang, Jianbo; Yin, Cong; Cai, Shan

    2012-09-01

    Instead of the traditional heating method, the cavity length of an internal-mirror He-Ne laser is controlled by air cooling which is implemented by a mini cooling fan. The responsive property of the cooling fan and the thermal expansion of the internal-mirror laser tube are investigated. According to these investigations, a controlling system is designed to drive the cooling fan controlling the cavity length of the laser. Then the frequency is stabilized by comparing the light intensities of two operating longitudinal modes. The results of beating with an iodine stabilized He-Ne laser show that a relative uncertainty (Δf/f-) of 4.3×10(-9) in 5 months, a frequency fluctuation of <1.4 MHz, and an Allan deviation of 6×10(-11) (τ=10,000 s) in 20 h are obtained.

  15. Design and study of the intravascular He-Ne laser irradiation therapeutic apparatus

    Science.gov (United States)

    Mao, Haitao; Li, Fangzheng; Wang, Qingguo; Dong, Xingfa; Duan, Qingjie

    1996-09-01

    When the low level He-Ne laser irradiation on both extracorporeally and intracorporeally circulatory blood, it has following useful stimulating functions for the living things: reduce the content of blood plasma middle-molecule substances, increase serum superoxide dismutase, improve hemorheological properties, raise immunity function of organism, etc. We developed the intravascular low level He- Ne irradiation therapeutic apparatus. A He-Ne laser beam of 632.8nm is coupled into 50/125 micrometers optical fiber with the aid of the free lens coupler, after that it entered into the laser pun through the fiber optic connector. The attenuate coefficient of the lens coupler can adjust continuously, so as to choose continuously the output power of the laser pin from 0 to 5 mW. In the pipe of the laser pin there is a large core fiber of 150/190 micrometers, they are stuck to each other. The diameter of the laser pin is less than 0.4 mm, thus it may get into infusion pin of 7, not used with intravenous casing pipe pin. Because it is adopted that the low priced fiber-optic connector, the laser pin can be used only once.

  16. Tuning Characteristics of Frequency Difference for Zeeman-Birefringence He-Ne Dual Frequency Laser

    Institute of Scientific and Technical Information of China (English)

    肖岩; 张书练; 李岩; 朱钧

    2003-01-01

    Characteristics of frequency difference tuning of Zeeman-birefringence He-Ne dual frequency lasers (ZBDFLs) are explored. We design an automatic system of tuning cavity and power detection, which can tune the laser cavity and record the tuning curves of light power and frequency difference simultaneously. A synthetic phenomenon by Zeeman effect, mode pulling effect and birefringence effect is verified to exist in ZBDFLs. By analysing the tuning behaviour, this synthetic phenomenon is discovered and qualitatively explained for the first time.

  17. [Observation on therapeutic effect of acupuncture combined with He-Ne laser radiation on facial paralysis].

    Science.gov (United States)

    Hou, Yan-li; Li, Zhi-Chao; Ouyang, Qi; Li, Xue; Li, Hua; Zhao, Min

    2008-04-01

    To compare therapeutic effects of acupuncture combined with He-Ne laser radiation and western medicine on facial paralysis. Ninety-seven cases were randomly divided into an acupuncture with laser group (n=55) and a medication group (n=42). The acupuncture with laser group were treated by acupuncture at main points, Dicang (ST 4), Jiache (ST 6), Sibai (ST 2), Qianzheng, Xiaguan (ST 7), Yingxiang (LI 20), Yangbai (GB 14), Yuyao (EX-HN 4), Yifeng (TE 17), Hegu (LI 4), in combination with He-Ne laser radiation; the medication group were treated with routine western medicine including intravenous dripping of low molecular dextran, compound Danshen and ATP injections, intramuscular injection of VitB1 and VitB12 , and oral administration of oryzanol and prednisone. Seven days constituted one course. After two courses their therapeutic effects were observed. The cured rate was 81.8% in the acupuncture with laser group and 45.20% in the medication group with a significant difference between the two groups(Pacupuncture combined with He-Ne laser radiation on facial paralysis is better than that of routine medication.

  18. Frequency stabilization of internal-mirror He-Ne lasers by air cooling

    Science.gov (United States)

    Qian, Jin; Liu, Zhongyou; Shi, Chunying; Liu, Xiuying; Wang, Jianbo; Yin, Cong; Cai, Shan

    2013-01-01

    Instead of traditional heating method, the cavity length of an internal-mirror He-Ne laser is controlled by air cooling which is generated by a mini cooling fan. A PID servo controlling system is designed to drive the cooling fan tuning the frequency of the laser. The frequency is stabilized by balancing the power of two operating longitudinal modes. Beating with an iodine stabilized He-Ne laser, a relative uncertainty(Δf / ̅f ) of 4.3×10-9 in 5 months, a frequency fluctuation of less than 2.6 MHz and an Allan deviation of 3×10-11 (τ=100 s) in 75 h are obtained.

  19. Biostimulation Effect For Rheumatoid Arthritis By Low Power He-Ne Laser

    Science.gov (United States)

    Oyamada, Yoshinori

    1989-09-01

    We have studied the effectiveness of He-Ne laser (8.5mW) in treatment of rheuma-toid arthritis of totally 77 cases. Placebo irradiation was applied to 32 patients, and He-Ne laser to 45 cases. The length of irradiation was 15 minutes per each treatment. During the experiment period, the assessment to tenderness, pain on motion, circumference, range of motion, grip strength, duration of morning-stiffness, hydrops, and ESR was performed. Thermograph and other laboratory tests were also assessed. The general assessment by the doctors showed significant clinical diffe-rence (P<0.01) in the intergroup comparison. In the assessment of the patients' personal impression, significant improvement was recorded too (P<0.01).

  20. He-Ne Laser Auricular Irradiation Plus Body Acupuncture for Treatment of Acne Vulgaris in 36 Cases

    Institute of Scientific and Technical Information of China (English)

    Sun Lihong

    2006-01-01

    In order to observe the therapeutic effects of He-Ne laser auricular irradiation plus body acupuncture for acne vulgaris, 68 cases of acne vulgaris were randomly divided into a treatment group of 36 cases treated with He-Ne laser auricular irradiation plus body acupuncture, and a control group of 32 cases treated with body acupuncture only. The results showed that the cure rate was 77.8% in the treatment group and 46.9% in the control group (P<0.05), indicating that He-Ne laser auricular irradiation plus body acupuncture may exhibit better effects for acne vulgaris.

  1. Two-color CO{sub 2}/HeNe laser interferometer for C-2 experiment

    Energy Technology Data Exchange (ETDEWEB)

    Gornostaeva, O.; Deng, B. H.; Garate, E.; Gota, H.; Kinley, J.; Schroeder, J.; Tuszewski, M. [Tri Alpha Energy, Inc., P.O. Box 7010, Rancho Santa Margarita, California 92688 (United States)

    2010-10-15

    A six-channel two-color interferometer has been developed for plasma electron density measurements in the C-2 field reversed configuration experiment. A CO{sub 2} laser is utilized as the main probe beams, while copropagating visible HeNe laser beams are mainly sensitive to vibration. Density measurements in C-2 plasmas have shown that this is a reliable turn-key system. The maximum residual phase noise after vibration compensation is less than {+-}5 deg., corresponding to a line integral density of 3x10{sup 18} m{sup -2}. The time resolution for routine operation is 2 {mu}s.

  2. ABO System Dependence Of Erythrocyte Crenation By Low Power He-Ne Laser Radiation

    Science.gov (United States)

    Rasia, Rodolfo J.; Martinelli, Cristina; Valverde de Rasia, Juana R.

    1982-12-01

    Samples of erythrocytes of different ABO groups, diluted in normal saline, were irradiated with high concentrated low power He-Ne Laser beam during 30 minutes. By microscopic observations made every 5 minutes the crenation time history of the irradiated red cells were determined. Assuming the crenation to have two sequential steps, experimental data of the rate constants for each of two steps of each blood sample were calculated. All these parameters and crenation-time history curves appear different and characteristic for each group of ABO-System. Further work to verify detected sensibility changes in inmunohematological reactions with Laser treated red blood cells is under progress.

  3. Two-color CO2/HeNe laser interferometer for C-2 experiment.

    Science.gov (United States)

    Gornostaeva, O; Deng, B H; Garate, E; Gota, H; Kinley, J; Schroeder, J; Tuszewski, M

    2010-10-01

    A six-channel two-color interferometer has been developed for plasma electron density measurements in the C-2 field reversed configuration experiment. A CO(2) laser is utilized as the main probe beams, while copropagating visible HeNe laser beams are mainly sensitive to vibration. Density measurements in C-2 plasmas have shown that this is a reliable turn-key system. The maximum residual phase noise after vibration compensation is less than ±5°, corresponding to a line integral density of 3×10(18) m(-2). The time resolution for routine operation is 2 μs.

  4. Response of peripheral nerve to He-Ne laser: experimental studies.

    Science.gov (United States)

    Rochkind, S; Nissan, M; Barr-Nea, L; Razon, N; Schwartz, M; Bartal, A

    1987-01-01

    Low-energy He-Ne laser irradiation (LELI) was found to affect the electric activity and morphology in both intact and severely injured peripheral nerves in rats. Action potential (AP) in the healthy nerve increased by 33% following a single transcutaneous irradiation. Similar irradiation in crushed nerves caused AP to increase significantly over the AP of nonirradiated crushed nerve. Morphological observations revealed that a laser-irradiated injured nerve had diminished scar tissue as compared to an injured but not an irradiated nerve.

  5. HeNe laser irradiation delivered transcutaneously: its effect on the sciatic nerve of rats.

    Science.gov (United States)

    Nissan, M; Rochkind, S; Razon, N; Bartal, A

    1986-01-01

    For our study of the effect of low energy laser irradiation (LELI) on living tissue we used HeNe laser on rats. The exponential absorption was reaffirmed in the living tissues overlying the sciatic nerve. An optimal range of energy between 3.5 and 7 J--associated with energy concentration of 4-10 J/cm2 delivered transcutaneously--was found to cause a significant increase in action potential in the sciatic nerve. The effect lasted for more than 8 months after the irradiation session.

  6. Effect of Microwave and He-Ne Laser on Enzyme Activity and Biophoton Emission of Isatis indigotica Fort

    Institute of Scientific and Technical Information of China (English)

    Yi-Ping CHEN; Yong-Jun LIU; Xun-Ling WANG; Zhao-Yu REN; Ming YUE

    2005-01-01

    The seed embryos of Isatis indigotica Fort were exposed to He-Ne laser (5.23 mW/mm2, radiated for 5 min) and microwave (1.26 mW/mm2, radiated for 8 s) irradiation to determine the effects of microwave and He-Ne laser pretreatment on enzyme activities, and biophoton emission of cotyledon. Then: (i) changes in the activities of enzymes in I. indigotica cotyledon (such as amylase, transaminase, and proteinase) were measured to investigate the effects of He-Ne laser and microwave pretreatment; and (ii) biophoton emission was measured to determine the speed of cell division and metabolism. Results from these experiments indicated that: (i) the activities of amylase, transaminase, and proteinase of the cotyledon pretreated by HeNe laser and microwave were significantly increased; and (ii) the intensity of biophoton emission was enhanced significantly by He-Ne laser and microwave irradiation. These changes suggest that He-Ne laser and microwave pretreatment can improve the inner energy of seeds, lead to an enhancement of cotyledon enzymes, and speed up the metabolism of the cell, resulting in significantly increased biophoton emission.Moreover, the mechanism of action of the effects of laser and microwave radiation on the microcalorimetric parameters, enzyme activities, and biophoton emission of seeds is discussed on the basis of the results obtained.

  7. Effects of He-Ne laser irradiation on the storage of turkey semen

    Directory of Open Access Journals (Sweden)

    S. Passarella

    2011-03-01

    Full Text Available Maintenance or improvement of sperm quality during storage could prevent the loss of fertilizing capacity associated with stored turkey semen. Therefore the optimization of stored turkey semen could be useful to breeder industry since the commercial production of this bird relies almost entirely on artificial insemination. Previous research have shown that He-Ne laser irradiation in mammalian sperm increased the motility (Stato, 1986, decreased the mortality, promoted the acrosome reaction, which have a pivotal role in assisted fecundating programmes as therapy for resolving infertility in domestic animals..........

  8. THE PHOTOPOLYMERIZATION KINETICS OF PHOTOSENSITIZED ACRYLAMIDE SYSTEM INDUCED BY He-Ne LASER

    Institute of Scientific and Technical Information of China (English)

    FENG Minhui; LIANG Zhaoxi; CHEN Yonglie

    1991-01-01

    The kinetics of the photopolymerization of sensitized acrylamide (AM) system induced by He-Ne laser has been investigated. Using methylene blue (MB)-triethanolamine (TEOA) as the photosensitive system, the photopolymerization followed a nonsteady-state kinetic scheme in the initial period of polymerization (the monomer conversion C%<2%) and then followed a steady-state kinetic scheme (5%>C%>2%). According to the steady-state hypothesis, the mechanism of photopolymerization was proposed. The deduced kinetic equation of the photopolymerization of AM is in good coincidence with the experimental results.

  9. The second-order interference of two independent single-mode He-Ne lasers

    CERN Document Server

    Liu, Jianbin; Bai, Bin; Wang, Wentao; Chen, Hui; Zhou, Yu; Li, Fu-Li; Xu, Zhuo

    2014-01-01

    The second-order spatial and temporal interference patterns with two independent single-mode He-Ne lasers are observed in a Hong-Ou-Mandel interferometer. Two-photon interference in Feynman's path integral theory is employed to interpret the experimental results. The conditions to observe the second-order interference pattern with two independent single-mode continuous wave lasers are discussed. It is concluded that two-photon interference exists for not only identical photons, but also photons with different spectrums if the detection system can not distinguish them in principle. The second-order temporal beating with two independent lasers can be employed to measure the coherence time and frequency of one laser if the properties of the other laser were known.

  10. Extra-short He-Ne lasers based on mode split

    Institute of Scientific and Technical Information of China (English)

    韩艳梅; 张书练; 李克兰

    1996-01-01

    An extra-short He-Ne laser (shorter than 100mm) does not work well because there is likely no longitudinal mode in the lasing bandwidth sometimes and the output power rises and falls deeply from time to time.A method to solve this problem has been presented and investigated.A piece of quartz crystal plate appropriately designed is used as a cavity mirror of a He-Ne laser,which has a longitudinal mode spacing larger than the lasing bandwidth to make the equal-spacing mode split.In other words,the number of longitudinal modes is doubled and the actual mode spacing is reduced to the half of that without mode split.Therefore,there is always at least one mode operating in the lasing bandwidth and the power is stable at any room temperature.Such a laser with 85mm cavity length and 0.24mW output power has been made.

  11. Effects of Low Power He-Ne Laser Radiation on Injured Sciatic Nerve

    Directory of Open Access Journals (Sweden)

    D Yarmohammadi

    2001-06-01

    Full Text Available The nervous system has an important and vital role in the human body, but unfortunately the repairment of damaged nervous tissue is very slowly. For a long time, the scientists have been involved in finding ways to speed up this process. Radiation of low power He-Ne laser has been suggested to as a way to improve this issue. In this study, 20 rats were divided randomly into control and case groups. The sciatic nerves of all these rats were damaged under general anesthesia and sterile conditions. The day of surgery was considered as the day zero. Rats of case group received every day laser radiation (?=65 mm. At 27th day rats were killed by ether and the sciatic nerve was studied histologically. Data was analysed and the difference was significant. In the case group the repairment was faster. We concluded that low power He-Ne laser radiation on crushed sciatic nerve of the rats has accelerated the nerve repairment process.

  12. Treatment of 65 patients with cholelithiasis by He-Ne laser acupoint irradiation

    Science.gov (United States)

    Hu, Yong-Jun

    1993-03-01

    The treatment of 65 patients with cholelithiasis by low power helium-neon laser irradiation on acu-points was studied. The results show that 51 of them started to discharge the gallstones within the duration of 6 to 15 laser irradiations, and 11 patients after more than 15 treatments. Two patients (3.1%) were fully cured, 42 (64.6%) markedly effective, 18 (27.7%) effective, and 3 (4.6%) failed. The total effective rate was 95.4%. By chemical analysis, the discharged gallstones were identified as calcium bilirubinate or mixed stones. Patients with stones smaller than 1 cm in diameter or stones made of calcium bilirubinate were more effectively treated than others. The He-Ne laser seems to be a useful treatment for some patients with cholelithiasis without surgical operation.

  13. [Effect of He-Ne-laser irradiation on plasmid transformation of Escherichia coli bacteria].

    Science.gov (United States)

    Tiflova, O A; Leonov, P G; Karbysheva, E A; Shakhnabatian, L G

    1997-01-01

    The influence of the of radiation a He-Ne laser (632.8 nm, 30 W/m2, 5-20 J/m2) on the transformation of Escherichia coli cells with plasmid DNA was studied. The irradiation of a mixture of bacterial cells and plasmid DNA increased the transformation efficiency 2.5-3 times, thus offering an alternative to the heat treatment commonly used. In contrast to the standard techniques, the laser-induced increase in the transformation efficiency was accompanied by a 1.7- to 2-fold increase in cell survival. The effect of the 632.8-nm light, know to be absorbed by membrane porphyrin components, is supposed to be mediated via a modification in the replication and transformation DNA-membrane complexes in E. coli cells.

  14. Pengukuran Daya Laser CO2 Dan Laser DPSS Serta Pengamatan Beam Profiler Sinar Laser DPSS dan Laser He-Ne Menggunakan CCD

    OpenAIRE

    2015-01-01

    This research has done measuring the power by varying the current of laser CO2 and laser DPSS, observation the beam profiler of laser beam DPSS and laser beam He-Ne and observation the spectrum wavelength of laser DPSS and laser He-Ne. In this case of measuring the power by varying the current of laser CO2 and laser DPSS, the measuring has done more than once in order to concluded how the stability of the power that produced by each of the laser. The result of this measuring is laser DPSS ...

  15. Effect of He-Ne laser irradiation on hydrogen production by Enterobacter aerogenes

    Energy Technology Data Exchange (ETDEWEB)

    Lu, Wenyu; Wen, Jianping; Jia, Xiaoqiang; Sun, Bing; Chen, Yu.; Liu, Minhui [Department of Biochemical Engineering, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072 (China)

    2008-01-15

    Enterobacter aerogenes W-23 bacteria exhibiting hydrogen production (HP) ability were exposed to He-Ne laser irradiation (632.8 nm) to improve the HP ability. Upon the optimum irradiation dosage (18 mW for 22.2 min), a stable positive mutant strain E. aerogenes HB-5M was obtained. The maximum specific rate of HP of the mutant strain was 0.042h{sup -1}, which was about twice that of the wild strain. It was suggested that the higher HP ability of the mutant strain might be presumably attributed to the enhancement of hydrogenase activity. In addition, the kinetic parameters of cell growth, substrate consumption and HP of the wild strain and its mutant strain were regressed to simulate the fermentation process of E. aerogenes. The simulated results agreed well with the experimental data. (author)

  16. Controlling the nonlinear intracavity dynamics of large He-Ne laser gyroscopes

    CERN Document Server

    Cuccato, Davide; Belfi, Jacopo; Beverini, Nicolò; Ortolan, Antonello; Di Virgilio, Angela

    2013-01-01

    A model based on Lamb's theory of gas lasers is applied to a He-Ne ring laser gyroscope in order to estimate and remove the laser dynamics contribution from the rotation measurements. The intensities of the counter-propagating laser beams exiting one cavity mirror are continuously observed together with a monitor of the laser population inversion. These observables, once properly calibrated with a dedicated procedure, allow us to estimate cold cavity and active medium parameters driving the main part of the nonlinearities of the system. The parameters identification and noise subtraction procedure has been verified by means of a Monte Carlo study of the system, and experimentally tested on the G-Pisa ring laser oriented with the normal to the ring plane almost parallel to the Earth rotation axis. In this configuration the Earth rotation-rate provides the maximum Sagnac effect while the contribution of the orientation error is reduced at minimum. After the subtraction of laser dynamics by a Kalman filter, the ...

  17. Effects of He-Ne laser on Daphnia magna Straus manifested in subsequent generations

    Science.gov (United States)

    Vorob'yeva, O. V.; Filenko, O. F.; Isakova, E. F.; Vorobieva, N. N.; Rybaltovskii, A. O.; Yusupov, V. I.; Bagratashvili, V. N.

    2015-11-01

    The effects of He-Ne laser irradiation (including visible laser light 632.8 nm in wavelength and an attendant electromagnetic field from the laser apparatus) on the fertility, newborn quality and linear dimensions of the body of Cladocera Daphnia magna Straus were determined. It is shown that the attendant electromagnetic field generated by the laser apparatus can have significant impact on the results of low-intensity laser therapy. The laser light exposure of daphnia to a dose range of 1.7-1300 mJ cm-2 stimulates the integral functions of the daphnia’s body. At the same time, the attendant electromagnetic field (72 mA m-1 in the frequency range of 0.02-20 kHz and 400 mA m-1 in the frequency range of 3-4 MHz) causes the appearance of quickly dying and/or abnormal newborn (up to a small percent) that has never been observed in the control. Anomalies of daphnia mainly consisted of swimming antenna pathologies. Moreover, under the influence of the attendant electromagnetic field on parental daphnia only, these anomalies appear even in several subsequent generations of newborn. The negative impact on daphnia disappears completely after the suppression of the attendant electromagnetic field to laboratory background level. It is shown that laser light can partially compensate the negative impact of the attendant electromagnetic field on Daphnia.

  18. Displacement sensor based on polarization mixture of orthogonal polarized He-Ne laser at 1.15 μm

    Institute of Scientific and Technical Information of China (English)

    Zhengqi Zhao; Shulian Zhang; Peng Zhang; Zhaoli Zeng; Yidong Tan; Yan Li

    2012-01-01

    Displacement sensor based on the polarization mixture and the cavity tuning of the orthogonal polarized He-Ne laser 1.15 μm is presented.The power tuning curves of He-Ne laser are irregular,and it is difficult to measure the change in cavity length.The distortion of the curves is caused by the higher relative excitation compared with the He-Ne laser at 633 nm.In view of its potential for the wider displacement measuring range,a new method of displacement sensing is developed.Experiments show that displacement measuring stability based on the method of the polarization mixture is better than that of the power tuning curves.The displacement sensor achieves the measuring range of 100 mm,resolution of 144 nm,and linearity of 7× 10-6.%Displacement sensor based on the polarization mixture and the cavity tuning of the orthogonal polarized He-Ne laser 1.15 /xm is presented. The power tuning curves of He-Ne laser are irregular, and it is difficult to measure the change in cavity length. The distortion of the curves is caused by the higher relative excitation compared with the He-Ne laser at 633 nm. In view of its potential for the wider displacement measuring range, a new method of displacement sensing is developed. Experiments show that displacement measuring stability based on the method of the polarization mixture is better than that of the power tuning curves. The displacement sensor achieves the measuring range of 100 mm, resolution of 144 nm, and linearity of 7×l0-6.

  19. Clinical observation on the treatment of hemangioma by CO2 laser supplemented with He-Ne laser

    Science.gov (United States)

    Zhao, Zhigui

    1993-03-01

    Sixty-six cases of hemangioma were treated with CO2 laser alone (22 cases as a control group), or CO2 laser supplemented with He-Ne laser (44 cases of the treated group). Optimum power dosage was first sought on normal volunteers. Arteriolar vasculature and lymphatics were blocked 3 - 5 times with procaine hydrochloride (5:1) to minimize local blood congestion. Results show that the healing rate of the treated group was significantly higher than that of the control group (X3 equals 3.92, P hemangioma. Furthermore, it is also proposed that the supplement of copper and Chinese herbal medicines may prevent the incidence of recurrence. Laser was used for the treatment of hemangioma in our country during the 1980s. In foreign literature, there were several reports using Nd:YAG and copper vapor laser for the treatment of agniomasimplex and nevus flammeus. Ar+ laser agglomeration was commonly used for the treatment of angioma conjunctive in our country, but the use of CO2 laser for the treatment of angioma epiderma is not well documented. We wish to report the use of CO2 laser supplemented with He-Ne laser for the treatment of hemangioma in our hospital from April 1988 to December 1989.

  20. Stimulatory effect of He-Ne low dose laser on injured sciatic nerves of rats.

    Science.gov (United States)

    Rochkind, S; Barrnea, L; Razon, N; Bartal, A; Schwartz, M

    1987-06-01

    Injury to a mammalian peripheral nerve is accompanied by a restorative process that is manifested after a delay. This process is expressed morphologically by the emergence of new nerve fibers. Restoration of function occurs when the regenerating fibers reconnect with the target organ. Because of the low rate of fiber elongation, the denervated target is partially degenerated by the time that the regenerating fibers approach it. To prevent such an atrophy, one must find a way to prevent the degeneration of the nerve, to speed up regeneration, or to maintain the target during the period of nerve degeneration. In the present work, we examined the potential of treatment with low energy laser radiation for improving regeneration or preventing degeneration of mammalian peripheral nerve after injury. After repeated injury for 20 consecutive days, treatment of the sciatic nerve of the rat with low energy laser (He-Ne, 17 mW) caused a significant increase in the amplitude of the action potential recorded in the corresponding gastrocnemius relative to the action potential of injured but not treated nerves. The action potential of the injured sciatic nerves that were laser-irradiated increased to values close to that of a noninjured nerve. The studies include follow-up for 1 year after the injury. This electrophysiological manifestation of the effect of laser treatment on injured nerves was accompanied by a diminution of the size of the scar tissue from these nerves. Yet to be resolved is whether these two phenomena (i.e., electrophysiological and morphological responses) coincide or whether they relate to each other.(ABSTRACT TRUNCATED AT 250 WORDS)

  1. Spectroscopic and antimicrobial studies of polystyrene films under air plasma and He-Ne laser treatment

    Indian Academy of Sciences (India)

    S M Pawde; Sanmesh S Parab

    2008-05-01

    Polystyrene (PS) films are used in packaging and biomedical applications because of their transparency and good environmental properties. The present investigation is centered on the antifungal and antibacterial activities involved in the film surface. Subsequently, microbial formations were immobilized on the modified PS films. Living microorganisms such as bacteria and yeast were used. Untreated PS films show very fast rate of growth of bacteria within few hours. The study involves developments of polymer surfaces with bacterial growth and further studies after giving antibacterial treatment such as plasma treatment. Major emphasis has been given to study the effect of various parameters which can affect the performance of the improved material. Films were prepared by two methods: plasma treatment under vacuum and under ongoing He-Ne laser source. The parameters such as (1) surface area by contact angle measurements, (2) quality of material before and after treatment by SEM and FTIR spectra and (3) material characterization by UV-vis spectra were studied. It was observed that plasma treatment of

  2. Effects of He-Ne laser acupuncture-point irradiation on serology hepatitis virus markers in chronic hepatitis B

    Science.gov (United States)

    Wang, Yue-lan; Huang, Bing-chen; Ni, Liu-da

    1993-03-01

    For most of the patients with chronic hepatitis B the immunologic function is deficient. Immunopotentiation and immunoregulation can be used as effective treatments. Laser irradiation can potentiate the cellular immune function of the human body and has good effects on improving clinical symptoms, cutting short the process of diseases, and promoting HBsAg negative change. Thereby we have a randomized opportunity to study the effect of He-Ne laser acupoint irradiation on serological HBV markers (HBVM) in chronic hepatitis B (CHB).

  3. Aquaporin-1-Mediated Effects of Low Level He-Ne Laser Irradiation on Human Erythrocytes

    Directory of Open Access Journals (Sweden)

    Gang-Yue Luo

    2012-01-01

    Full Text Available The role of membrane aquaporin-1 (APQ-1 in the photobiomodulation (PBM on erythrocyte deformability will be studied in this paper with human dehydrated erythrocytes as echinocytic shape alterations lead to decreased cellular deformability. Human dehydrated erythrocytes were irradiated with low intensity He-Ne laser irradiation (LHNL at 0.9, 1.8, 2.7, and 4.4 mW/cm2 for 5, 15, and 30 min, respectively, and APQ-1 inhibitor, 0.2 μmol/L HgCl2, was used to study the role of APQ-1 in mediating PBM with LHNL at 4.4 mW/cm2 for 5 min. Comprehensive morphological parameters of an intact cell such as contact area, perimeter, roundness and erythrocyte elongation index (EEI were measured to characterize erythrocyte deformability with fast micro multi-channel spectrophotometer. It was observed that the dosage of LHNL improvement of the morphological parameters of dehydrated erythrocytes was morphological-parameter-dependent, but the Bunsen-Roscoe rule did not hold for roundness. The LHNL at 4.4 mW/cm2 for 5 min significantly improved the contact area (P<0.05 and EEI (P<0.05 of the dehydrated erythrocytes, but the improvement was significantly inhibited by 0.2 μmol/L HgCl2 (P<0.05. It was concluded that AQP-1 might mediate the effects of LHNL on erythrocyte deformability, which supports the membranotropic mechanism of PBM.

  4. Induction of the Adaptive Response in Mice Exposed to He-Ne Laser and X-Ray Radiation.

    Science.gov (United States)

    Zaichkina, S I; Dyukina, A R; Rozanova, O M; Simonova, N B; Romanchenko, S P; Sorokina, S S; Zakrzhevskaya, D T; Yusupov, V I; Bagratashvili, V N

    2016-05-01

    We studied the dose-dependent induction of in vivo adaptive response in the bone marrow and blood of mice exposed to low-intensity radiation of He-Ne laser (633 nm) and X-ray radiation by the severity of cytogenetic injury and intensity of ROS production, respectively. Induction of the adaptive response in mice preexposed to He-Ne laser and X-ray radiation depended on the adaptive dose and the interval between the adaptive and main doses and correlated with changes in ROS generation. The adaptive response after exposure to low-intensity ionizing and non-ionizing radiation was observed in the same dose range, which attests to similar mechanisms of its induction.

  5. Thirty Cases of Sub-healthy State Regulated by Acupuncture and He-Ne Laser Vascular Irradiation

    Institute of Scientific and Technical Information of China (English)

    Jiang Ying

    2006-01-01

    @@ The sub-healthy state, referred to a functional change without organic pathological process, and also called a third state or a gray state, or the inconstantly described syndromes with subjective discomfort symptoms and psychological experiences, is a transitional stage between the health and illness. In 2003-2004, the author used acupuncture and He-Ne laser vascular irradiation to regulate 30 cases of sub-healthy state. The report is as follows.

  6. SPEED UP THE PROCESS OF HEALING THE OPEN WOUNDS BY LOW POWER HE-NE LASER RADIATION

    Directory of Open Access Journals (Sweden)

    N TAKZARE

    2001-03-01

    Full Text Available Introduction: Reducing pain and enhancement of wound healing have several advantages. Wound healing is a complicated but regular process that includes synchronized and organized phenomena such as paranchyma cells migration, proliferation and synthesis of extracellular matrix proteins. Rate of wound healing is affected by various factors. The aim of our study was to investigate the effects of low power He-Ne laser radiation (630 nm, on metabolic process, cellular proliferation and finally wound repairment. Methods: In our research, about 50 healthy and mature rats were studied by experimental method. After shaving, small cuts (10 mm were made at the neck. Then they were divided randomly into control and case groups. The rats of the case group were radiated by He-Ne laser in the wounds about 4 minutes each day. After a week, we did wound autopsy of both groups and all the specimens were studied microscopically. Results: The findings showed that there were significant increase in the fibroblasts and connective tissue fibers and also vascularisation in the case group compared with the control group. Discussion: Wound healing in the case group was accelerated and wound diameter was smaller significantly. So, low power He-Ne laser radiation accelerates wound healing process.

  7. Effect of low intensity helium-neon (HeNe) laser irradiation on experimental paracoccidioidomycotic wound healing dynamics.

    Science.gov (United States)

    Ferreira, Maria Carolina; Gameiro, Jacy; Nagib, Patrícia Resende Alo; Brito, Vânia Nieto; Vasconcellos, Elza da Costa Cruz; Verinaud, Liana

    2009-01-01

    The effect of HeNe laser on the extracellular matrix deposition, chemokine expression and angiogenesis in experimental paracoccidioidomycotic lesions was investigated. At days 7, 8 and 9 postinfection the wound of each animal was treated with a 632.8 nm HeNe laser at a dose of 3 J cm(-2). At day 10 postinfection, the wounds were examined by using histologic and immunohistochemical methods. Results revealed that laser-treated lesions were lesser extensive than untreated ones, and composed mainly by macrophages and lymphocytes. High IL-1beta expression was shown in the untreated group whereas in laser-treated animals the expression was scarce. On the other hand, the expression of CXCL-10 was found to be reduced in untreated animals and quite intensive and well distributed in the laser-treated ones. Also, untreated lesions presented vascular endothelial growth factor (VEGF) in a small area near the center of the lesion and high immunoreactivity for hypoxia-inducible factor-1 (HIF-1), whereas laser-treated lesions expressed VEGF surrounding blood vessels and little immunoreactivity for HIF-1. Laser-treated lesions presented much more reticular fibers and collagen deposition when compared with the untreated lesion. Our results show that laser was efficient in minimizing the local effects observed in paracoccidioidomycosis and can be an efficient tool in the treatment of this infection, accelerating the healing process.

  8. Study of nonlinear refraction of organic dye by Z-scan technique using He-Ne laser

    Science.gov (United States)

    Medhekar, S.; Kumar, R.; Mukherjee, S.; Choubey, R. K.

    2013-02-01

    Laser induced third-order nonlinear optical responses of Brilliant Green solution has been investigated by utilizing single beam Z-scan technique with a continuous-wave He-Ne laser radiation at 632.8 nm. It was observed that the material exhibits self-defocusing type optical nonlinearity. The measurements of nonlinear refraction were carried out at different dye concentrations and found that the increase in solution concentration leads to the linear increase of the nonlinear refractive index. The experimental results confirm great potential of the Brilliant Green for the application in nonlinear optical devices.

  9. Study of nonlinear refraction of organic dye by Z-scan technique using He-Ne laser

    Energy Technology Data Exchange (ETDEWEB)

    Medhekar, S.; Kumar, R.; Mukherjee, S.; Choubey, R. K. [Dept. of Applied Physics, Birla Institute of Technology, Mesra, Ranchi - 835215, Jharkhand (India)

    2013-02-05

    Laser induced third-order nonlinear optical responses of Brilliant Green solution has been investigated by utilizing single beam Z-scan technique with a continuous-wave He-Ne laser radiation at 632.8 nm. It was observed that the material exhibits self-defocusing type optical nonlinearity. The measurements of nonlinear refraction were carried out at different dye concentrations and found that the increase in solution concentration leads to the linear increase of the nonlinear refractive index. The experimental results confirm great potential of the Brilliant Green for the application in nonlinear optical devices.

  10. ZnO nanofertilizer and He Ne laser irradiation for promoting growth and yield of sweet basil plant.

    Science.gov (United States)

    El-Kereti, Mohammed A; El-feky, Souad A; Khater, Mohammed S; Osman, Yasser A; El-sherbini, El-sayed A

    2013-12-01

    This study was conducted to evaluate the effectiveness of zinc nanofertilizer strategy on sweet basil yield, through alone application or combined with pre-sowing laser irradiation. Furthermore, evaluate the growth of plant and the level of active essential oil constituents. Zinc oxide (ZnO) nanoparticles (NPs) were synthesized, and transmission electron microscope revealed particle size of approximately 10.5-15.5 nm. ZnO NPs were applied to sweet basil plants by foliar spray at varying concentrations (10, 20 and 30 mg/L); He Ne laser of power 3mW was used for red light irradiation of sweet basil seeds for 2 min. exposure time. Total chlorophyll, total carbohydrate, essential oil levels, zinc content, plant height, branches/plant and fresh weight were measured. In general, the combined foliar spray application of ZnO nanofertilizer with pre-sowing He Ne laser irradiation showed more effectiveness than ZnO nanofertilizer alone and 20mg/L concentration gave the highest results of all measured traits. Statistical analysis (t-test) showed significant differences among the effects of the various concentrations of zinc oxide NPs on these attributes. The results showed an inverse relationship between the total carbohydrate content and the percentage of essential oil in the leaves. Together these findings support the usefulness and effectiveness of zinc oxide nanofertilizer and laser irradiation treatment to enhance the growth and yield of sweet basil plants. The article presents some promising patents on ZnO nanofertilizer and He Ne laser irradiation.

  11. Structural and cytochemical modifications in the lingual glands of the newborn chicken irradiated with He-Ne laser.

    Science.gov (United States)

    Avila, R E; Samar, M E; de Fabro, S P; Plivelic, T S

    1997-01-01

    Despite the increasing and successful use of laser in Medicine and Odontology, the possible iatrogenic and otherwise deleterious side effects of this radiation remain mostly unknown. In previous studies, it was shown that both the embryonic and the post-hatched chicken constitute reliable experimental models for this type of studies. Hence, the purpose of the present work was to analyze the structural and cytochemical alterations of the lingual glands of the newborn chicken irradiated with low energy He-Ne laser. This laser produced regressive structural changes of the glands towards the embryonic stage as well as hyperplasia of the reserve glandular basal cells. Furthermore, a decrease in the glycoprotein content and a rise in the sulphated glycosaminoglycans were also found. These results corroborate the pathogenic effects of the He-Ne- laser on the experimental model employed and, at the same time, emphasize the importance of considering, regarding clinical applications, possible previous neoplastic alterations as well as adverse reactions which might appear once laser therapy has been installed.

  12. Phase control of a Zeeman-split He-Ne gas laser by variation of the gaseous discharge voltage.

    Science.gov (United States)

    Shelton, W N; Hunt, R H

    1992-07-20

    Zeeman-split lasers are useful for precise positioning or motion control. In applications that employ such a laser to control closely the position of a moving system, phase noise in the Zeeman frequency is a serious problem. Control of low-frequency phase noise can be obtained through variation of the external magnetic field by way of a solenoid wound around the laser tube. It is the finding in this work that control of the residual higher-frequency noise of a He-Ne laser can be obtained through small variations of the high voltage that is used to effect the gaseous discharge in the laser tube. The application of the present system is to the control of the path difference in a Fourier-transform interferometric spectrometer.

  13. He-Ne laser-induced improvement in biochemical, physiological, growth and yield characteristics in sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Perveen, Rashida; Jamil, Yasir; Ashraf, Muhammad; Ali, Qasim; Iqbal, Munawar; Ahmad, Muhammad Raza

    2011-01-01

    The water-soaked seeds of sunflower were exposed to low power continuous wave He-Ne laser irradiation of energies 0, 100, 300 and 500 mJ to evaluate the effect on various biochemical, physiological, growth and yield parameters of sunflower. The experiments which consisted of four replicates arranged in a completely randomized design (CRD) were carried out under the greenhouse conditions. The physiological attributes like, photosynthetic rate (A), transpiration rate (E), intrinsic CO(2) concentration (C(i) ), stomatal conductance (g(s)), chlorophyll a and b contents, relative membrane permeability and leaf water (ψ(w)), osmotic (ψ(s)) and turgor (ψ(p)) potentials, relative water contents and leaf area increased significantly as compared to control due to He-Ne treatment of seeds. The activities of superoxide dismutase, peroxidase and catalases and contents of total soluble proteins, malondialdehyde, proline and leaf total phenolic also increased due to laser treatment. Significant increase in growth parameters of sunflower like shoot fresh and dry masses, root fresh and dry masses, root and shoot lengths, number of leaves per plant and stem diameter has also been observed. The contents of K, Ca and Mg in shoot and root were also increased and an overall increase of up to 28.12% was observed due to laser treatment.

  14. Effects of Chinese Herbal Medicine Combined with He-Ne Laser on Lipoperoxide and Superoxide Dismutase in Chloasma Patients

    Institute of Scientific and Technical Information of China (English)

    WU Yan-hua; LI Qi-lin; YANG Xiu-wen

    2009-01-01

    Objective:To observe the effects of Chinese decoction and ligustrazin hydrochloride injection combined with He-Ne laser on lipoperoxide (LPO) and Superoxide dismutase (SOD) in patients with chloasma.Methods:90 cases of chloasma were randomly divided into the following two groups:a treatment group (of 54 cases) treated by a self-prepared prescription for toning the kidneys and relieving the depressed liver to remove blood stasis, ligustrazin hydrochloricde injection and He-Ne laser therapy, and a control group (of 36 cases) treated with oral administration of Vitamin E and Vitamin C plus external application of 20% Azelaic acid cream.Results:The total effective rate in the treatment group was 79.6%, which was significantly higher than that of the control group (P<0.05).After treatment, the LPO level in the treatment group was significantly lowered (P<0.01), and the SOD level was significantly elevated (P<0.05).Conclusion:The therapeutic methods adopted in the treatment group may show the action of antioxidation, providing good clinical effects for treating chloasma.

  15. He-Ne 激光的波长检测及稳频技术--激光干涉仪技术综述之二%He -Ne Laser Wavelength Testing and Frequency Stabilization Technique

    Institute of Scientific and Technical Information of China (English)

    羡一民

    2014-01-01

    The principle of the frequency stabilization and the wavelength detection method in the He -Ne laser are introduced.Several typical frequency -stabilization systems are analyzed.Those systems are based on different effects such as the Longitudinal Zeeman,Transverse Zeeman,Lamb Sag and Double Longitudinal Mode.%介绍了 He -Ne 激光的稳频原理及波长检测方法,分析了 Lamb 凹陷、纵向塞曼、横向塞曼及双纵模等几种典型的稳频系统的技术特点。

  16. Effect of He-Ne laser irradiation on spontaneous contractive activity and basal tone level of rat portal vein

    Science.gov (United States)

    Petrishchev, Nikolai N.; Barabanova, Valeria V.; Mikhailova, Irina A.; Chephu, Svetlana G.

    2000-11-01

    To study the effect of He-Ne irradiation (632.8 nm, 15 mW/cm2) on spontaneous contractive activity the fragments of rat portal vein weremounted isometrically in Krebs buffer. Irradiation of vessel fragments by He-Ne laser during 3,5 and 10 min caused the decrease of ton up to 50%, which lasted in postirradiation period (the observation time - 10 min). The frequency of phasic and tonic contractions did not change, but the amplitude increased up to 40% as compared to the initial level. The decreased basal tone level and the increased amplitude of phasic oscillations lasted in postirradiation period. Adding NO synthasa blocator (N - nitro-L-arginine) to Krebs solution before irradiation caused no significant changes mentioned above parameters. Irradiation and coputing of the same parameters of spontaneous contractive activity of vena porta caused no effects, mentioned in the absence of the blocator. From the results it is concluded that the decrease of tone is evoked by the increase of EDRF production and cGMP. The increase of amplitude of phasic and tonic contractions is connected with increase of Ca++ entry in every contraction cycle as a result of membrane Ca++ pool increase.

  17. A combination of He-Ne laser irradiation and exogenous NO application efficiently protect wheat seedling from oxidative stress caused by elevated UV-B stress.

    Science.gov (United States)

    Li, Yongfeng; Gao, Limei; Han, Rong

    2016-12-01

    The elevated ultraviolet-B (UV-B) stress induces the accumulation of a variety of intracellular reactive oxygen species (ROS), which seems to cause oxidative stress for plants. To date, very little work has been done to evaluate the biological effects of a combined treatment with He-Ne laser irradiation and exogenous nitric oxide (NO) application on oxidative stress resulting from UV-B radiation. Thus, our study investigated the effects of a combination with He-Ne laser irradiation and exogenous NO treatment on oxidative damages in wheat seedlings under elevated UV-B stress. Our data showed that the reductions in ROS levels, membrane damage parameters, while the increments in antioxidant contents and antioxidant enzyme activity caused by a combination with He-Ne laser and exogenous NO treatment were greater than those of each individual treatment. Furthermore, these treatments had a similar effect on transcriptional activities of plant antioxidant enzymes. This implied that the protective effects of a combination with He-Ne laser irradiation and exogenous NO treatment on oxidative stress resulting from UV-B radiation was more efficient than each individual treatment with He-Ne laser or NO molecule. Our findings might provide beneficial theoretical references for identifying some effective new pathways for plant UV-B protection.

  18. Frequency stabilization of ambience-isolated internal-mirror He-Ne lasers by thermoelectric-cooling thermal compensation

    Science.gov (United States)

    Shirvani-Mahdavi, Hamidreza; Narges, Yaghoubi

    2016-12-01

    An approach for frequency stabilization of an ambience-isolated internal-mirror He-Ne laser (632.8 nm) utilizing temperature control of the laser tube with Peltier thermoelectric coolers is demonstrated. Measurements indicate that there are an optimal temperature (23 °C) and an optimal discharge current (5.5 mA) of laser tube for which the laser light power is separately maximized. To prevent the effect of fluctuation of discharge current on the laser stability, an adjustable current source is designed and fabricated so that the current is set to be optimal (5.50 ± 0.01 mA). To isolate the laser tube from the environment, the laser metallic box connected to two Peltier thermoelectric coolers is surrounded by two thermal and acoustic insulator shells. The laser has two longitudinal modes very often. Any change in the frequency of longitudinal modes at the optimal temperature is monitored by sampling the difference of longitudinal modes' intensities. Therefore, using a feedback mechanism, the current of thermoelectric coolers is so controlled that the frequency of modes stays constant on the gain profile of the laser. The frequency stability is measured equal to 1.17 × 10-9 (˜2700×) for less than 1 min and 2.57 × 10-9 (˜1200×) for more than 1 h.

  19. Frequency stabilization of ambience-isolated internal-mirror He-Ne lasers by thermoelectric-cooling thermal compensation

    Science.gov (United States)

    Saha, Asit; Pal, Nikhil; Saha, Tapash; Ghorui, M. K.; Chatterjee, Prasanta

    2016-08-01

    An approach for frequency stabilization of an ambience-isolated internal-mirror He-Ne laser (632.8 nm) utilizing temperature control of the laser tube with Peltier thermoelectric coolers is demonstrated. Measurements indicate that there are an optimal temperature (23 °C) and an optimal discharge current (5.5 mA) of laser tube for which the laser light power is separately maximized. To prevent the effect of fluctuation of discharge current on the laser stability, an adjustable current source is designed and fabricated so that the current is set to be optimal (5.50 ± 0.01 mA). To isolate the laser tube from the environment, the laser metallic box connected to two Peltier thermoelectric coolers is surrounded by two thermal and acoustic insulator shells. The laser has two longitudinal modes very often. Any change in the frequency of longitudinal modes at the optimal temperature is monitored by sampling the difference of longitudinal modes' intensities. Therefore, using a feedback mechanism, the current of thermoelectric coolers is so controlled that the frequency of modes stays constant on the gain profile of the laser. The frequency stability is measured equal to 1.17 × 10-9 (˜2700×) for less than 1 min and 2.57 × 10-9 (˜1200×) for more than 1 h.

  20. Reactive Effect of Low Intensity He-Ne Laser upon Damaged Ultrastructure of Human Erythrocyte Membrane in Fenton System by Atomic Force Microscopy

    Institute of Scientific and Technical Information of China (English)

    Yanhong CUI; Zhouyi GUO; Yanping ZHAO; Ying ZHENG; Yanfang QIAO; Jiye CAI; Songhao LIU

    2007-01-01

    To find out the mechanism of modulating the deformability of erythrocytes with low intensity He-Ne laser action, we studied the effect of low intensity He-Ne laser on the ultrastructure of human erythrocyte membrane. Erythrocytes were treated with free radicals from a Fenton reaction system before exposing them to low intensity He-Ne laser. The ultrastructure of damaged erythrocyte membrane was examined by atomic force microscopy. The results showed that the erythrocyte membrane became very rough and the molecules on the surface of the membrane congregated into particles of different magnitudes sizes after treating with free radicals. Comparing the degree of congregation of the molecular particles in the non-irradiated group and the He-Ne laser irradiated (9 mW and 18 mW) group, we found the average size of molecular particles in the laser irradiated group was smaller than that in the non-irradiated group, indicating that the low intensity laser had repairing function to the damage of erythrocyte membrane produced by the free radicals.

  1. Effect of low-energy laser (He-Ne) irradiation on embryo implantation rate in the rat

    Science.gov (United States)

    Stein, Anat; Kraicer, P. F.; Oron, Uri

    1997-12-01

    Attempts to date to increase the rate of embryo implantation, for example by assisting embryo hatching from the zona pellucida, have failed. Recently, several studies have suggested the biostimulating effect of low power laser irradiation. The objective of this study was therefore to examine the potential of low power laser irradiation of the uterus to enhance embryo implantation rate in the rat. Rat potential of low power laser irradiation of the uterus to enhance embryo implantation rate in the rat. Rat blastocysts were flushed from the uterus on day 5 of gestation. They were transferred to the uteri of pseudopregnant recipients on day 4 or 5 of pseudopregnancy. One cornu of the recipient uterus was irradiated; the other was used as control. On day 5 of pregnancy, irradiation did not change implantation rate after 10 or 30 sec of irradiation while 120 sec. of irradiation significantly decreased embryonic implantation. On the other hand, on day 4 of pregnancy, 120 sec. of radiation allowed embryonic implantation to a level similar to that seen after synchronized transfer. Conclusion: He-Ne laser irradiation of the exposed rat uterus can attenuate embryo implantation rate.

  2. Determination of total polyphenolic content in red wines by means of the combined He-Ne laser optothermal window and Folin-Ciocalteu colorimetric assay

    NARCIS (Netherlands)

    Doka, O.; Bicanic, D.

    2002-01-01

    The He-Ne laser (632.8 nm) and the concept of optothermal window (OW), a variant of the open photoacoustic cell, were combined with the Folin-Ciocalteu colorimetry assay to quantitate phenolics in four red wines. The total polyphenolic content in selected red wines varied between 786 and 1630 mg/L g

  3. The influence of low-intensity He-Ne laser on the wound healing in diabetic rats.

    Science.gov (United States)

    Eissa, Maha; Salih, Wasil H M

    2017-08-01

    The low-level laser irradiation at certain wavelengths is reported to facilitate the healing process of diabetic wounds. Thus, this study carried out to look for the suitable laser parameters that could speed up the healing process. Fourteen healthy male and female rats were used in which a circular wound with a diameter of 2.5 ± 0.2 cm was created on the dorsum in each rat after injected them with alloxan to induced diabetic. They have been divided into two groups: control group (N = 7) and study group (N = 7) to conduct the study. He-Ne laser with a wavelength of 632.8 nm at power density of 4.0 mW/cm(2) was used to irradiate the study group for five times a week until the wound healed (closed) completely, while the control group was kept untreated. The results showed that the laser-treated group healed (wounds were totally closed) faster compared to the control group. In numbers, the laser-treated group healed on average at the 21st day (0.0 ± 0.0 cm) (P ≤ 0.005), whereas the control group healed after 40 days or even 60 days in some cases (sample no. 2). This confirms that laser promotes the tissue repair process of diabetic wounds and reduces the healing period to the half.

  4. Research on optical properties of dental enamel for early caries diagnostics using a He-Ne laser

    Science.gov (United States)

    Tang, Jing; Liu, Li; Li, Song-zhan

    2008-12-01

    A new and non-invasive method adapted for optical diagnosis of early caries is proposed by researching on the interaction mechanism of laser with dental tissue and relations of remitted light with optical properties of the tissue. This method is based on simultaneous analyses of the following parameters: probing radiation, backscattering and auto-fluorescence. Investigation was performed on 104 dental samples in vitro by using He-Ne laser (λ=632.8nm, 2.0+/-0.1mW) as the probing. Spectrums of all samples were obtained. Characteristic spectrums of dental caries in various stages (intact, initial, moderate and deep) were given. Using the back-reflected light to normalize the intensity of back-scattering and fluorescence, a quantitative diagnosis standard for different stages of caries is proposed. In order to verify the test, comparison research was conducted among artificial caries, morphological damaged enamel, dental calculus and intact tooth. Results show that variations in backscattering characteristic changes in bio-tissue morphological and the quantity of auto-fluorescence is correlated with concentration of anaerobic microflora in hearth of caries lesion. This method poses a high potential of diagnosing various stages of dental caries, and is more reliability to detect early caries, surface damage of health enamel and dental calculus.

  5. Free radical erythrocyte damage in tumoral disease assessed by He-Ne laser and optical microscope through "Heinz Bodies" method.

    Science.gov (United States)

    Broccio, M; Della Rovere, F; Granata, A; Wanderlingh, U; Zirilli, A; Tanzariello, A; Pirrone, G; Broccio, G

    1998-01-01

    Results obtained from blood sample readings by optical microscopy and He-Ne laser (lambda = 630.1 mW), have confirmed the reduction in Heinz Bodies (HB) formation time and the Transmittance Reduction Degree (TRD), in malignancies. The results of spectrometric readings in colorectum polyposis, (TRD = 0.07) and fibrocystic mastopathy (TRD = 0.08) gave results overlapping with controls (TRD = 0.08). In neoplasias, the early HB formation in erythrocytes observed by optical microscope corresponded to TRD increase = 0.17 (P < 0.01). TRD increase was statistically significant (P < 0.01), as well as the reduction in the time of HB appearance (< 0.01). The relationship between optical and laser readings was exponential in tumors, while it was linear in controls, in polyposis and mastopathies. The values of the correlation coefficients obtained by both methods were significant (P < 0.01) for all the studied groups. Moreover, these research data further support the existence, even in the earlier stages of the disease, of the labile state of the red cell membrane due to strong lipid peroxidation by FRs.

  6. Bullet Design and Fabrication of Dual Mode Pyroelectric Sensor: High Sensitive Energymeter for Nd: YAG Laser and Detector for Chopped He-Ne Laser

    Directory of Open Access Journals (Sweden)

    S. SATAPATHY

    2008-05-01

    Full Text Available Pyroelectric sensor using TGS has been designed and fabricated which can be operated in laser energy meter mode as well as pyroelectric detector mode. The amplifying circuit configuration has very good signal to noise ratio, very high input impedance and low drift. The pyroelectric sensor has been tested using Q-switched Nd: YAG laser and chopped He-Ne laser. The sensitivity of pyroelectric sensor in energymeter mode is 421.7V/J and the voltage responsivity of the pyroelectric sensor is 3.27 V/W in detector mode.

  7. Responses of He-Ne laser irradiation on agronomical characters and chlorogenic acid content of brinjal (Solanum melongena L.) var. Mattu Gulla.

    Science.gov (United States)

    Swathy, Surendrababu P; Kiran, Kodsara Ramachandra; Rao, Madhura S; Mahato, Krishna K; Rao, Mattu Radhakrishna; Satyamoorthy, Kapaettu; Muthusamy, Annamalai

    2016-11-01

    Exposure to laser irradiation on seeds brings about the changes in agronomical characteristics of the plants. Solanum melongena L. var. Mattu Gulla, a variety of brinjal is of high economic value due to its unique colour and flavour. The aim of the study was to understand the influence of Helium-Neon (He-Ne) laser irradiation on agronomical characters of Solanum melongena L. var. Mattu Gulla in the field conditions. Various growth characteristics including seed germination percentage, survival rate, plant height, number of branches, and flowers and fruits were estimated during different developmental stages of the brinjal. In addition, the chlorogenic acid content of fruits obtained from the laser irradiated seeds were quantified using reversed-phase high-performance liquid chromatography (RP- HPLC). The plants from the seeds irradiated with different doses (20, 25 and 30J/cm(2)) of He-Ne laser showed significant enhancement on the growth characteristics when compared to the non-irradiated control groups. He-Ne laser irradiation also improved the yield characteristics of the plants significantly in in vivo conditions in comparison with control group. 3-(4, 5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed using methanolic extract of matured fruit of Mattu Gulla on HepG2 and fibroblast cell lines. The IC50 values of fruit extract from laser irradiated groups were found to be similar to non-irradiated control groups. Chlorogenic acid content was found to be higher in 20J/cm(2) and lower in 30J/cm(2) treated fruit tissue. The current study thus elucidates the role of He-Ne laser as a biostimulator on brinjal var. Mattu Gulla not only in the in vitro conditions but also in the in vivo field conditions.

  8. Influence of He-Ne laser therapy on the dynamics of wound healing in mice treated with anti-inflammatory drugs

    Directory of Open Access Journals (Sweden)

    W.L.S. Gonçalves

    2007-06-01

    Full Text Available We determined the effects of helium-neon (He-Ne laser irradiation on wound healing dynamics in mice treated with steroidal and non-steroidal anti-inflammatory agents. Male albino mice, 28-32 g, were randomized into 6 groups of 6 animals each: control (C, He-Ne laser (L, dexamethasone (D, D + L, celecoxib (X, and X + L. D and X were injected im at doses of 5 and 22 mg/kg, respectively, 24 h before the experiment. A 1-cm long surgical wound was made with a scalpel on the abdomens of the mice. Animals from groups L, D + L and X + L were exposed to 4 J (cm²-1 day-1 of He-Ne laser for 12 s and were sacrificed on days 1, 2, or 3 after the procedure, when skin samples were taken for histological examination. A significant increase of collagen synthesis was observed in group L compared with C (168 ± 20 vs 63 ± 8 mm². The basal cellularity values on day 1 were: C = 763 ± 47, L = 1116 ± 85, D = 376 ± 24, D + L = 698 ± 31, X = 453 ± 29, X + L = 639 ± 32 U/mm². These data show that application of L increases while D and X decrease the inflammatory cellularity compared with C. They also show that L restores the diminished cellularity induced by the anti-inflammatory drugs. We suggest that He-Ne laser promotes collagen formation and restores the baseline cellularity after pharmacological inhibition, indicating new perspectives for laser therapy aiming to increase the healing process when anti-inflammatory drugs are used.

  9. 氦氖激光对几种溶液粘度的影响%Effect on the viscosity of solutions by He-Ne laser

    Institute of Scientific and Technical Information of China (English)

    杨颖; 马勇; 耿虹; 闫秀英

    2001-01-01

    目的:探讨氦氖激光对蒸馏水、自来水、NaCl溶液、葡萄糖溶液粘度的影响。方法:以特定的激光强度、经不同的照射时间处理溶液,用奥氏粘度计测定溶液的粘度。结果与结论:激光对蒸馏水和NaCl溶液粘度无明显影响。激光对自来水粘度的影响随照射时间的不同呈双向结果,照射时间在10 min以内粘度低于对照组,差异显著(P 0.05)。%To probe into the effect on the viscosity of distilled water natural water Nacl solution and glucose solution by He-Ne Laser. Ubbohde's viscosimeter was used to examine the solutions treated by different times of irradiation under the action of certain Laser power to determine its viscosity. He-Ne Laser has not an effect on the viscosity of distilled water and NaCl solution. Effect on the viscosity of the natural water by He-Ne Laser ,the irradiating times in ten minutes, the viscosity of natural water is markedly lower than that from control groups, which are significantly different(P 0.05)

  10. The post-thaw irradiation of avian spermatozoa with He-Ne laser differently affects chicken, pheasant and turkey sperm quality.

    Science.gov (United States)

    Iaffaldano, N; Paventi, G; Pizzuto, R; Passarella, S; Cerolini, S; Zaniboni, L; Marzoni, M; Castillo, A; Rosato, M P

    2013-11-30

    The effects of post-thaw Helium-Neon (He-Ne) laser irradiation on mobility and functional integrity of frozen/thawed chicken, pheasant and turkey spermatozoa were investigated. Cytochrome C oxidase (COX) activity was also determined as a measure of the effect of irradiation on mitochondrial bioenergetics. Semen samples from each species were collected, processed and frozen according to the pellet procedure. After thawing, each semen sample was divided into two subsamples: the first one was the control; the second one was irradiated with a single mode continuous He-Ne laser wave (wavelength 632.8 nm; 6 mW; 3.96 J/cm(2)). Then the samples were assessed for sperm mobility (Accudenz(®) swim-down test), viability (SYBR-14/PI staining), osmotic-resistance (HOS test) and COX activity. The irradiation was effective Psperm motility in the turkey semen (0.228 ± 0.01 compared with 0.294 ± 0.02). The irradiation also caused an increase (Psperm, without affecting viability and osmotic-resistance. The COX was positively correlated (Psperm, however no significant interactions were found between mobility and COX activity in the three avian species. Due to the difference in energetic metabolism among avian species used in this study, the He-Ne laser irradiation has a differential action on bio-stimulation of turkey, chicken and pheasant spermatozoa. The present results are the first to elucidate the possibility for restoration of motility of cryopreserved avian spermatozoa by bio-stimulation provided via He-Ne laser irradiation.

  11. Two-chord interferometry using 3.39 {mu}m He-Ne laser on a flux-coil-generated FRC

    Energy Technology Data Exchange (ETDEWEB)

    Gota, H.; Deng, B. H.; Gupta, D.; Kiyashko, V.; Knapp, K.; Mendoza, R.; Morehouse, M. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Bolte, N.; Roche, T.; Wessel, F. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States)

    2010-10-15

    A two-chord {lambda}{sub IR}{approx}3.39 {mu}m He-Ne laser interferometer system was developed for a flux-coil-generated field-reversed configuration to estimate the electron density and the total temperature of the field-reversed configuration (FRC) plasma. This two-chord heterodyne interferometer system consists of a single {approx}2 mW infrared He-Ne laser, a visible ({lambda}{sub vis}{approx}632.8 nm) He-Ne laser for the alignment, a 40 MHz acousto-optic modulator, photodetectors, and quadrature phase detectors. Initial measurement was performed and the measured average electron densities were 2-10x10{sup 19} m{sup -3} at two different radial positions in the midplane. A time shift in density was observed as the FRC expands radially. The time evolution of the line-averaged density agrees with the density estimated from the in situ internal magnetic probes, based on a rigid-rotor profile model.

  12. Two-chord interferometry using 3.39 μm He-Ne laser on a flux-coil-generated FRC.

    Science.gov (United States)

    Gota, H; Bolte, N; Deng, B H; Gupta, D; Kiyashko, V; Knapp, K; Mendoza, R; Morehouse, M; Roche, T; Wessel, F

    2010-10-01

    A two-chord λ(IR)∼3.39 μm He-Ne laser interferometer system was developed for a flux-coil-generated field-reversed configuration to estimate the electron density and the total temperature of the field-reversed configuration (FRC) plasma. This two-chord heterodyne interferometer system consists of a single ∼2 mW infrared He-Ne laser, a visible (λ(vis)∼632.8 nm) He-Ne laser for the alignment, a 40 MHz acousto-optic modulator, photodetectors, and quadrature phase detectors. Initial measurement was performed and the measured average electron densities were 2-10×10(19) m(-3) at two different radial positions in the midplane. A time shift in density was observed as the FRC expands radially. The time evolution of the line-averaged density agrees with the density estimated from the in situ internal magnetic probes, based on a rigid-rotor profile model.

  13. The effect of He-Ne and Ga-Al-As lasers on the healing of oral mucosa in diabetic mice.

    Science.gov (United States)

    Fahimipour, Farahnaz; Houshmand, Behzad; Alemi, Parvin; Asnaashari, Mohammad; Tafti, Mahmoud Akhavan; Akhoundikharanagh, Fatemeh; Farashah, Seyed Emadeddin Najafi; Aminisharifabad, Mohammad; Korani, Aghdas Setoudehnia; Mahdian, Mina; Bastami, Farshid; Tahriri, Mohammadreza

    2016-06-01

    Delayed wound healing is one of the complications of diabetes mellitus. Low-level laser therapy (LLLT) has been used to accelerate wound healing however the effect of LLLT on the hard palate wound healing in streptozotocin-induced diabetic (STZ-D) mice has not yet been characterized. This study aims to determine the effect of LLLT (He-Ne and Ga-Al-As laser) on the process of wound healing in the hard palate among diabetic and non-diabetic mice. 90 adult male mice were divided into six groups. Type 1 diabetes mellitus was induced in three groups by means of injection of STZ. Of these, one group was irradiated with He-Ne laser (DH group), one with Ga-Al-As laser (DG group) and one did not undergo any LLLT (DC group). The remaining groups were non-diabetic which were allotted to laser therapy with He-Ne laser (NH group) or with Ga-Al-As laser (NG group) or no LLLT (NC group). Five animals from each group were killed on the third, seventh, and fourteenth days after surgery, and biopsies were made for histological analysis. On the 3rd and 7th days after the surgery, the number of polymorphonuclear (PMN) cells in NH, DH, NG, and DG groups was significantly lower than that of the control groups. On the 3rd, 7th and 14th days, the fibroblasts and new blood vessel counts and collagen fibers in diabetic laser treated groups (DG and DH) were significantly higher compared to that of NC, DC, NH and NG groups. On the 7th and 14th days, the fibroblasts and new blood vessel counts and collagen fibers in NH, DH, NG, and DG groups were also significantly higher than that of the control groups, and the fibroblast and new blood vessel counts and collagen density fibers in NH and DH groups were higher than that of the NG and DG groups. LLLT with He-Ne laser compared to Ga-Al-As laser has a positive healing effect on hard palate gingival wounds in STZ-D mice.

  14. Mechanism research of eye injury induced by He-Ne laser irradiation%氦氖激光辐照致眼损伤的机制研究

    Institute of Scientific and Technical Information of China (English)

    梁洁; 陈鹏; 闫文华; 马萍; 方毅; 康宏向; 高荣莲; 王长振

    2013-01-01

    [Objective]To explore the mechanism of He-Ne laser on rat eyes damage. [Methods]The model of rat eyes damage by He-Ne laser was established. Through examination of histopathology, TUNEL and in situ hybridization (ISH) , the expression of glutamate receptor (NMDAR) and changes in retinal cell structure were observed. [Results] Observation under the optical microscope showed disorders of the organizational structure, apoptosis of photoreceptor cells and increased expression of NMDAR in retina after exposure to laser. [Conclusion]Under given conditions, He-Ne laser irradiation can cause retina pathological changes, the excessive release of glutamateand and high expressions on NMDAR may be the possible mechanism of damage to the photoreceptor cells.%目的 探讨氦氖激光致眼损伤效应及可能的作用机制.方法 建立氦氖激光的大鼠眼损伤模型,通过组织病理染色、凋亡检测以及原位杂交等方法,观察激光照后视网膜细胞结构变化及谷氨酸受体(NMDAR)的表达.结果 光学显微镜下观察显示激光照后视网膜出现组织结构的紊乱和感光细胞的凋亡,同时伴有NMDAR mRNA的高表达.结论 氦氖激光在一定的条件下可造成视网膜的病理性损伤,损伤局部谷氨酸的过度释放及NMDAR受体的高表达可能是感光细胞受损的重要机制.

  15. A efetividade do laser de HeNe 632,8 nm no reestabelecimento da integridade dos tecidos cutâneos em animais experimentais: revisão sistemática Effectiveness of HeNe 632.8 nm laser on skin tissue integrity repair in experimental animals: a systematic review

    Directory of Open Access Journals (Sweden)

    Clarissa Tôrres Leal

    2012-09-01

    Full Text Available O objetivo desta revisão sistemática foi analisar o efeito do laser de HeNe na cicatrização de feridas em ratos. Foram selecionados estudos experimentais que adotaram o laser HeNe para o tratamento de feridas agudas em ratos adultos saudáveis, com lesões induzidas por bisturi, nas bases de dados PubMed/MEDLINE, LILACS e SciELO. Foram utilizados os seguintes descritores: cicatrização de feridas e colágeno, de acordo com o MeSH e o DeCS, além dos unitermos laser HeNe e reparação da pele e seus equivalentes em inglês e espanhol. Três estudos foram incluídos na revisão sistemática, não sendo possível a realização de metanálise, devido à impossibilidade de comparação entre as metodologias dos estudos selecionados. Todos os estudos realizaram análise por meio de cortes histológicos das cicatrizes. A presença de falhas metodológicas nos três artigos dificultou a interpretação fidedigna dos dados encontrados. Os estudos destacaram uma redução na intensidade da resposta inflamatória e uma melhor organização das fibras colágenas no grupo irradiado. A terapia com laser HeNe mostrou boa resposta no reparo tecidual. No entanto, tais resultados devem ser analisados de modo criterioso, uma vez que há presença de heterogeneidade, principalmente em relação aos parâmetros adotados.The aim of this systematic review was to analyze the effect of HeNe laser on wound healing in rats. Experimental studies that adopted HeNe laser as a treatment of acute lesions in healthy adult rats were selected, with scalpel-induced lesions, at PubMed/MEDLINE, LILACS, and SciELO databases. The following keywords were used: wound healing and collagen, according to MeSH and DeCS, besides the terms HeNe laser and skin repair, and their equivalent in Portuguese and Spanish. Three studies were included in this systematic review, but it was not possible to perform a metanalysis, due to impossibility to compare methods of the selected studies. All

  16. Humidity coefficient correction in the calculation equations of air refractive index by He-Ne laser based on phase step interferometry.

    Science.gov (United States)

    Chen, Qianghua; Liu, Jinghai; He, Yongxi; Luo, Huifu; Luo, Jun; Wang, Feng

    2015-02-10

    The refractive index of air (RIA) is an important parameter in precision measurement. The revisions to Edlen's equations by Boensch and Potulski [Metrologia 35, 133 (1998)] are mostly used to calculate the RIA at present. Since the humidity correction coefficients in the formulas were performed with four wavelengths of a Cd(114) lamp (644.0, 508.7, 480.1, and 467.9 nm) and at the temperature range of 19.6°C-20.1°C, the application is restricted when an He-Ne laser is used as the light source, which is mostly applied in optical precision measurement, and the environmental temperature is far away from 20°C as well. To solve this problem, a measurement system based on phase step interferometry for measuring the effect of the humidity to the RIA is presented, and a corresponding humidity correction equation is derived. The analysis and comparison results show that the uncertainty of the presented equation is better than that of Boensch and Potulski's. It is more suitable in present precision measurements by He-Ne laser, and the application temperature range extends to 14.6°C-24.0°C as well.

  17. Effects of different doses of low power continuous wave he-ne laser radiation on some seed thermodynamic and germination parameters, and potential enzymes involved in seed germination of sunflower (Helianthus annuus L.).

    Science.gov (United States)

    Perveen, Rashida; Ali, Qasim; Ashraf, Muhammad; Al-Qurainy, Fahad; Jamil, Yasir; Raza Ahmad, Muhammad

    2010-01-01

    In this study, water-soaked seeds of sunflower were exposed to He-Ne laser irradiation of different energies to determine whether or not He-Ne laser irradiation caused changes to seed thermodynamic and germination parameters as well as effects on the activities of germination enzymes. The experiment comprised four energy levels: 0 (control), 100, 300 and 500mJ of laser energy and each treatment replicated four times arranged in a completely randomized design. The experimentation was performed under the greenhouse conditions in the net-house of the Department of Botany, University of Agriculture, Faisalabad. The seed thermodynamic parameters were calculated according to seed germination thermograms determined with a calorimeter at 25.8°C for 72h. Various thermodynamic parameters of seed (ΔH, (ΔS)(e), (ΔS)(c), (ΔS)(e) /Δt and (ΔS)(c) /Δt) were affected significantly due to presowing laser treatment. Significant changes in seed germination parameters and enzyme activities were observed in seeds treated with He-Ne laser. The He-Ne laser seed treatment resulted in increased activities of amylase and protease. These results indicate that the low power continuous wave He-Ne laser light seed treatment has considerable biological effects on seed metabolism. This seed treatment technique can be potentially employed to enhance agricultural productivity.

  18. The Laser-assisted photoelectric effect of He, Ne, Ar and Xe in intense extreme ultraviolet and infrared laser fields

    Science.gov (United States)

    Hayden, P.; Dardis, J.; Hough, P.; Richardson, V.; Kennedy, E. T.; Costello, J. T.; Düsterer, S.; Redlin, H.; Feldhaus, J.; Li, W. B.; Cubaynes, D.; Meyer, M.

    2016-02-01

    In this paper, we report results on two-colour above-threshold ionisation, where extreme ultraviolet pulses of femtosecond duration were synchronised to intense infrared laser pulses of picosecond duration, in order to study the laser-assisted photoelectric effect of atomic helium, neon, krypton and xenon which leads to the appearance of characteristic sidebands in the photoelectron spectra. The observed trends are found to be well described by a simple model based on the soft-photon approximation, at least for the relatively low optical intensities of up to ? employed in these early experiments.

  19. Measurements of line-averaged electron density of pulsed plasmas using a He-Ne laser interferometer in a magnetized coaxial plasma gun device

    Science.gov (United States)

    Iwamoto, D.; Sakuma, I.; Kitagawa, Y.; Kikuchi, Y.; Fukumoto, N.; Nagata, M.

    2012-10-01

    In next step of fusion devices such as ITER, lifetime of plasma-facing materials (PFMs) is strongly affected by transient heat and particle loads during type I edge localized modes (ELMs) and disruption. To clarify damage characteristics of the PFMs, transient heat and particle loads have been simulated by using a plasma gun device. We have performed simulation experiments by using a magnetized coaxial plasma gun (MCPG) device at University of Hyogo. The line-averaged electron density measured by a He-Ne interferometer is 2x10^21 m-3 in a drift tube. The plasma velocity measured by a time of flight technique and ion Doppler spectrometer was 70 km/s, corresponding to the ion energy of 100 eV for helium. Thus, the ion flux density is 1.4x10^26 m-2s-1. On the other hand, the MCPG is connected to a target chamber for material irradiation experiments. It is important to measure plasma parameters in front of target materials in the target chamber. In particular, a vapor cloud layer in front of the target material produced by the pulsed plasma irradiation has to be characterized in order to understand surface damage of PFMs under ELM-like plasma bombardment. In the conference, preliminary results of application of the He-Ne laser interferometer for the above experiment will be shown.

  20. Determination of total polyphenolic content in red wines by means of the combined He-Ne laser optothermal window and Folin-Ciocalteu colorimetry assay.

    Science.gov (United States)

    Dóka, Ottó; Bicanic, Dane

    2002-05-01

    The He-Ne laser (632.8 nm) and the concept of optothermal window (OW), a variant of the open photoacoustic cell, were combined with the Folin-Ciocalteu colorimetry assay to quantitate phenolics in four red wines. The total polyphenolic content in selected red wines varied between 786 and 1630 mg/L gallic acid equivalent (GAE) as determined by OW-Folin-Ciocalteu colorimetry, which compares well to 778 and 1614 mg/L GAE obtained for the same wines by means of classical spectrophotometry. The originality and merit of OW colorimetry used here is that, unlike what is encountered in conventional spectrometry, no intermediate dilution step is required when total polyhenolics are determined in red wine. The precision, defined as the closeness to each other of 256 replicate readings of the OW signal, is generally better than 2%.

  1. Analysis of the collagen birefringence and the relative attenuation coefficient of health and burned skin irradiated with linearly polarized He-Ne laser; Analise da birrefringencia do colageno e do coeficiente de atenuacao de amostras de pele sadia e queimada irradiadas pelo laser de He-Ne linearmente polarizado

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Daniela de Fatima Teixeira da

    2002-07-01

    Low-intensity laser therapy is characterized by its ability to induce athermic effects and nondestructive photobiological processes. Although it has been in use for more than 40 years, this phototherapy is still not an established therapeutic modality. The objectives of this study were: to quantify the collagen fibers organization by polarized light microscopy in normal and burned skin samples at day 17 post-injury considering preferential axis as the animal's spinal column and aligning the linear laser polarization in two directions of polarization, parallel or perpendicular to this axis; to determine the relative attenuation coefficient for the intensity light by the technique of imaging the light distribution in normal and burned skin during wound healing process taking only parallel direction of polarization. To reach the objectives, burns about 6 mm in diameter were created with liquid N{sub 2} on the back of the rats and the lesions were irradiated on days 3, 7, 10 and 14 post-wounding, D= 1 J/cm{sup 2}, to investigate the effects of low-intensity linearly polarized He-Ne laser beam on skin wounds healing. Control lesions were not irradiated. The results have demonstrated that: the skin samples irradiated with linearly parallel polarized He-Ne laser beam showed collagen fibers more organized; burned skin samples presents a higher attenuation coefficient than normal skin samples. These results are important to optimize low intensity laser therapy dosimetry on acceleration wound healing. (author)

  2. 氦-氖激光照射治疗颈部瘢痕疙瘩性毛囊炎%Treatment of folliculitis keloidnlis nuchae with He-Ne Laser

    Institute of Scientific and Technical Information of China (English)

    宋雪英; 卜亚云

    2003-01-01

    AIM: To verify curative effect of He-Ne laser on folliculitis keloidalisnuchae. METHODS: 103 cases with folliculitis keloicdalis nuchae were di-vided into the treatment group(73 cases) and the control group(30 eases).Local application and oral antiauxins was used in the two groups, He-Ne laserradiation was used in the treatment group and then curative effect 15 dayslater were compared. RESULTS: The cure rats in the treatment group andcontrol group were respectively 71.2% (52/73) and 30% (9/30) (P <0.01 ) while curative days were respectively 9. 2 days and 11.9 days ( P <0.01 ) . CONCLUSION: In treatment of folliculitis Keloidalis nuchae, theapplication of He-Ne Laser radiation can effectively recduce the course, painand side-effect of treatment, and raise the curative effect.

  3. He-Ne laser effects on blood microcirculation. An in vivo study through laser doppler flowmetry; Efeito do laser de helio neonio sobre a microcirculacao sanguinea durante a reparacao tecidual. Estudo in vivo por meio de fluxometria laser doppler

    Energy Technology Data Exchange (ETDEWEB)

    Nunez, Silvia Cristina

    2002-07-01

    Blood microcirculation performs an important function in tissue repair process, as well as in pain control, allowing for greater oxygenation of the tissues and the accelerated expulsion of metabolic products, that may be contributing to pain. Low Intensity Laser Therapy (LILT) is widely used to promote healing, and there is an assumption that it is mechanism of action may be due to an enhancement of blood supply. The purpose of this study was to evaluate, using laser Doppler flowmetry (LDF), the stated effects caused by radiation emitted by a He-Ne laser ({lambda}=632.8 nm) on blood microcirculation during tissue repair. To this end, 15 male mice were selected and received a liquid nitrogen provoked lesion, above the dorsal region, and blood flow was measured periodically, during 21 days. Due to radiation emission by the LDF equipment, a control group was established to evaluate possible effects caused by this radiation on microcirculation. To evaluate the He-Ne laser effects, a 1.15 J/cm{sup 2} dose was utilized, with an intensity of 6 mW/cm{sup 2}. The results obtained demonstrate flow alterations, provoked by the lesion, and subsequent inflammatory response. There was no statistical difference between the studied groups. As per the analysis of the results there is no immediate effect due the radiation emitted by a He Ne laser on microcirculation, although a percentage increase was observed in day 7 on medium blood flow rate in irradiated specimens. New studies are necessary to validate the use of this wavelength, in order to promote beneficial alterations in blood supply in radiated areas. (author)

  4. Efficacy of multiple exposure with low level He-Ne laser dose on acute wound healing: a pre-clinical study

    Science.gov (United States)

    Prabhu, Vijendra; Rao, Bola Sadashiva S.; Mahato, Krishna Kishore

    2014-02-01

    Investigations on the use of Low Level Laser Therapy (LLLT) for wound healing especially with the red laser light have demonstrated its pro-healing potential on a variety of pre-clinical and surgical wounds. However, until now, in LLLT the effect of multiple exposure of low dose laser irradiation on acute wound healing on well-designed pre-clinical model is not much explored. The present study aimed to investigate the effect of multiple exposure of low dose Helium Neon laser on healing progression of full thickness excision wounds in Swiss albino mice. Further, the efficacy of the multiple exposure of low dose laser irradiation was compared with the single exposure of optimum dose. Full thickness excision wounds (circular) of 15 mm diameter were created, and subsequently illuminated with the multiple exposures (1, 2, 3, 4 and 5 exposure/ week until healing) of He-Ne (632.8 nm, 4.02 mWcm-2) laser at 0.5 Jcm-2 along with single exposure of optimum laser dose (2 J/cm-2) and un-illuminated controls. Classical biophysical parameters such as contraction kinetics, area under the curve and the mean healing time were documented as the assessment parameters to examine the efficacy of multiple exposures with low level laser dose. Experimental findings substantiated that either single or multiple exposures of 0.5 J/cm2 failed to produce any detectable alterations on wound contraction, area under the curve and mean healing time compared to single exposure of optimum dose (2 Jcm-2) and un-illuminated controls. Single exposure of optimum, laser dose was found to be ideal for acute wound healing.

  5. Improvement of the antifungal activity of Litsea cubeba vapor by using a helium-neon (He-Ne) laser against Aspergillus flavus on brown rice snack bars.

    Science.gov (United States)

    Suhem, Kitiya; Matan, Narumol; Matan, Nirundorn; Danworaphong, Sorasak; Aewsiri, Tanong

    2015-12-23

    The aim of this study was to improve the antifungal activity of the volatile Litsea cubeba essential oil and its main components (citral and limonene) on brown rice snack bars by applying He-Ne laser treatment. Different volumes (50-200 μL) of L. cubeba, citral or limonene were absorbed into a filter paper and placed inside an oven (18 L). Ten brown rice snack bars (2 cm wide × 4 cm long × 0.5 cm deep) were put in an oven and heated at 180 °C for 20 min. The shelf-life of the treated snack bars at 30 °C was assessed and sensory testing was carried out to investigate their consumer acceptability. A count of total phenolic content (TPC) and Fourier transform infrared spectroscopy (FTIR) on the properties of essential oil, citral, and limonene before and after the laser treatment was studied for possible modes of action. It was found that the laser treatment improved the antifungal activity of the examined volatile L. cubeba and citral with Aspergillus flavus inhibition by 80% in comparison with those of the control not treated with the laser. L. cubeba vapor at 100 μL with the laser treatment was found to completely inhibit the growth of natural molds on the snack bars for at least 25 days; however, without essential oil vapor and laser treatment, naturally contaminating mold was observed in 3 days. Results from the sensory tests showed that the panelists were unable to detect flavor and aroma differences between essential oil treatment and the control. Laser treatment caused an increase in TPC of citral oil whereas the TPC in limonene showed a decrease after the laser treatment. These situations could result from the changing peak of the aliphatic hydrocarbons that was revealed by the FTIR spectra.

  6. Effect of He-Ne Laser and CO2 Laser on Bone Fracture Healing%He-Ne激光与扩束CO2激光照射对骨折愈合的影响

    Institute of Scientific and Technical Information of China (English)

    崔建胜; 章萍

    2011-01-01

    目的 比较相同剂量的He-Ne激光与CO激光照射对骨折的疗效.方法 36只健康雄性兔制成骨折模型,随机分为三组,每组12只.He-Ne激光组:He-Ne激光扩束照射骨折区;CO激光组:CO激光扩束照射骨折组;对照组:常规治疗.通过X片,观察骨折愈合情况,测定骨痂中钙和胶原含量及生物力学抗扭性能,比较三组的疗效.结果 (1)骨折愈合效果:两激光组均优于对照组(P激光组优于He-Ne激光组(P激光组好于He-Ne激光组(P)和瞬间扭矩(T)均高于对照组(P激光组T高于He-Ne激光组.结论 He-Ne激光与CO激光照射对骨折愈合均有促进作用,且CO激光更好于He-Ne激光.%Objective To obsere and compare the discrepancy of curative effect of He-Ne laser and CO2 laser irradiation under the same dosage.Methods The bone fracture pattern was made to 36 healthy male rabbits, who were randomly divided into 3 groups ( each 12) : He-Ne laser group: expanding a bunch of the He-Ne laser project light upon the bone fracture zone, CO2 laser group: expanding a bunch of the CO2 laser irradiation, and matched control group:the routine cures.The different therapy impact was observed on the bone fracture healing.Observed X-ray, detected the contents of collagen and calcium in the callus, and measured the biomechanics anti-torsion strength to evaluate curative effect.Results ( 1 ) Fracture healing effect: the two laser groups were better than the control group (P <0.05 or <0.01 ), and 25 days after treatment, CO2 laser group was better than He-Ne laser group ( P < 0.04 ).(2) Collagen and calcium content: two laser groups were higher than control group (P < 0.05), and CO2 laser group was better than He-Ne laser group ( P < 0.05 ).(3) Biomechanics anti-torsion strength: the minimum torque ( T8°) and instantaneous torque (Tmax) of both laser groups were higher than that of control group (P <0.01 ), and the Tmax of CO2 laser group was higher than that of He-Ne laser group

  7. 大功率氦氖激光治疗增生性瘢痕的实验研究%Research of irradiation of high-power He-Ne laser on hypertrophic scar in rabbits

    Institute of Scientific and Technical Information of China (English)

    舒彬; 郝林林; 吴宗耀; 黄显凯; 袁纯; 唐其敏

    2002-01-01

    Objective To explore the therapeutic effects and mechanisms of high power He Ne laser irradiation on hypertrophic scar(HS) in rabbits by setting up hypertrophic scar animal model.Methods 32 round wounds(diameter of 6 mm) and skin layer loss were made on ventral side of rabbits' ears using a trephine.21 days after the operation,10 projecting scars were irradiated with He Ne laser for 30 minutes every other day,for two weeks.Another 10 projecting scars were as control group.35 days later,cell apoptosis rate and PCNA protein expression of the scar histology were measured by TUNEL technique and immunohistochemistry method,respectively.Results In He Ne laser group,scars became much thinner than those in control group(P< 0.05).Cell apoptosis rate increased greatly while PCNA protein expression decreased a lot.There were significant difference between the two groups(both P < 0.05).Conclusion It shows that high power He Ne laser could inhibit the growth of HS in rabbits by inducing cell apoptosis and inhibiting cell proliferation probable.

  8. Kinetic model of a Penning Ne-laser with He-Ne-Ar and Ne-H2 beam plasma

    Energy Technology Data Exchange (ETDEWEB)

    Derzhiev, V.I.; Zhidkov, A.G.; Koval' , A.V.; Iakovlenko, S.I. (Institut Obshchei Fiziki, Moscow (USSR))

    1989-08-01

    A kinetic model of a Penning Ne-laser laser with Ne-He-Ar and Ne-H2 mixtures pumped by an electron beam is developed. Plasma parameters and characteristics of the Ne yellow line emission (585.3 nm) are calculated for both quasi-steady-state and nonsteady-state pumping. Theoretical results agree well with experimental data on lasing for a wide range of durations and densities of the pump current, and mixture pressures and compositions. 13 refs.

  9. 632 nm氦-氖激光治疗智齿冠周炎的研究%Study on 632 nm He-Ne laser therapy on pericoronitis

    Institute of Scientific and Technical Information of China (English)

    韦界飞; 邹群

    2013-01-01

    目的 通过临床试验,验证632 nm氦-氖红色激光对智齿冠周炎的镇痛效果和临床疗效.方法 选择下颌第3磨牙冠周炎患者75例,随机分为实验组和对照组.2组均采用局部常规治疗后,实验组用氦-氖激光局部照射15 min/d;对照组不再采取其他治疗.治疗后3、7d采用疼痛3度记分法记录消炎镇痛情况,并对2种治疗方法的效果进行综合评价.结果 治疗后3d,实验组78.9%患者疼痛消失,对照组51.4%患者疼痛消失;治疗后7d,实验组97.4%的患者疼痛消失,对照组91.9%的患者疼痛消失.治疗后3、7d,2组间疗效对比差异有统计学意义(P<0.05).结论 氦-氖激光在治疗智齿冠周炎上具有明显的消炎镇痛效果.%Objective To investigate the effects of He-Ne laser on the treatment of pericoronitis.Methods 75 clinical patients with pericoronitis were randomly divided into the experimental group and control group.Local conventional therapy was given to the two groups.The experimental group was given routine treatment with He-Ne laser local exposure for 15 minutes every day,while the control group took no other treatment.3 days and 7 days later,pain and inflammation degree were recorded by three-degree pain scoring method.Total treatment effects were evaluated under a comprehensive clinical treatment standard.Results After 3 days' treatment,78.9% patients in the experimental group and 51.4% patients in control group felt their pain disappeared.After 7 days' treatment,97.4% patients in experimental group and 91.9% patients in control group felt their pain disappeared.Treatment comprehensive evaluation showed that there were statistical significance differences between two groups (P<0.05).Conclusion He-Ne laser treatment of pericoronitis has significant anti-inflammatory analgesic effect.

  10. Precision Controlling of Frequency Difference for Elastic-Stress Birefringence He-Ne Dual-Frequency Lasers

    Institute of Scientific and Technical Information of China (English)

    ZHOU Lu-Fei; ZHANG Shu-Lian; GUO Hong; REN Zhou

    2007-01-01

    Birefringence-Zeeman dual frequency lasers are capable of producing frequency difference from several kilohertz to hundreds of megahertz, but the precision of giving and stabilizing of the beat frequency still needs improvement to the range of ±200 kHz. We design a new elastic force-exerting device comprised of the bottom part, two arms and two pieces of force-exerting sheets. The frequency difference smoothly tuning is realized with this device in a large range of 2 MHz to 20 MHz. Power-balance frequency stabilization system is used to investigate characters of the temperature, frequency difference and laser power. The precision of the frequency difference has reach up to JrlOO kHz after system temperature balance. Analyses of the laser frequency difference and power character are carried out.

  11. Influence of intravascular low level He-Ne laser irradiation on iNOS, total-NOS, and ET-1 in acute spinal cord-injured rabbits

    Science.gov (United States)

    Yin, Zhenchun; Dong, Yinghai; Zhu, Jing

    2005-07-01

    Objective To research the influence of intravascular low level Laser irradiation (ILLLI) on total NOS, iNOS, and ET-1 in spinal cord following acute spinal cord injury (ASCI), and discuss the protective effects of ILLLI on neurons .Methods 72 rabbits were randomly divided into 3 groups: treatment group, injury group and control group. In treatment group and injury group, after laminectomy at the level of T-13, ASCI was performed by using Allen"s method with slight modification (6g×10cm) on rabbits. After injury, rabbits were treated immediately with He-Ne laser (power 5 mW, 1 hour per day for 10 days). At the day of 10th after treatment, total-NOS, iNOS, and ET-1 in spinal cord tissues were measured. Results The expression level of total-NOS, iNOS, and ET-1 in spinal cord in injury group were significantly higher than those in control group (Pspinal cord. It indicates that ILLLI can relieve the overexpression of total-NOS, iNOS, and ET-1 ,and thus can perform protective effects on neurons in the course of secondary spinal cord injury (SSCI) following ASCI

  12. Determination of lactose in raw milks by means of the combined He-Ne laser optothermal window

    NARCIS (Netherlands)

    Bakos, P.; Doka, O.; Ajtony, Z.; Bicanic, D.; Szucs, D.

    2002-01-01

    The concept of OW (with 632.8 nm He–Ne laser), combined with colorimetry based on a reaction of anthrone-sulphuric acid, was proposed as a new tool for determination of lactose in raw milk. Data obtained from various milk samples by OW colorimetry were compared to those acquired from the MilkoScan a

  13. Influence of He-Ne laser irradiation of soybean seeds on seed mycoflora, growth, nodulation, and resistance to Fusarium solani.

    Science.gov (United States)

    Ouf, S A; abdel-Hady, N F

    1999-01-01

    Laser irradiation of soybean seeds for 3 min caused a clear reduction in the number of seed-borne fungi which became more pronounced as the irradiation time was extended. Pretreatment of the seeds with methylene blue, methyl red and carmine enhanced the effect of laser. Rhizoctonia solani, Alternaria tenuissima, Cercospora kikuchii and Colletotrichum truncatum were completely eliminated when the seeds were pretreated with a dye and irradiated for 10 min. Seed germination was stimulated on exposure of the seed to 1-min irradiation. At such dose, most of the dyes were accelerators while the higher doses were inhibitory to seed germination. Chlorophyll a, chlorophyll b and carotenoid content of developed plants differed, depending on the irradiation dose and dye treatment of the seeds. In seeds irradiated for 1 or 3 min, chlorophyll a formation was less affected than chlorophyll b formation. In seeds irradiated for 10 min, both the chlorophyll contents were decreased especially in the presence of some applied dyes. On the other hand, there was an increase in carotenoid content of soybean leaves when the laser dose increased. The number and dry mass of nodules were mostly greater (as compared to the corresponding control), when the seeds irradiated for 1 or 3 min were pretreated with methyl red, chlorophenol red, crystal violet and methylene blue. Irradiation of pre-sowing seeds greatly protected soybean stands against F. solani. The disease incidence differed somewhat when the irradiated seeds were pretreated with dyes. The reduction in disease incidence was accompanied by accumulation of high proline and phenol levels in the infected root tissues of soybean, suggesting that these compounds have a certain role in the prevention of disease development.

  14. Treatment of relapse in herpes simplex on labial and facial areas and of primary herpes simplex on genital areas and "area pudenda" with low-power He-Ne laser or Acyclovir administered orally

    Science.gov (United States)

    Velez-Gonzalez, Mariano; Urrea-Arbelaez, Alejandro; Nicolas, M.; Serra-Baldrich, E.; Perez, J. L.; Pavesi, M.; Camarasa, J. M.; Trelles, Mario A.

    1996-01-01

    Sixty patients (greater than 16 yrs old) suffering primary or relapse genital herpes simplex viruses (HSV) and relapse labial HSV were appointed for this study. Three or more relapses were experienced per year. Patients (under treatment) were divided into two groups (distribution areas), corresponding to either labial herpes or genital herpes. These groups were sub-divided into 3 groups. The total number of labial or facial HSV patients was 36 (10 in group 1, 12 in group 2, 14 in group 3) and 24 for genital, buttocks, or 'area pudenda' HSV patients (6 in group 1, 8 in group 2, 10 in group 3). The design was a randomized, double- blind study. The setting was hospital and outpatient. The patients diagnosed as having the HVS disease were sent to the dermatology department and were assigned to a group at random. Treatment was begun as follows: During the treatment signs and symptoms were assessed and after the treatment, the relapses were also assessed (biochemical and hematological tests before and after the treatment) and the diagnosis of the HSV type I and II. The statistical evaluation of the results was performed and carried out with the SPSS and BMDP program. The relapses of the herpes infection in the lips and the face were significantly reduced (p less than 0.026) in patients treated with laser He-Ne and laser He-Ne plus Acyclovir. The interim between the relapses also increased significantly (p less than 0.005) in relation with the group treated with Acyclovir. The duration of the herpetic eruptions was clearly reduced in all locations in patients treated with laser He-Ne plus Acyclovir. No differences were noted between patients treated with laser He-Ne only or Acyclovir only. Therefore it is probable that therapeutic synergism took place. In relation with this, laser He-Ne shows the same therapeutic efficacy as Acyclovir taken orally. The association of Acyclovir and laser Ne-Ne could be an alternative method for the treatment of HSV in the face. The number

  15. Rotationally inelastic scattering in CH4+He, Ne, and Ar: State-to-state cross sections via direct infrared laser absorption in crossed supersonic jets

    Science.gov (United States)

    Chapman, William B.; Schiffman, Aram; Hutson, Jeremy M.; Nesbitt, David J.

    1996-09-01

    Absolute integral state-to-state cross sections are reported for rotationally inelastic scattering in crossed jets of CH4 with the rare gases He, Ne, Ar, at center of mass collision energies of 460±90, 350±70, and 300±60 cm-1, respectively. CH4 seeded in Ar buffer gas is cooled in a pulsed supersonic expansion into the three lowest rotational levels allowed by nuclear spin statistics corresponding to A(J=0), F(J=1), and E(J=2) symmetry. Rotational excitation occurs in single collisions with rare gas atoms from a second pulsed supersonic jet. The column integrated densities of CH4 in both initial and final scattering states are subsequently probed in the jet intersection region via direct absorption of light from a narrow bandwidth (0.0001 cm-1), single mode color center laser. Total inelastic cross sections for collisional loss out of the J=0, 1, and 2 methane states are determined in absolute units from the linear decrease of infrared absorption signals as a function of collider gas concentration. Tuning of the ir laser source also permits probing of the collisionally excited rotational states with quantum state and velocity resolution; column integrated scattering densities are measured for all energetically accessible final states and used to infer absolute inelastic cross sections for state-to-state energy transfer. The observed trends are in good qualitative agreement with quantum state resolved pressure broadening studies; however, the dependences of the rotationally inelastic cross sections on nuclear spin modification (i.e., J) and rotational inelasticity (i.e., ΔJ) is not well predicted by conventional angular momentum or energy gap models. More rigorous comparison with the quantum state-resolved scattering data is obtained from full close coupled scattering calculations on trial potential energy surfaces by Buck and co-workers [Chem. Phys. Lett. 98, 199 (1983); Mol. Phys. 55, 1233, 1255 (1985)] for each of the three CH4+rare gas systems. Agreement

  16. Clinical and radiographic investigation of the adjunctive effects of a low-power He-Ne laser in the treatment of moderate to advanced periodontal disease: a pilot study.

    Science.gov (United States)

    Lai, S M L; Zee, K-Y; Lai, M K; Corbet, E F

    2009-04-01

    To evaluate the adjunctive effect of a low-power He-Ne laser in the non-surgical periodontal treatment of patients with moderate to advanced chronic periodontitis. Laser applications in dental treatment are now more common in the literature. However, limited data are available on the potential effects of the low-power laser as an adjunct to non-surgical periodontal therapy for managing patients with moderate to advanced periodontal disease. Sixteen patients with probing pocket depth (PPD) > or =5 mm and comparable bone defects on both sides of the mouth were recruited. Supragingival plaque (PL), bleeding on probing (BOP), PPD, and probing attachment level (PAL) were recorded at baseline and at 3, 6, 9, and 12 mo, while gingival crevicular fluid (GCF) samples and standardized intra-oral radiographs for digital subtraction radiography were taken at baseline and at 1, 3, 6, 9, and 12 mo. After non-surgical mechanical periodontal treatment, the test sites were selected randomly and irradiated with a low-power He-Ne laser (output power 0.2 mW) for 10 min for a total of eight times in the first 3-mo period, while the control sites received no additional treatment. PL percentage (83-16%) and BOP percentage (95-34%) decreased significantly after 12 mo. Statistically significant changes in reductions of PPD and GCF volume, gain in PAL, and increase in recession were seen in both test and control sites when compared to baseline (p low-power He-Ne laser as an adjunct to non-surgical periodontal therapy in patients with moderate to advanced chronic periodontitis did not seem to provide additional clinical benefit.

  17. Efficacy Observation on He-Ne Laser Physiotherapy Treating Traumatic Perforation of Tympanic Membrane%氦氖激光理疗治疗外伤性鼓膜穿孔疗效观察

    Institute of Scientific and Technical Information of China (English)

    杨景; 李金凤

    2013-01-01

    Objective:To observe the curative effects of He-Ne laser physiotherapy treating traumatic perforation of tympanic membrane. Methods:60 cases were randomly divided into observation group and control group, control group with natural healing, observation group were treated with He-Ne laser physiotherapy, the closure time and closure rate of perforation and infection between two groups were observed. Results:Closure time of perforation in observation group, with higher closure rate and lower infection rate, was less than that in control group (P<0.01). Conclusion:He-Ne laser physiotherapy treating traumatic perforation of tympanic membrane can promote the wound healing, with ideal clinical efficacy, which is wor-thy of popularization and application.%  目的:观察氦氖激光理疗治疗外伤性鼓膜穿孔的疗效。方法:60例患者随机分为观察组和对照组,对照组采用自然愈合,观察组应用氦氖激光理疗,观察两组患者的穿孔闭合时间、穿孔闭合率及感染情况。结果:观察组穿孔闭合时间少于对照组,闭合率高于对照组,感染率低于对照组(P<0.01)。结论:氦氖激光理疗治疗外伤性鼓膜穿孔可促进伤口愈合,临床疗效理想,值得推广应用。

  18. A comparative study on non-confluent and confluent human malignant brain cancer metabolic response to He-Ne laser exposures: evidence for laser enhanced cellular production of H2O2 and laser induced bystander effect

    Science.gov (United States)

    Tata, Darrell B.; Waynant, Ronald W.

    2009-02-01

    Continuous wave He-Ne laser exposures (Intensity = 35 mW/cm2, λ=632.8nm, Fluence range: 1J/cm2 to 50 J/cm2) on non-confluent and fully confluent human malignant glioblastoma cells was found to increase the cellular production levels of H2O2. Modulations in the cellular metabolic activity were detected (through the MTS assay) three days after the laser irradiation. The metabolic activity was found to be dependent on the laser fluence for both cell growth conditions. Furthermore, three days after the laser exposure, the potential laser induced "bystander" effect was tested through the transfer of growth media from laser irradiated cells onto non-irradiated cells. After two additional days of incubation (5 days post exposure), the non-laser irradiated cells grown under the non-confluent condition were found to have a significant increase in their metabolic activities, whereas minimal to null response was found for the fully confluent condition. For cells grown under the non-confluent conditions, modulations in the metabolic activities in the non-irradiated cells were found to be laser fluence dependent from the initial laser exposed cells treatment conditions. The results herein support the hypothesis of an important role for light enhanced cellular H2O2 generation to yield bio-modulatory effects locally and at a distance. The classical "bi-phasic" modulation response of cells to light irradiation is hypothesized to depend upon the quantity of light enhanced H2O2 molecules generated from the mitochondria and the number of cells which interact with the H2O2 molecules.

  19. 低功率氦氖激光在儿童弱视治疗中的应用%Low power He-Ne laser in the treatment of amblyopia in children

    Institute of Scientific and Technical Information of China (English)

    杨小梅; 师文; 左芸; 杨发斌

    2011-01-01

    Objective To study the effects of low power He-Ne laser in the treatment of amblyopia in children. Methods The low power He-Ne laser with joint integrated therapy in treating 86 cases of 146 amblyopic eyes. The low power He-Ne laser irradiated the amblyopic eyes 3 minutes per day, continuous treatment of 20 days, to observe the effect. Results The low power He-Ne laser with joint integrated therapy in the treatment of amblyopia in children, the basic cure rate was 50.68%, effective (cure + improvement) rate was 85.62%. Amblyopia in the 3 to 6 age group has the best effect (77/83), the refractive amblyopia in different types of amblyopia has the best effect (93/104), the mid amblyopia in different degrees of amblyopia has the best effect (87/105), the center concave watching in different watching natures of amblyopia has the best effect (80/86), the near vision of 1.0 in different near vision amblyopia has the best effect (109/ 126). Conclusions Low power He-Ne laser can shorten the course of treatment of amblyopia, improve compliance in amblyopia children and parents, is effective in treating amblyopia.%目的 观察低功率氦氖激光在儿童弱视中的治疗作用方法对86例146只弱视眼采用低功率氦氖激光联合综合疗法进行治疗,激光每日照射弱视眼3min,连续治疗20d,观察疗效.结果 低功率氦氖激光联合综合疗法治疗儿童弱视,基本治愈率为50.68%,有效率85.62%.其中不同年龄弱视中以3-6岁组疗效最好(77/83),不同类型弱视中以屈光不正性弱视疗效最好(93/104),不同程度弱视以轻度弱视疗效最好(87/105),不同注视性质弱视以中心凹注视疗效最好(80/86),不同近视力弱视以近视力为1.0疗效最好(109/126).结论 低功率氦氖激光可缩短弱视治疗的疗程,提高弱视患儿和家长的依从性,对儿童弱视的治疗有效.

  20. Optically pumped laser lines of Na2 pumped by Kr/+/ /6471 A/ and HeNe /6328 A/ lasers - Identification of old lines and prediction of possible new lines

    Science.gov (United States)

    Verma, K. K.; Stwalley, W. C.; Zemke, W. T.

    1981-01-01

    The laser emission lines of a sodium dimer laser pumped by Kr(+) and HeNe lasers at wavelengths of 6471 and 6328 A, respectively, are identified. The Na2 fluorescence was excited in a crossed heat pipe oven at a sodium pressure of about 1 torr, and recorded spectra were compared with transition probability calculations. For the 6471-A pump, three series excited by absorption through the transitions v-prime = 13, J-prime = 35 - v-double prime = 4, J-double prime = 34; v-prime = 13, J-prime = 83 - v-double-prime = 2, J-double prime = 84 and v-prime = 20, J-prime = 98 - v-double prime = 6, J-double prime = 99 are observed in the region 6100-8350 A. At 6328 A, series excited through the transitions v-prime = 14, J-prime = 45 - v-double prime = 2, J-double prime = 46; v-prime = 16, J-prime = 17 - v-double prime = 4, J-double prime = 18; v-prime = 22, J-prime = 86 - v-double prime = 6, J-double prime = 85 and v-prime = 25, J-prime = 87 - v-double prime = 8, J-double prime = 86. Most of the previously observed optically pumped lines are found to correspond to the three level laser system. Additional wavelengths expected to undergo lasing under slightly improved conditions are also identified.

  1. Scattering and Absorbing Characteristics of Human Arteries and Veins in Kubelka-Munk Model at He-Ne Laser in Vitro%Kubelka-Munk模型下人血管对He-Ne激光的散射与吸收特性

    Institute of Scientific and Technical Information of China (English)

    魏华江; 李晓原; 巫国勇; 刘小星; 魏冬季; 谭润初

    2001-01-01

    The diffuse reflectance and transmittance of human arteries and veins were studied with 632.8 nm of He-Ne laser. The measurements were performed with two standard integrating sphere systems. The absorption coefficient, scattering coefficient and the changes of total optical intensities I(x), forward scattering flux i(x), backward scattering flux j(x) as a function of thickness of human arteries and veins were evaluated and analyzed from the experimented data by Kubelka-Munk model. The results of measurement showed significant difference of diffuse reflectance and transmittance between arteries and veins at 632.8 nm wavelength of He-Ne laser. Furthermore, the absorption coefficient and the scattering coefficient of arteries were obviously bigger than that of veins at He-Ne laser wavelength. The changes of I(x), i(x) and j(x) as a function of thickness of human arteries and veins were also significant difference.%测量了人动脉和静脉对He-Ne激光的反射和透射传输特性.实验采用两积分球系统及波长为632.8 nm的He-Ne激光器,并根据测量数据及采用Kubelka-Munk模型分析和计算了人动脉和静脉组织对该波长激光的吸收系数、散射系数及总的光强I(x)及前向散射通量i(x)和后向散射通量j(x)随厚度的变化情况.结果表明,人动脉和静脉的漫反射率和透射率有明显差别,而且,动脉对激光的吸收系数和散射系数明显较静脉的大,在动脉和静脉组织中I(x),i(x)和j(x)随厚度的变化情况也有明显的区别.

  2. Microbunching of relativistic electrons using a two-frequency laser

    Science.gov (United States)

    Gordon, D.; Clayton, C. E.; Katsouleas, T.; Mori, W. B.; Joshi, C.

    1998-01-01

    A high power two-frequency laser can be used to modulate the axial momentum of a copropagating relativistic electron beam. The net work done on each electron is accounted for almost entirely by the axial electric field of the laser even when approaching the one-dimensional limit. After interacting with the laser, the electron beam can be bunched either by a long drift space or a dispersive optic. We give an example in which a 2.5-TW CO2 laser and a chicane compressor are used to transform a constant stream of 16-MeV electrons into a train of 60-fs microbunches, each containing 10 pC of charge.

  3. Clinical Observation on Diabetic Foot Treated by He-Ne Laser Radiation Together with Jiawei-Taohong-Siwu Soup%氦氖激光配合加味桃红四物汤治疗糖尿病足临床观察

    Institute of Scientific and Technical Information of China (English)

    吕蕾; 刘志勤

    2003-01-01

    Objective: To observe treatment effect on Diabetic Foot 0 period treated by intravenous He-Ne laser Radiation together with Jiawei-Taohong-Siwu Soup. Methods: 84 cases with Diabetic Foot 0 were divided into two groups,one was Treatment group with 62 patients, the other was comparison group with 22 patients. Two group were treated. The treatment group were treated by He-Ne Laser Radiation together with Jiawei-Taohong-Siwu Soup, The comparison group were treated by common Danshen transfusion. To observe clinical symptom and blood rheology before and after treatment,Results:Both of two group have improved, but treatment group was better than comparison group. To compare with the latter, Their whole blood rate viscosity, plasma rate viscosity, etc. were obviously decreased and had significant difference.Conclusion:It has remarkable curative effect for intravenous He-Ne Laser Radiation together with Jiawei-Taohong-Siwu soup to treat Diabetic Foot 0 neriod.

  4. Comparison of HeNe laser and sinusoidal non-uniform magnetic field seed pre-sowing treatment effect on Glycine max (Var 90-I) germination, growth and yield.

    Science.gov (United States)

    Asghar, Tehseen; Iqbal, Munawar; Jamil, Yasir; Zia-Ul-Haq; Nisar, Jan; Shahid, Muhammad

    2017-01-01

    Recently, laser and magnetic field pre-sowing seed treatments attracted the attention of the scientific community in response to their positive effect on plant characteristics and the present study was exemplified for Glycine max Var 90-I. Seeds were exposed to laser (HeNe-wave length 632nm and density power of 1mW/cm(2)) and magnetic field (sinusoidal non-uniform-50, 75 and 100mT for 3, 5min with exposure) and seed germination, seedling growth and yield attributes were compared. The germination (mean germination, germination percentage, emergence index, germination speed, relative germination coefficient, emergence coefficient of uniformity) growth (root dry weight, root length, shoot fresh weight and shoot dry weight, leaf dry & fresh weight, root fresh weight, leaf area, shoot length, plant total dry weight at different stages, stem diameter, number of leaves, vigor index I & II), biochemical (essential oil) and yield attributes (seed weight, count) were enhanced significantly in response to both laser and magnetic field treatments. However, magnetic field treatment furnished slightly higher response versus laser except relative water contents, whole plant weight and shoot length. Results revealed that both laser and magnetic field pre-sowing seed treatments affect the germination, seedling growth, and yield characteristics positively and could possibly be used to enhance Glycine max productivity. Copyright © 2016 Elsevier B.V. All rights reserved.

  5. Re-cognition of Knife-edge Method Measuring of He-Ne Laser Beam Divergence Angle%刀口法测量He-Ne激光束发散角实验的再认识

    Institute of Scientific and Technical Information of China (English)

    魏奶萍; 张相武

    2015-01-01

    The method of edge of He-Ne laser beam divergence angle measurement principle is proved in theo-ry,and then according to the relative power of 0. 25 and 0. 75 points in laser Gaussian distribution curve on both sides of the maximum. The data measured in the experiment are processed by curve fitting,the laser beam divergence angle is obtained.%对刀口法测量He-Ne激光束发散角的测量原理从理论上进行了证明,然后根据激光束相对功率为0.25和0.75的点位于高斯分布曲线极大值两侧,距离为ep =0.6745σ=0.3373W ,对测量实验数据进行曲线拟合,求得其激光光束发散角。

  6. Observation on the curative effect of He-ne laser combined with ganciclovir on shingles%氦氖激光联合更昔洛韦治疗带状疱疹的疗效观察

    Institute of Scientific and Technical Information of China (English)

    李敏; 邱宇芬; 易恒安; 叶冬晴

    2014-01-01

    目的:探讨氦氖激光联合更昔洛韦治疗带状疱疹的临床疗效。方法:选择86例带状疱疹患者随机分为对照组和观察组两组,分别43例,对照组患者使用更昔洛韦0.25 g,1次/ d 静脉注射治疗;观察组患者在对照组治疗的基础上联合使用氦氖激光于疼痛部位及皮损处直接照射10 min,1次/ d,两组均连续治疗7 d,对两组治疗的效果进行比较。结果:观察组治疗的总有效率为95.3%,明显高于对照组的60.5%,差异有统计学意义(P <0.05),观察组患者的水泡结痂时间、疼痛缓解时间和皮损愈合时间明显短于对照组,差异有统计学意义(P <0.05)。结论:氦氖激光联合更昔洛韦治疗带状疱疹可明显缩短患者的炎性反应和渗出时间,加快组织愈合,临床效果显著。%Objective To observe the curative effect of He - ne laser combined with ganciclovir on shingles. Method 86 shingles pa-tients were selected and divided into two groups. In control group,43 patients were treated by ganciclovir 0. 25 g. In observation group,43 patients were treated by ganciclovir 0. 25 g combined with he - ne laser. Both groups of patients were treated for 7 days. The effects of two groups were compared. Results The total effective rate of observation group was 95. 3% and the total effective rate of control group was 60. 5%. The differences were statistically significant(P < 0. 05). The vesicular scab time,pain relief time,skin lesion healing time of ob-servation group were all less than control group,the differences were statistically significant(P < 0. 05). Conclusion He - ne laser com-bined with ganciclovir on shingles can significantly reduce vesicular scab time and skin lesion healing time and promote tissue healing. The clinical effect is remarkable.

  7. Stimulative Effects of Low Intensity He-Ne Laser Irradiation on the Proliferative Potential and Cell-Cycle Progression of Myoblasts in Culture

    Directory of Open Access Journals (Sweden)

    Cui-Ping Zhang

    2014-01-01

    Full Text Available Low intensity laser irradiation (LILI was found to promote the regeneration of skeletal muscle in vivo but the cellular mechanisms are not fully understood. Myoblasts, normally quiescent and inactivated in adult skeletal muscle, are a type of myogenic progenitor cells and considered as the major candidates responsible for muscle regeneration. The aim of the present study was to study the effect of LILI on the growth potential and cell-cycle progression of the cultured myoblasts. Primary myoblasts isolated from rat hind legs were cultured in nutrient-deficient medium for 36 hours and then irradiated by helium-neon laser at a certain energy density. Immunohistochemical and flow cytometric analysis revealed that laser irradiation could increase the expression of cellular proliferation marker and the amount of cell subpopulations in the proliferative phase as compared with the nonirradiated control group. Meanwhile, the expressions of cell-cycle regulatory proteins in the laser-treated myoblasts were markedly upregulated as compared to the unirradiated cells, indicating that LILI could promote the reentry of quiescent myoblasts into the cell division cycle. These results suggest that LILI at certain fluences could promote their proliferation, thus contributing to the skeletal muscle regeneration following trauma and myopathic diseases.

  8. Experimental study on frequency stabilization method of internal-mirror He-Ne laser%一种内腔式He-Ne激光器频率稳定方法的实验研究

    Institute of Scientific and Technical Information of China (English)

    钱进; 刘忠有; 石春英; 刘秀英; 王建波; 殷聪; 蔡山

    2013-01-01

    Frequency of an internal-mirror He-Ne laser is stabilized by using a micro cooling fan, instead of traditional heating method. Both the relationship between driving voltage and rotating speed and the thermal expansion of the intermal-mirror laser are discussed. The cavity length of the laser is controlled and adjusted by air cooling. The frequency stabilization is based on a theory of power balance between two longitudinal modes. The average temperature of the laser tube is less than 50℃ when the frequency is stabilized. A frequency fluctuation of less than 1.4 MHz in 20 h and a frequency relative standard uncertainty of U= 4.7 × 10-9 in 4 months are evaluated by measuring the beat signal with a high-precision laser stabilized by iodine.%实现了用微型风扇冷却的方法替代常见的加热方式完成对He-Ne内腔激光器的频率稳定.研究了微型风扇驱动电压与转速的响应特性和内腔式He-Ne激光器的热膨胀特性.采用风冷方式对激光器的腔长进行调节和控制,并通过双纵模功率平衡原理完成了激光频率的稳定.稳定后的激光器管壁平均温度低于50℃.与高精度碘稳定激光的拍频实验结果表明,其频率在20h内的波动范围小于1.4 MHz (τ=1 s),4个月内激光频率的相对标准不确定度为U=4.7×10-9.

  9. Ramage Repair for Enhanced Ultraviolet-B Radiation on Antioxidant System of Arabiodopsis by He-Ne Laser%He-Ne激光对增强UV-B辐射拟南芥抗氧化系统的损伤修复

    Institute of Scientific and Technical Information of China (English)

    姜晓燕; 高丽美; 李永峰; 韩榕

    2011-01-01

    以培养6周左右的拟南芥为材料,采用UV-B辐射(剂量1 KJ/m2/d)和He-Ne激光器(波长632.8 nm,输出功率5 mW·mm2,辐照时间60 s)对材料进行处理,分成CK(没有经过UV-B或激光辐照)组、B(UV-B辐射)组、BL(UV-B和激光复合处理)组和L(激光辐照)组4个不同处理组.结果表明:增强的UV-B辐射拟南芥幼苗导致MDA(Malondialdehyde)、超氧阴离子含量升高,GSH(Glutathione)含量降低,PAL(phenylalanine ammomia-lyase)、CAT(catalase)和APX(ascorbate peroxidase)活性升高,SOD(supemxide dismutas)活性降低.单独He-Ne激光处理使MDA、超氧阴离子含量降低,GSH的含量升高,SOD、APX、CAT的活性升高,PAL的活性降低.UV-B辐射后再用He-Ne激光进行后处理,发现与单独UV-B辐照处理相比,MDA、超氧阴离子含量降低,GSH含量升高,SOD、APX、CAT的活性升高了,PAL的活性降低了.因此激光在一定程度上提高了拟南芥叶片抗氧化能力,在此基础上讨论了其可能的形成机理.%Taking Arabidopsis trqined about six weeks as the material, UV-B radiation(1 kJ/m2/d) and HeNe laser irradiation(wavelen 632.8 nm output power 5 mW · mm2 , irradiation time 60 s) were used to process the material. The Arabidopsis were divided into four treatment groups including CK(not treated ),L(He-Ne laser) ,B(UV-B), and BL(UV-B +He-Ne laser). The experimental results show that enhanced UV-B increases the contents of MDA, O2-and the activities of PAL, CAT, APX , while SOD activity and the content of GSH decrease. But He-Ne laser irradiation reduces the contents of MDA and O2- ,the PAL activity, and increases SOD activity, APX activity, CAT activity, the content of GSH . In contrast to B group, both enhanced UV-B and He-Ne laser have similar results which indicated by He-Ne laser irradiation. The results prove that laser can improve the ability of antioxidant system in Arabidopsis.

  10. Investigation of two-frequency Nd{sup 3+} : YAG laser

    Energy Technology Data Exchange (ETDEWEB)

    Arapov, Yu D; Ivanov, A F; Kas' yanov, I V; Magda, L E [E.I. Zababakhin All-Russian Scientific-Research Institute of Technical Physics, Russian Federal Nuclear Centre, Snezhinsk, Chelyabinsk region (Russian Federation)

    2013-02-28

    A repetitively pulsed two-frequency laser is developed. Pulsed operation of a laser based on a Nd{sup 3+} : YAG crystal with simultaneous amplification of radiation at two wavelengths in a single-pass amplifier is studied. (laser optics 2012)

  11. Scattering and absorbing characteristics of human artery and vein in Kubelka-Munk model to 632.8nm wavelength of He-Ne laser in vitro%Kubelka-Munk模型下的人血管对632.8nm氦-氖激光的散射与吸收特性

    Institute of Scientific and Technical Information of China (English)

    魏华江; 李晓原; 刘小星; 魏冬季; 谭润初; 巫国勇

    2001-01-01

    The diffuse reflectance and transmittance of human arteries and veins were studied.632.8nm wavelength of He-Ne laser was used in the experiment.The measurements were performed with two standard integrating sphere system.The absorption coefficient,scattering coefficient and the changes of total optical intensities I(x),forward scattering flux i(x),backward scattering flux j(x) as a function of thickness of human arteries and veins were evaluated and analyzed from the experimented data by Kubelka-Munk model.The results of measurement showed that significant difference of diffuse reflectance and transmittance between arteries and veins at 632.8nm wavelength of He-Ne laser.Furthermore,the absorption coefficient of arteries were obviously lesser than that of veins at He-Ne laser wavelength.And the scattering coefficient of arteries were obviously bigger than that of veins at He-Ne laser wavelength.The changes of total optical intensities I(x),forward scattering flux i(x),backward scattering flux j(x) as a function of human arteries and veins were also significant difference.%本文测量了人动脉和静脉对He-Ne激光的反射和透射传输特性。实验采用两积分球系统及波长为632.8nm的He-Ne激光器,并根据测量数据及采用Kubelka-Munk模型分析和计算了人动脉和静脉组织对该波长激光的吸收系数、散射系数及总的光强I(x)及前向散射通量i(x)和后向散射通量j(x)的变化情况。结果表明,人动脉和静脉内外侧的漫反射率和透射率有明显差别,而且,动脉对激光的吸收系数明显较静脉的要小,而动脉对激光的散射系数却明显较静脉的要大,在动脉和静脉组织中总的光强I(x)及前向散射通量i(x)和后向散射通量j(x)的变化情况也有明显的区别。

  12. Two-frequency picosecond laser based on composite vanadate crystals with {sigma}-polarised radiation

    Energy Technology Data Exchange (ETDEWEB)

    Sirotkin, A A; Sadovskiy, S P; Garnov, Sergei V [A M Prokhorov General Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation)

    2013-07-31

    A two-frequency picosecond laser based on {alpha}-cut Nd:YVO{sub 4}-YVO{sub 4} composite vanadate crystals is experimentally studied for the s-polarised radiation at the {sup 4}F{sub 3/2} - {sup 4}I{sub 11/2} transition with frequency tuning using Fabry-Perot etalons of different thickness. The difference between the radiation wavelengths was tuned within the range of 1.2-4.4 nm. In the mode-locking regime, the two-frequency radiation power was 280 mW at an absorbed pump power of 12 W. (lasers)

  13. 兔血管对He-Ne激光的反射、透射、吸收系数和散射相函数的研究%Reflection,Transmission,Absorption Coefficients and Scattering Phase Function of Rabbit Arteries and Veins at He-Ne Laser in Vitro

    Institute of Scientific and Technical Information of China (English)

    魏华江; 李晓原; 刘小星; 魏冬季; 谭润初

    2001-01-01

    In the present paper,the characterist ic of laser light transporting in rabbit arteries and veins with the aid of the primary theories of photobiology,elementary medical science and physics were stu died.Diffuse reflectance(R) and transmittance(T) of rabbit arteries and veins samples were me asured by a standard integrating spheres system,using He-Ne laser in 632.8?nm wavelength and the absorbance(A) was deduced.The scattering phase function S( θ) were obtained by the experimental arrangement repacked from a spectroscope at angles from -90° to 90°for rabbit arteries and veins samples in 632.8?nm wavelength and the mean cosines of scatter(μ) was calculated.The resul ts showed that the diffuse reflectance of rabbit arteries was bigger than that o f veins at He-Ne laser(P<0.01).The transmittance of rabbit arteries was obviou sly lesser than that of rabbit veins(P<0.01).The absorption coefficient of rabb it arteries was obviously lesser than that of veins.The optical penetration dept h of rabbit veins was obviously lsser than that of rabbit arteries at He-Ne la ser.Rabbit arteries and veins had stronger backward scattering(μα< 0.5, μν0.5),and that backward scattering of rabbit veins was obviously s tronger than that of rabbit arteries at He-Ne laser.There are obvious differenc e of the scattering phase functions between rabbit arteries and veins at He-Ne laser.There are obvious difference of the optical properties between rabbit arte ries and veins to the reflection,transmission,absoprtion coefficients and scatte ring phase functions of He-Ne laser.It is prompted that should be considered wh en He-Ne laser was applied to treat illness of human artery and vein.%本文运用光生物学、基础医学以及物理学的基本理论,探讨了兔血管组织的激光传播特性,定量测定了兔血管组织的激光传输参量.采用标准积分球测量了兔血管组织样品在632.8?nm He-Ne激光照射下的透射率(T)和反射率(R),推算吸收率 (A

  14. Research of the DC discharge of He-Ne gas mixture in hollow core fiber

    Science.gov (United States)

    Wang, Xinbing; Duan, Lian

    2013-09-01

    Since the first waveguide 0.633 μm He-Ne laser from a 20 cm length of 430 μm glass capillary was reported in 1971, no smaller waveguide gas laser has ever been constructed. Recently as the development of low loss hollow core PBG fiber, it is possible to constract a He-Ne lasers based on hollow-core PBG fibers. For the small diameter of the air hole, it is necessary to do some research to obtain glow discharge in hollow core fibers. In this paper, the experimental research of DC discharge in 200 μm bore diameter hollow core fibers was reported. Stable glow discharge was obained at varioue He-Ne mixtures from 4 Torr to 18 Torr. In order to obtain the plasma parameter of the discharge, the trace gasses of N2 and H2 were added to the He-Ne mixtures, the optical emission spectroscopy of the discharge was recorded by a PI 2750 spectroscopy with a CCD camera. The gas temperature (Tg) could be obtained by matching the simulated rovibronic band of the N2 emission with the observed spectrum in the ultraviolet region. The spectral method was also used to obtained the electron density, which is based on the analysis of the wavelength profile of the 486.13 nm Hβ line, and the electron temperature was obtain by Boltzmann plot methods. Experimental results show that it is very difficult to achieve DC discharge in bore diameter less than 50 μm, and a RF discharge method was proposed. Project supported by the National Natural Science Foundation of China (61078033).

  15. He-, Ne-, and Ar-phosgene intermolecular potential energy surfaces

    DEFF Research Database (Denmark)

    Munteanu, Cristian R.; Henriksen, Christian; Felker, Peter M.

    2013-01-01

    Using the CCSD(T) model, we evaluated the intermolecular potential energy surfaces of the He-, Ne-, and Ar-phosgene complexes. We considered a representative number of intermolecular geometries for which we calculated the corresponding interaction energies with the augmented (He complex) and double...

  16. Effect of low intensity He - Ne laser intravascular irradiation therapy on blood rbeology in patients with type 2 diabetes mellitus%低强度He-Ne激光血管内照射对Ⅱ型糖尿病患者血液流变学的影响

    Institute of Scientific and Technical Information of China (English)

    侍晓云; 刘亚力

    2001-01-01

    目的:探讨低能量He-Ne激光血管内照射(ILIB)对Ⅱ型糖尿病患者血液流变学的影响,为ILIB临床应用提供依据。方法:观察258例Ⅱ型糖尿病患者ILIB治疗前后血液流变学变化。结果:经ILIB治疗后患者血沉、红细胞压积,全血比粘度、全血还原比粘度,血浆比粘度,红细胞聚集指数、红细胞变形指数、纤维蛋白原较治疗前均降低(P<0.05)。结论:ILIB能有效地改善Ⅱ型糖尿病患者的血液流变学状态,这对改善微循环,防治并发症有重要的临床意义。%Objective: To study the effect of low intensity He - Ne laser intravascular irradiation therapy on blood rheology of patients with type 2 diabetes mellitus and its mechanism. Methods: The blood rheological indexes were measured, and the data before and after treatment were compared. Results: The ESR hematocrit, whole blood viscosity, blood reduction viscosity, plasma viscosity and erythrocyte aggregation index were decreased significantly after tereatment as compared with those before treatment. (P<0.05). Conclusion: He- Ne laser intravascular irradiation therapy may improve the blood rheology effectively and beneficial to improvement of microcirculation.

  17. Matlab编程法在测量氦氖激光波长实验数据处理中的应用探索%Exploration of Matlab Programming Method is Applied in the Data Processing of Measurement of He Ne Laser Wavelength in the Experiment

    Institute of Scientific and Technical Information of China (English)

    夏雪琴

    2015-01-01

    使用新型的WSM-T-Ⅱ型台式迈克尔逊干涉仪可以测量氦氖激光波长,传统的数据处理方法是逐差法,计算量大,既繁琐又容易出错。用Matlab软件的编程法处理实验测得的数据,程序运行后可以直接得到氦氖激光波长及相应的误差分析,无需进行运算,准确而快捷,是大学物理实验教学中实验数据处理的一种新方法。%The use of WSM-T-type II desktop Michelson novel interferometer can measure the helium neon la-ser wavelength,the method of data processing is the traditional difference method,a large amount of calcula-tion,tedious and error prone. The measured data by programming method in the treatment of experimental Mat-lab software,running the program can be directly obtained from the analysis of He Ne laser wavelength and the corresponding error,no need of operation,accurate and fast,and it is a new method of experimental data pro-cessing of physical experiment teaching in university.

  18. clinical Observation of He-Ne Laser Combined with Drug in the Treatment of Pulmonary Infection%氦氖激光配合药物治疗肺部感染疗效观察

    Institute of Scientific and Technical Information of China (English)

    黄丽君

    2015-01-01

    Objective To improve the treatment of pulmonary infections.Methods 40 cases of pulmonary infections in patients with a helium-neon laser ir adiation,ir adiation time each 15min,2 times a day for one week irradiation.Over the same period 40 cases of pulmonary infection control group,drug treatment,the two groups of clinical symptoms and lesions time to compare the absorption rate, explore helium-neon laser treatment of pulmonary infection.Results The treatment group clinical improvement shorter than the control group after one week of treatment foci ef ective rate was higher ( <0.05).Conclusion Helium-neon laser treatment of pulmonary infection had a significant ef ect,economical and practical,simple,and secure,no adverse reactions.%目的为了提高治疗肺部感染的疗效。方法对40例肺部感染患者进行氦氖激光照射,每次各照射15min,2次/d,连续照射1w。同期选取40例肺部感染对照组,单纯药物治疗,将两组临床症状改善时间及病灶吸收率进行比较,探讨氦氖激光治疗肺部感染的效果。结果治疗组临床症状改善时间短于对照组,治疗1w后病灶吸收有效率均高于对照组(<0.05)。结论应用氦氖激光治疗肺部感染有显著效果,经济实用、操作简单、且安全可靠,无不良反应。

  19. THE EFFECTS OF HE- NE LASER COMBINING WITH UNION ASTRAGALUS INJECTION ON BONE MARROW HEMATOPOIETIC%氦氖激光联合黄芪注射液对小鼠骨髓造血细胞的影响

    Institute of Scientific and Technical Information of China (English)

    李仙峰; 崔明玉; 崔珈衔; 任明姬

    2011-01-01

    Objective: To investigate low intensity helium -neon laser combining with the union astragalus on mouse marrow hemopoiesis, to provide the new method for clinical increase the hematopoietic stem cell. Method: Astragalus injection after dosage 4.20 J/cm2 helium neon laser stimulation mouse, examines each group with the class type cell technique the hematopoietic stem cell Sca - 1 masculine gender rate expression situation and the marrow hematopoietic cell cycle change. Result: Various experimental groups mouse marrow hematopoietic stem cell Sca - 1 masculine gender rate expression and the marrow hematopoietic cell cycle of the S time, the G2/M time's cell proportion obviously advances, 4.20 J/cm2 laser show and the astragalus injection union group result is most remarkable. Conclusion:The low intensity helium neon laser have the stimulation multiplication function to the mouse marrow hematopoietic cell, and the astragalus injection has the coordination stimulation with it.%目的:研究低强度氦氖激光及联合黄芪注射液对小鼠骨髓造血细胞的影响,为临床扩增造血干细胞提供新的方法和实验依据.方法:黄芪注射液与4.20 J/cm2氦氖激光刺激小鼠后,用流式细胞术检测各组的造血干细胞Sca-1阳性率的表达情况及骨髓造血细胞的周期变化.结果:各实验组小鼠骨髓造血干细胞Sca-1阳性率的表达及骨髓造血细胞周期中S期、G2/M期的细胞比例均明显增高,且激光照射与黄芪注射液联合组结果最显著.结论:低强度氦氖激光能够对小鼠骨髓造血细胞产生刺激增殖作用,且黄芪注射液与其有协同刺激作用.

  20. He-Ne激光对正畸牙根吸收影响的组织形态学研究%Effect of He-Ne laser irradiation on root resorption induced by orthodontical treatment

    Institute of Scientific and Technical Information of China (English)

    徐焱; 孙新华

    2012-01-01

    Objective To invesligale the effecl of low power laser irradialion on rool resorplion induced by heavy force during the experimental Loolh movemenl. Methods Fifty - five Wislar rals were used in this study. The animals were divided into 11 groups of 5 animals each; 5 groups of animals as irradiated groups were exposed to low power laser irradiation for 15 minutes per day after orthodontic treatment, 5 groups of animals as control groups did not receive low power laser irradiation, and 1 group of animals as blank control group was left untreated. An orthodontic appliance, consisting of a coil spring, connected the left first molar and the two incisors by ligature wire. 90 g force was used in the experiment as heavy force. The animals were sacrificed on days 1,4,7, 14, and 21. Tartrate resistant acid phosphatase (TRAP) staining and HE staining were used for observing root resorption and counting osteoclast cells. I - testwas used for statistical analysis. Results The earliest root resorption was detected on day 4 in the circumference of necrotic hyalinized tissue. On day 7, the osteoclast -like cells close to cementum in control group outnumbered those in irradiated group (P<0. 05) , reaching the peak on day 14(P<0. 01). On day 14, serious root loss deep into dentine could be often observed in the pressure side. After 21days, resorption stopped generally. The area of resorption in irradiated group was significantly smaller than in control group (P < 0. 01) . Besides, the repair process of root resorption was detected on day 21 in the irradiated group. The cells involved in root resorption were mono - and multi - nucleated TRAP - positive cells. Conclusions Low power laser irradiation not only accelerates alveolar bone and periodontal tissue turn - over during tooth movement but also reduces root resorption effectively.%目的 通过组织形态学观察He-Ne激光照射对实验性牙移动根吸收的影响与作用.方法 选用Wistar大鼠建立根吸收的动物

  1. 用迈克尔逊干涉仪测量He-Ne激光波长的测量不确定度分析%Measurement Uncertainty Evaluation to the Experiment of Wavelength Measurement of He-Ne Laser with a Michelson Interferometer

    Institute of Scientific and Technical Information of China (English)

    王潮; 李霄洋; 王丽香

    2014-01-01

    In this paper the error source of the measurement of the wavelength of He-Ne laser with a Michelson interferometer is analyzed,especially aim to the problem that the measurement result is usually larger than the true value of the wavelength. We found that the main error comes from the defect in the light system and the backlash error remained in the Michelson interferometer. An improving method is put forward and the measure-ment uncertainty is reasonably evaluated.%针对迈克尔逊干涉实验中测出的He-Ne激光的波长值总是比真实值偏大的问题,分析了用迈克尔逊干涉仪测量He-Ne激光波长时的实验误差来源,发现实验光路调整的不理想以及仪器读数装置中残留的螺纹空程差是导致λ值偏大的主要原因。在此基础上提出了相应的改进办法,并且对测量不确定度进行了合理的估算。

  2. Two-wavelength HeNe laser interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Granneman, E.H.A.

    1981-03-24

    This paper presents an interferometer set-up in which two wavelengths are used simultaneously. This enables one to determine separately the phase shifts caused by changes in plasma density and by mechanical vibrations of the interferometer structure.

  3. 氮氖激光与电针穴位刺激对新生大鼠脑缺血缺氧后海马神经元存活的影响%Impacts of He-Ne laser and electric acupuncture on hippocampal neuron survival in cerebral hypoxic ischemia in neonatal rats

    Institute of Scientific and Technical Information of China (English)

    吴爱群; 高艳; 刘伟; 李宛青; 曾光伟; 万国兰

    2004-01-01

    BACKGROUND: Hypoxic-ischemic brain damage (HIBD) that often results in cerebral palsy continues to be a common disease in perinatal medicine. At present, no effective therapeutic strategies has yet been developed to counteract this condition.OBJECTIVE: To study the effect of He-Ne laser acupoint irradiation and electric acupuncture on hippocampal neuron survival and development as well as the expressions of brain-derived neurotrophic factor(BDNF) and choline acetyl transferase(ChAT) in HIBD in neonatal rats. To compare and analysis the different effectiveness of two treatments in order to explore the new method against HIBD.DESIGN: A completely randomized controlled study.SETTING and PARTICIPANTS: The study was conducted at the Department of Anatomy of the Second Military Medical University of Chinese PLA and Zhengzhou University. Fifty-eight seven-day-old rats were obtained from the experimental animal center of Henan Province with a body mass ftom 12to 15 g in either gender.INTERVENTIONS: Rats were randomly allocated into four groups: control group(Ⅰ) that neither ligated nor exposed to hypoxia, HIBD group(Ⅱ) that exposed to hypoxic-ischemic condition, laser irradiation group( Ⅲ ) and electric acupuncture group(EA, Ⅳ ) . Left brain Hypoxic-ischemic injury model were established in all animals of Ⅱ - Ⅳ groups on basis of Yu Xiaohong' s animal model of unilateral hypoxia-ischemia in neonatal rats. Animals in group Ⅲ and V were treated either with He-Ne laser acupoint irradiation( Ⅲ ) or EA( Ⅳ ) in the next day following hypoxia synchronously by choosing dazhui and baihui acupoints for the treatment. Fifty-eight rats were subjected to perfusion-fixation 22 days later, the left brains were paraffin wax embdded, sectioned and stained by HE and Nissl staining as well as ChAT and BDNF immunohistochemical staining.MAIN OUTCOME MEASURES: The neurons and Nissl bodies were observed, the grey scale values were measured and the number of ChAT and BDNF

  4. Plasma Density Measurements in Cable Gun Experiments with a Sensitive He-Ne Interferometer

    Institute of Scientific and Technical Information of China (English)

    CHEN Lin; HE An; JIANG Wei; XU Min; WU Shoudong; LI Ye

    2007-01-01

    A time-resolved sensitive He-Ne laser interferometer without complicated active stabilization was built up and applied to low-density plasma measurements. A precision of about 0.2° in phase measurements was achieved with a minimum line-integrated plasma density as low as 8.3×l013 cm-2. With this interferometer, the characteristics of the plasma generated by a cable plasma gun was investigated systematically. The reproducibility, spatial and temporal distributions and the averaged injection velocity of the plasma are presented. In addition, the interaction of the plasma flow with a conductor was studied by placing a metal plate in the downstream of the cable gun.

  5. 低强度氦氖激光血管内照射治疗对海洛因戒断症状抑制效应的定量评估%Quantitative efficacy evaluation of intravascular low-level He-Ne laser irradiation for heroin withdrawal syndrome

    Institute of Scientific and Technical Information of China (English)

    贾文英; 田红召; 杨婷婷; 海国军

    2005-01-01

    BACKGROUND: Intravascular low-level laser irradiation (ILLLI) therapy with He-Ne laser can effectively inhibit the occurrence of heroin withdrawal syndrome, but the therapeutic effect should be evaluated by quantitative standards.OBJECTIVE: To evaluate the effect of intravascular low-level He-Ne laser irradiation against withdrawal syndrome with intravenous according to the criteria proposed by the authors.DESIGN: Randomized controlled trial in heroin-addicted patients.SETTING: Analysis and Testing Laboratory of Xinxiang Medical College and Center of Laser Medical Research of Zhenzhou University Medical CollegePARTICIPANTS: The study was completed in Center of Laser Medical Research in Zhengzhou University in January 2003. Thirty heroin addicts from the Detoxification Center of Zhengzhou including 25 male and 5 female patients aged 19- 45 years were divided randomly into experimental group and control group with 15 cases in each. The patients' history of drug abuse ranged from 0. 5 to 5 years and the daily doses they took was 1.0-4.0 g.INTERVENTIONS: Patients in the experimental group were treated by ILLLI therapy after hospitalization. The therapy was administered once daily for 60 minutes in each session, for a total of 10 days for a treatment course. The irradiating power of the laser was 2.0-3.0 mW with a power density of 7.07-10.6 mW/mm2. Patients in the control group were treated with conventional therapy with algidon combined with buprenorphine hydrochloride. The 12 main symptoms(vomiting, goose pimples, sweating, agitation, shaking, lacrimation, nasal congestion, insomnia, abdominal pain,body temperature changes, muscular pain, and heart rate changes) were scored for 0, 1, 2, and 3 corresponding to absent, mild, moderate, and severe symptoms, with the total score of 36.MAIN OUTCOME MEASURES: Comparison of the scores for the withdrawal symptoms between the two groups.RESULTS: The 30 cases were all available for result analysis. The scores of vomiting

  6. Biological effect of intravascular low intensity He-Ne laser irradiation on ischemic cerebrovascular disease%弱氦氖激光血管内照射治疗缺血性脑血管疾病的生物学效应

    Institute of Scientific and Technical Information of China (English)

    孔双艳; 何俐; 杨蓉

    2005-01-01

    目的:弱氦氖激光血管内照射是激光、光纤、光电技术与临床化学相结合的一项技术,应用于缺血性脑血管疾病的治疗是否具有其特殊的生物学效应?资料来源:检索数据库Cochrance Central Register of Controlled Trial(4th Quarter 2004) 、 Database of Abstracts of Reviews of effectiveness (4th Quarter 2004)、 ACP Journal Club (1991/ 2004)、 Cochrance Databases of Systematic Review (4th Quarter 2004)、 Medline(1980-12/2004)、CBM -中国生物医学文献数据库(1982/2004)、中文全文期刊数据库(1989/2004)与弱氦氖激光血管内照射和缺血性脑血管疾病相关的文献,检索词:Intravascular Low Intensity He-Ne Laser Irradiation on Blood;Ischemic Cerebrovascular Disease或"弱氦氖激光血管内照射,脑缺血",限定语言种类为英文或中文.资料选择:文章纳入标准:①随机或半随机对照试验及相关的系统评价.②研究对象为任何年龄、性别不限的缺血性脑血管疾病的患者或动物模型.③相关的基础研究.排除标准:①设计方法不严格的重复研究.②个案报道.③经验总结.资料提炼:共收集到38个随机或半随机对照试验,纳入11个临床试验、4个基础试验和1个文献评价.资料综合:11个临床试验包括846例患者,分别对应用弱氦氖激光血管内照射方案进行治疗者其生物学改变予以评价.仅有3篇文章报告了副作用.4个基础试验是弱氦氖激光血管内照射对动物模型和体外的一些研究结果.弱氦氖激光血管内照射通过改善血液流变,增加血流速度,增强氧合作用,清除自由基,减轻白细胞对微循环的影响及调整血脂异常起到治疗脑缺血的作用.结论:弱氦氖激光血管内照射治疗缺血性脑血管疾病的生物学效应明显,不良反应少.但由于纳入的大多数文献报道有缺陷,还需要进行大量的严格的基础和临床试验.

  7. Gain enhancement in a two-frequency high-gain waveguide free-electron laser

    CERN Document Server

    Lefèvre, T; Rullier, J L; Gouard, P; Donohue, J T

    2002-01-01

    In a waveguide monomode free-electron laser (FEL), two resonant frequencies can be amplified by the electron beam. At the CEA/CESTA facility, single-pass high-gain FEL experiments have been performed over the last five years using relativistic electron beams provided by induction linacs. Most of the work was done in the amplifier regime (at the higher frequency) with the aim of producing a 35 GHz bunched beam. However, super-radiant measurements were also made and have shown that the FEL gain at the upper frequency is higher than in the amplifier regime and may be driven by the lower frequency FEL interaction.

  8. He-Ne激光重复照射抑制培养增生性瘢痕成纤维细胞胶原合成的实验研究%Inhibitory effects of He Ne laser repeated irradiation on collagen synthesis in hypertrophic scar derived fibroblasts in culture

    Institute of Scientific and Technical Information of China (English)

    杨宏珍; 杨西川

    2002-01-01

    Objective To explore the inhibitory effects of He Ne laser repeated irradiation on the collagen synthesis of cultured scar fibroblasts. Method Cultured fibroblasts derived from hypertrophic scars(HS) were irradiated with He Ne laser for 30 minutes at various power densities(10,50,100 and 150 mW/cm2),once a day for 3 consecutive days.In 24 hours after repeated irradiation collagen production and type I procollagen mRNA level of fibroblasts were measured with the incorporation of 3H proline and blot hybridization techniques espectively.Results Collagen synthesis and type I procollagen mRNA level remained unchanged when the laser was irradiated at the power density of 10 mW/cm2 or 50 mW/cm2.Compared with control,collagen synthesis and type I procollagne mRNA level were significantly decreases at the power density of 100 mW/cm2 or 150mW/cm2(P< 0.05).Type I procollagen mRNA level at the power densityof 150 mW/cm2 was lower than that at the 100 mW/cm2 (P< 0.05).Conclusion Repeated He Ne laser irradiation at the power density of 100 mW/cm2 or 150 mW/cm2 can suppress collagen synthesis of cultured fibroblasts in HS.The cause of suppression may be associated with down regulation of type I procollagen mRNA expression.

  9. Structure and Stability of Endohedral Complexes X@(HAlNH)12 (X = He, Ne, Ar, Kr)

    Institute of Scientific and Technical Information of China (English)

    ZHANG Cai-Yun; WU Hai-Shun

    2005-01-01

    The structures of closo-hedral cluster (HAlNH)12 and endohedral complexes X@(HAlNH)12 (X = He, Ne, Ar, Kr) have been studied by using density functional theory (DFT) at the B3LYP/6-31G(d) level. The geometries, natural bond orbital (NBO), vibrational frequency, energetic parameters, magnetic shielding constants and nucleus independent chemical shifts (NICS) were discussed. The potential surface of guest X shifting from the cage center to a face of six- membered ring was calculated at the same level. The exit transition state was demonstrated with IRC calculations. It is found that X@(HAlNH)12 complexes are dynamically stable, and Ne@(HAlNH)12 is more energetically favorable than the other complexes in thermodynamics.

  10. Further studies of double ionization of He, Ne, and Ar by fast and slow antiprotons

    Science.gov (United States)

    Andersen, L. H.; Hvelplund, P.; Knudsen, H.; Møller, S. P.; Pedersen, J. O. P.; Tang-Petersen, S.; Uggerhøj, E.; Elsener, K.; Morenzoni, E.

    1989-12-01

    Measurements of the ratio R between double- and single-ionization cross sections for antiproton impact on He, Ne, and Ar targets are reported for impact energies ranging from 65 keV to 20 MeV. At high energies the results are found to merge with proton results at around 20 MeV, and the high-energy limit of the common ratio is in good agreement with recent first-Born-calculation results for the helium target. The large difference previously observed in the ratio R for protons and antiprotons at energies between 0.5 and 5 MeV is found to persist down to the lowest energies investigated here.

  11. Further studies of double ionization of He, Ne, and Ar by fast and slow antiprotons

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, L.H.; Hvelplund, P.; Knudsen, H.; Moller, S.P.; Pedersen, J.O.P.; Tang-Petersen, S.; Uggerhoj, E. (Institute of Physics, University of Aarhus, DK-8000 Aarhus C, Denmark (Denmark)); Elsener, K. (CERN, CH-1211 Geneva 23, (Switzerland)); Morenzoni, E. (PSI, CH-5234 Villigen, (Switzerland))

    1989-12-15

    Measurements of the ratio {ital R} between double- and single-ionization cross sections for antiproton impact on He, Ne, and Ar targets are reported for impact energies ranging from 65 keV to 20 MeV. At high energies the results are found to merge with proton results at around 20 MeV, and the high-energy limit of the common ratio is in good agreement with recent first-Born-calculation results for the helium target. The large difference previously observed in the ratio {ital R} for protons and antiprotons at energies between 0.5 and 5 MeV is found to persist down to the lowest energies investigated here.

  12. Infrared multiphoton dissociation of octafluorocyclobutane with a two-frequency Q-switched CO/sub 2/ laser

    Energy Technology Data Exchange (ETDEWEB)

    Pochon, E.; Weston, R.E. Jr.; Flynn, G.W.

    1985-01-03

    The infrared multiphoton dissociation of octafluorocyclobutane has been investigated by the use of two CO/sub 2/ laser pulses of different frequency, synchronized by the same Q-switching mirror. The dissociation yield has been determined as a function of laser pulse energy, frequency of the dissociating pulse, substrate pressure, and interpulse delay. Accompanying transport phenomena (expansion and diffusion) were taken into account by the use of appropriate models. The kinetic behavior of highly vibrationally excited c-C/sub 4/F/sub 8/ molecules indicates that collisional relaxation occurs at nearly gas kinetic rates. 47 references, 10 figures.

  13. 肾移植重症肺部感染患者氦氖激光胸部理疗的治疗效果分析%Curative effect of He-Ne laser chest physiotherapy on renal transplant patients with severe pulmonary infections

    Institute of Scientific and Technical Information of China (English)

    冯霞; 姚伟; 何春婷; 杜立萍; 王莉

    2016-01-01

    目的:观察氦氖激光胸部理疗对肾移植后重症肺炎患者的治疗效果,为肾移植后重症肺炎的治疗提供参考。方法将42例肾脏移植后发生重症肺部感染的患者采用随机数字表法分为观察组和对照组,每组各21例;对照组患者早期选择广谱抗菌药物联合抗真菌药物治疗,对于明确病毒感染的患者抗病毒药物治疗,待病原学检测结果选择敏感的抗菌药物治疗;观察组在对照组综合治疗的基础上,辅以氦氖激光治疗仪治疗。两组患者在治疗前均进行痰液培养及药敏试验、血巨细胞病毒DNA检测及尿巨细胞病毒快速培养。比较两组患者治疗10天后的体温、白细胞计数氧合指数及临床肺部感染评分(CPIS);评价两组患者的治疗效果。结果观察组19例患者检测出25株病原体,对照组20例患者检测出24株病原体,两组患者均以革兰氏阴性菌及巨细胞病毒感染为主;药敏试验结果显示:革兰阴性菌对头孢哌酮/舒巴坦耐药性最低,革兰阳性菌对万古霉素最敏感,真菌对氟康唑最敏感;治疗10天后,观察组患者在体温、白细胞计数、氧合指数及 CPIS 评分的改善程度优于对照组( P<0.05);观察组的总有效率为90.5%,显著高于对照组61.9%( P<0.05)。结论氦氖激光辅助治疗可改善肾移植后重症肺炎患者的病情,提高其临床治疗效果。%OBJECTIVE To observe the curative effect of He‐Ne laser chest physiotherapy on renal transplant pa‐tients with severe pneumonia so as to provide guidance for treatment of severe pneumonia .METHODS A total of 42 renal transplant patients complicated with severe pulmonary infections were enrolled in the study and randomly di‐vided into the observation group and the control group ,with 21 cases in each .The control group was treated with early broad‐spectrum drug therapy combined with antifungal drug

  14. Investigation on the crystal growth, molecular structure and nonlinear optical susceptibilities of 2-[2-(4-Ethoxy-phenyl)-vinyl]-1-ethyl-stilbazolium iodide (EESI) by Z-scan technique using He-Ne laser for third-order nonlinear optical applications

    Science.gov (United States)

    Senthil, K.; Kalainathan, S.; Kondo, Y.; Hamada, F.; Yamada, M.

    2017-05-01

    Organic 2-[2-(4-Ethoxy-phenyl)-vinyl]-1-ethyl-stilbazolium iodide (EESI), a derivative of the stilbazolium family single crystal was synthesized by condensation method. Nearly perfect as-gown single crystals of EESI structure was confirmed by single-crystal X-ray diffraction studies. The crystal has a triclinic system with the space group P-1, the molecule consists of one pyridinium cation, one iodide anion, and 0·5H2O molecules. The nature of charge transfer, molecular properties, electrostatic potential map, and HOMO-LUMO energy gap of EESI have been theoretically investigated by Sparton'10 V1.0.1 program. The optical transparency of EESI was studied by Uv-Visible spectral analysis. The growth features were observed during the etching studies using a Carl Zeiss optical microscope (50X magnification). The mechanical behavior of the crystal was estimated by Vickers microhardness test, which shows reverse indentation size effect (RISE) with good mechanical stability. Both the dielectric constant and dielectric loss increases with the increasing temperature and attain almost constant at higher frequencies, which justify the crystal quality and essential parameter for electro-optic device applications. The complex impedance analysis explains the electrical property of EESI. TGA and DTA measurements determined the thermal stability of the grown crystal. Laser-induced damage threshold energy measurements exhibit that the excellent resistance with good threshold energy up to 2.08 GW/cm2 that was found to be more than that of some known organic and inorganic NLO crystals. Photoconductivity of EESI crystal confirms that the positive photoconductivity nature. Also, the third-order nonlinear optical (NLO) properties of EESI were investigated by using the single beam Z-scan technique under the Visible light (632.8 nm) region. The results show that EESI has effective third-order nonlinear optical property with the nonlinear refractive index n2 =1.787×10-11m2/W, third

  15. Multiple ionization of He, Ne, and Ar by fast protons and antiprotons

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, L.H.; Hvelplund, P.; Knudsen, H.; Moller, S.P.; Sorensen, A.H.; Elsener, K.; Rensfelt, K.; Uggerhoj, E.

    1987-10-15

    Single and multiple ionization of He, Ne, and Ar has been studied experimentally by impact of fast protons and antiprotons. The single-ionization cross sections obtained with protons and antiprotons are found to be the same. The double-ionization cross sections obtained with antiprotons, however, are much larger than those obtained with protons at equal velocity. This difference is found for all three gases but the effect is largest for He and Ne, where the difference is about a factor of 2 at 1 MeV/amu. The difference is discussed in terms of interference between two collision mechanisms which both result in double-electron escape. Experimental information on the magnitude of the interference term is obtained by inclusion of double-ionization data, partly obtained in this work, for fast electron and ..cap alpha..-particle impact. For triple ionization of Ne, we also find that antiprotons yield much larger cross sections than protons do. Identical cross sections, however, are found for triple ionization of Ar with protons and antiprotons. This is believed to be due to the fact that triple ionization of Ar is mainly a consequence of a single vacancy produced in an inner shell followed by electronic rearrangement. This observation supports the interpretation that the observed charge effect is due to an interference effect in the outermost shell.

  16. Silicon surface modifications produced by non-equilibrium He, Ne and Kr plasma jets

    Science.gov (United States)

    Engelhardt, Max; Kartaschew, Konstantin; Bibinov, Nikita; Havenith, Martina; Awakowicz, Peter

    2017-01-01

    In this publication the interaction of non-equilibrium plasma jets (N-APPJs) with silicon surfaces is studied. The N-APPJs are operated with He, Ne and Kr gas flows under atmospheric pressure conditions. Plasma bullets are produced by the He and Ne N-APPJs, while a filamentary discharge is ignited in the Kr flow. All these N-APPJs produce remarkable traces on silicon wafer surfaces treated in their effluents. Different types of etching tracks, blisters and crystals are observed on the treated surfaces. The observed traces and surface modifications of silicon wafers are analyzed with optical, atomic-force, scanning electron and Raman microscopes. Based on the material composition within the etching tracks and the position and dimension of blisters and crystals, the traces observed on the silicon wafer surfaces are interpreted as traces of micro-plasmoids. Amorphous silicon is found in the etching tracks. Blisters are produced through the formation of cracks inside the silicon crystal by the interaction with micro-plasmoids. The reason for these modifications is not clear now. The density of micro-plasmoids traces on the treated silicon surface and the depth and length of the etching tracks depends strongly on the type of the used carrier gas of the N-APPJ.

  17. Locking phenomenon of polarization flipping in He-Ne laser with a phase anisotropy feedback cavity.

    Science.gov (United States)

    Chen, Wenxue; Zhang, Shulian; Long, Xingwu

    2012-03-01

    In this article, the locking phenomenon of polarization flipping is reported. A model that integrates the model of the equivalent cavity of a Fabry-Perot interferometer and Lamb's semiclassical theory is built to explain the locking phenomenon. On the basis of analysis of the model, a method is proposed to release the locking of polarization flipping. After solving the problem of lock-in, the system in this paper can be used to measure small stress of the optical component and phase retardation of the birefringence component.

  18. Effect of laser irradiation of donor blood on erythrocyte shape.

    Science.gov (United States)

    Baibekov, I M; Ibragimov, A F; Baibekov, A I

    2012-04-01

    Changes in erythrocyte shape in donor blood during storage and after irradiation with He-Ne laser and infrared laser were studied by scanning electron microscopy, thick drop express-method, and morphometry. It was found that laser irradiation delayed the appearance of erythrocytes of pathological shapes (echinocytes, stomatocytes, etc.) in the blood; He-Ne laser produced a more pronounced effect.

  19. 甘草酸苷联合卤米松乳膏和氦氖激光照射治疗斑秃对血清白三烯B4、白三烯C4、C反应蛋白和白介素-10的影响%The effect of serum leukotriene B4,leukotriene C4,C-reactive protein and interleukin-10 after treatment alopecia areata by glycyrrhizin combined with halometasone cream and He-Ne laser

    Institute of Scientific and Technical Information of China (English)

    张玉刚; 杨秀凤

    2015-01-01

    目的:研究甘草酸苷联合卤米松乳膏和氦氖激光照射治疗斑秃及治疗前后患者外周静脉血清白三烯B4、白三烯C4、C反应蛋白和白介素-10的变化,为临床有效治疗斑秃提供科学依据。方法:2013年2月-2014年8月,采用复方甘草酸苷片(日本米诺发源制药株式会社研制生产)联合卤米松乳膏(上海通用药业有限公司生产)局部涂抹和氦氖激光照射治疗斑秃。3个月后评价疗效并采用ELISA法检测患者血清白三烯B4、白三烯C4、C反应蛋白和白介素-10的水平。结果:卤米松乳膏组、卤米松乳膏激光组和联合治疗组有效率分别为70%、82.5%,97.5%。联合治疗组疗效优于卤米松乳膏组和卤米松乳膏激光组,三组间差异均有统计学意义(χ2分别为9.95和4.31,P<0.05)。联合治疗组白三烯B4、白三烯C4、C反应蛋白和白介素-10水平较卤米松乳膏组和卤米松激光组明显降低(P<0.05)。结论:复方甘草酸苷联合卤米松乳膏和局部激光照组射治疗斑秃,可以达到调节患者的自身免疫力,改善斑秃皮损部位血液微循环,增加毛囊的供血、供氧,有效提高斑秃的治愈率,并且无明显严重不良反应,是皮肤科临床治疗斑秃的有效手段之一,非常值得在基层医院皮肤科推广。%Objective Study on glycyrrhizic acid glycosides joint halide halometasone cream and He-Ne laser irradiation treatment of alopecia areata and before and after treatment in patients with peripheral venous serum leukotriene B4,leukotriene C4,C- reactive protein and the changes of interleukin- 10,provide scientific basis for clinical effective in the treatment of alopecia areata. Methods From February 2013 to August 2014,adopting compound glycyrrhizin glucoside piece (Japan mino originated,developed and produced by pharmaceutical Co.,LTD)joint halide halometasone cream (Shanghai general pharmaceutical Co

  20. Solar cycle variation of interstellar neutral He, Ne, O density and pick-up ions along the Earth's orbit

    OpenAIRE

    Sokół, Justyna M.; Bzowski, Maciej; Kubiak, Marzena A.; Möbius, Eberhard

    2016-01-01

    We simulated the modulation of the interstellar neutral (ISN) He, Ne, and O density and pick-up ion (PUI) production rate and count rate along the Earth's orbit over the solar cycle from 2002 to 2013 to verify if solar cycle-related effects may modify the inferred ecliptic longitude of the ISN inflow direction. We adopted the classical PUI model with isotropic distribution function and adiabatic cooling, modified by time- and heliolatitude-dependent ionization rates and non-zero injection spe...

  1. Effects of He-Ne regional irradiation on 53 cases in the field of pediatric surgery

    Science.gov (United States)

    Guo, Jing-Zhen

    1991-06-01

    We report the clinical observation of the effect on 53 surgical cases with Helium-Neon laser local irradiation therapy. Of those cases 15 were suffered from chronic and acute infection, 5 were traumatic, 15 of hemangioma had been treated by solid CO freezing therapy and sclerosing injection previously. 18 cases were received incisional irradiation postoperatively. All showed remarkable results. There were no infection, and the healing process was shortened by Helium-Neon laser local irradiation for 2-3 days. The results showed that the curative rate was 88.68%, the marked effective rate was 9.43%, and the fair was 1.89$. We emphasize that because of the characteristic of anatomical physiology and histology in children. so the result in children is better than in adults. Thus, we strongly recommend using Helium-Laser local irradiation in surgical pediatric field. It is reliable, safe, painless, convenient, economic, and no side effects at all.

  2. Osteoarthrosis and nonarticular rheumatism treated by low laser

    Science.gov (United States)

    Antipa, Ciprian; Moldovan, Corneliu I.; Crangulescu, Nicolae; Podoleanu, Adrian Gh.; Vasiliu, Virgil V.

    1995-03-01

    557 patients with various noninflammatory rheumatism (osteoarthrosis and nonarticular) were treated in four different ways: with GaAs laser, 1 - 2 mW output power alone, with HeNe laser, 2 mW alone, with GaAs and HeNe together and with classical antiflammatory therapy.

  3. Coupled cluster calculations of mean excitation energies of the noble gas atoms He, Ne and Ar and of the H2 molecule

    DEFF Research Database (Denmark)

    Sauer, Stephan P. A.; Haq, Inam U.; Sabin, John R.

    2013-01-01

    Using an asymmetric-Lanczos-chain algorithm for the calculation of the coupled cluster linear response functions at the CCSD and CC2 levels of approximation, we have calculated the mean excitation energies of the noble gases He, Ne and Ar, and of the hydrogen molecule H2. Convergence with respect...

  4. Experimental and theoretical studies of the infrared spectra and bonding properties of NgBeCO₃ and a comparison with NgBeO (Ng = He, Ne, Ar, Kr, Xe).

    Science.gov (United States)

    Zhang, Qingnan; Chen, Mohua; Zhou, Mingfei; Andrada, Diego M; Frenking, Gernot

    2015-03-19

    The novel neon complex NeBeCO3 has been prepared in a low-temperature neon matrix via codeposition of laser-evaporated beryllium atoms with O2 + CO/Ne. Doping by the heavier noble gas atoms argon, krypton and xenon yielded the associated adducts NgBeCO3 (Ng = Ar, Kr, Xe). The noble gas complexes have been identified via infrared spectroscopy. Quantum chemical calculations of NgBeCO3 and NgBeO (Ng = He, Ne, Ar, Kr, Xe) using ab initio methods and density functional theory show that the Ng-BeCO3 bonds are slightly longer and weaker than the Ng-BeO bonds. The energy decomposition analysis of the Ng-Be bonds suggests that the attractive interactions come mainly from the Ng → BeCO3 and Ng → BeO σ donation.

  5. Solar cycle variation of interstellar neutral He, Ne, O density and pick-up ions along the Earth's orbit

    CERN Document Server

    Sokół, Justyna M; Kubiak, Marzena A; Möbius, Eberhard

    2016-01-01

    We simulated the modulation of the interstellar neutral (ISN) He, Ne, and O density and pick-up ion (PUI) production rate and count rate along the Earth's orbit over the solar cycle from 2002 to 2013 to verify if solar cycle-related effects may modify the inferred ecliptic longitude of the ISN inflow direction. We adopted the classical PUI model with isotropic distribution function and adiabatic cooling, modified by time- and heliolatitude-dependent ionization rates and non-zero injection speed of PUIs. We found that the ionization losses have a noticeable effect on the derivation of the ISN inflow longitude based on the Gaussian fit to the crescent and cone peak locations. We conclude that the non-zero radial velocity of the ISN flow and the energy range of the PUI distribution function that is accumulated are of importance for a precise reproduction of the PUI count rate along the Earth orbit. However, the temporal and latitudinal variations of the ionization in the heliosphere, and particularly their varia...

  6. Measurement of the viscosities of He, Ne and Ar for the determination of their gas – kinetic diameters.

    Directory of Open Access Journals (Sweden)

    P.N. Ekemezie

    2015-11-01

    Full Text Available The viscosities of He, Ne and Ar gases were measured using pressure transducer to obtain the pressure, time data. Using the viscosity of dry air at the measured 320C ambient temperature, the evacuation data (pressure, time were converted to viscosity values thus: He (1.03 x 10-4 poise, Ne (1.72 x 10-4 poise, and Ar (1.96 x 10-4 poise. Finally, the collision diameter of the gases were calculated using appropriate equations to obtain He (0.19nm, Ne (0.22nm, and Ar (0.33nm. The values obtained were compared with those of literature (He = 0.21nm, Ne = 0.24nm, Ar = 0.36nm. Since the values of collision diameter obtained in this experiment are in conformity with those obtained from literature, we can safely conclude that measurement of collision diameter can be used as a quality assay for gases.

  7. Plasma density evolution in plasma opening switch obtained by a time-resolved sensitive He-Ne interferometer

    Science.gov (United States)

    Chen, Lin; Ren, Jing; Guo, Fan; Zhou, LiangJi; Li, Ye; He, An; Jiang, Wei

    2014-03-01

    To understand the formation process of vacuum gap in coaxial microsecond conduction time plasma opening switch (POS), we have made measurements of the line-integrated plasma density during switch operation using a time-resolved sensitive He-Ne interferometer. The conduction current and conduction time in experiments are about 120 kA and 1 μs, respectively. As a result, more than 85% of conduction current has been transferred to an inductive load with rise time of 130 ns. The radial dependence of the density is measured by changing the radial location of the line-of-sight for shots with the same nominal POS parameters. During the conduction phase, the line-integrated plasma density in POS increases at all radial locations over the gun-only case by further ionization of material injected from the guns. The current conduction is observed to cause a radial redistribution of the switch plasma. A vacuum gap forms rapidly in the plasma at 5.5 mm from the center conductor, which is consistent with the location where magnetic pressure is the largest, allowing current to be transferred from the POS to the load.

  8. Solar cycle variation of interstellar neutral He, Ne, O density and pick-up ions along the Earth's orbit

    Science.gov (United States)

    Sokół, Justyna M.; Bzowski, Maciej; Kubiak, Marzena A.; Möbius, Eberhard

    2016-06-01

    We simulated the modulation of the interstellar neutral (ISN) He, Ne, and O density and pick-up ion (PUI) production rate and count rate along the Earth's orbit over the solar cycle (SC) from 2002 to 2013 to verify if SC-related effects may modify the inferred ecliptic longitude of the ISN inflow direction. We adopted the classical PUI model with isotropic distribution function and adiabatic cooling, modified by time- and heliolatitude-dependent ionization rates and non-zero injection speed of PUIs. We found that the ionization losses have a noticeable effect on the derivation of the ISN inflow longitude based on the Gaussian fit to the crescent and cone peak locations. We conclude that the non-zero radial velocity of the ISN flow and the energy range of the PUI distribution function that is accumulated are of importance for a precise reproduction of the PUI count rate along the Earth orbit. However, the temporal and latitudinal variations of the ionization in the heliosphere, and particularly their variation on the SC time-scale, may significantly modify the shape of PUI cone and crescent and also their peak positions from year to year and thus bias by a few degrees the derived longitude of the ISN gas inflow direction.

  9. Injection-locking of two frequency-doubled lasers with 3.2 GHz offset for driving Raman transitions with low photon scattering in $^{43}$Ca$^+$

    CERN Document Server

    Linke, N M; Lucas, D M

    2013-01-01

    We describe the injection locking of two infrared (794 nm) laser diodes which are each part of a frequency doubled laser system. An acousto-optic modulator (AOM) in the injection path gives an offset of 1.6 GHz between the lasers for driving Raman transitions between states in the hyperfine split (by 3.2 GHz) ground level of $^{43}$Ca$^+$. The offset can be disabled for use in $^{40}$Ca$^+$. We measure the relative linewidth of the frequency-doubled beams to be 42 mHz in an optical heterodyne measurement. The use of both injection locking and frequency doubling combines spectral purity with high optical power. Our scheme is applicable for providing Raman beams across other ion species and neutral atoms where coherent optical manipulation is required.

  10. Low-energy helium-neon laser induces locomotion of the immature melanoblasts and promotes melanogenesis of the more differentiated melanoblasts: recapitulation of vitiligo repigmentation in vitro.

    Science.gov (United States)

    Lan, Cheng-Che E; Wu, Ching-Shuang; Chiou, Min-Hsi; Hsieh, Pei-Chen; Yu, Hsin-Su

    2006-09-01

    Helium-neon laser (He-Ne Laser, 632.8 nm) is a low-energy laser that has therapeutic efficacy on various clinical conditions. Our previous study has demonstrated efficacy of He-Ne laser on vitiligo, a disease characterized by skin depigmentation. To regain skin tone on vitiligo lesions, the process began by the migration of the immature melanoblasts (MBs) to the epidermis, which was followed by their functional development to produce melanin. In this study, we investigated the physiologic effects of He-Ne laser irradiation on two MB cell lines: the immature NCCmelb4 and the more differentiated NCCmelan5. The intricate interactions between MBs with their innate extracelluar matrix, fibronectin, were also addressed. Our results showed that He-Ne laser irradiation enhanced NCCmelb4 mobility via enhanced phosphorylated focal adhesion kinase expression and promoted melanogenesis in NCCmelan5. In addition, He-Ne laser decreased the affinity between NCCmelb4 and fibronectin, whereas the attachment of NCCmelan5 to fibronectin increased. The alpha5beta1 integrin expression on NCCmelb4 cells was enhanced by He-Ne laser. In conclusion, we have demonstrated that He-Ne laser induced different physiologic changes on MBs at different maturation stages and recapitulated the early events during vitiligo repigmentation process brought upon by He-Ne laser in vitro.

  11. Evaluation of probe lasers employed in optical diagnostics for phase transformation of thin films during excimer laser crystallization

    Science.gov (United States)

    Kuo, Chil-Chyuan

    2008-06-01

    The stability and reliability of probe laser is an important factor affecting the inspection of the phase transformation process of Si thin films during excimer laser crystallization using in-situ time-resolved optical measurements. The changes in 2D intensity profile, peak power density, and beam wander of the commonly used helium-neon (He-Ne) and diode laser are investigated experimentally. It is found that the peak power density of He-Ne laser is higher than that of diode laser, while the total power of He-Ne laser is lower than that of diode laser. Although the instability in the peak power density of He-Ne laser will increase with increasing the operation time, the beam stability of He-Ne laser is better than that of diode laser. For long-time operation (>24 h) of optical measurements, the diode laser is a good candidate of probe laser. Conversely, the diode laser is suitable for the short-time operation (<24 h) of optical measurements because the beam-wander is higher than that of He-Ne laser.

  12. Helium-neon laser irradiation stimulates cell proliferation through photostimulatory effects in mitochondria.

    Science.gov (United States)

    Hu, Wan-Ping; Wang, Jeh-Jeng; Yu, Chia-Li; Lan, Cheng-Che E; Chen, Gow-Shing; Yu, Hsin-Su

    2007-08-01

    Previous reports have shown that cellular functions could be influenced by visual light (400-700 nm). Recent evidence indicates that cellular proliferation could be triggered by the interaction of a helium-neon laser (He-Ne laser, 632.8 nm) with the mitochondrial photoacceptor-cytochrome c oxidase. Our previous studies demonstrated that He-Ne irradiation induced an increase in cell proliferation, but not migration, in the melanoma cell line A2058 cell. The aim of this study was to investigate the underlying mechanisms involved in photostimulatory effects induced by an He-Ne laser. Using the A2058 cell as a model for cell proliferation, the photobiologic effects induced by an He-Ne laser were studied. He-Ne irradiation immediately induced an increase in mitochondrial membrane potential (delta psi(mt)), ATP, and cAMP via enhanced cytochrome c oxidase activity and promoted phosphorylation of Jun N-terminal kinase (JNK)/activator protein-1 (AP-1) expressions. He-Ne irradiation-induced A2058 cell proliferation was significantly abrogated by the addition of delta psi(mt) and JNK inhibitors. Moreover, treatment with an He-Ne laser resulted in delayed effects on IL-8 and transforming growth factor-beta1 release from A2058 cells. These results suggest that He-Ne irradiation elicits photostimulatory effects in mitochondria processes, which involve JNK/AP-1 activation and enhanced growth factor release, and ultimately lead to A2058 cell proliferation.

  13. Experience of laser radiation for treatment of oral mucous lesions of different etiologies

    Science.gov (United States)

    Mosesyants, Elvira N.; Zazulevskaya, Lidiya Y.; Shevtsova, Elena

    1997-05-01

    Laser irradiation use for treatment of different manifestations of oral mucous diseases during the last 10 years. The aim of this research was study of the results of use He-Ne laser radiation in combination with main therapy for treatment of oral mucous lesions of different aetiology. He-Ne laser irradiation use for radiation of lesions were caused by different aetiology reasons. Under the observation was 116 patients 20 - 64 years old, who had and hadn't background pathology. There were biochemical, immunological controls. Data of research confirmed positive effect of use He-Ne laser radiation.

  14. Semiconductor laser applications in rheumatology

    Science.gov (United States)

    Pascu, Mihail-Lucian; Suteanu, S.

    1996-01-01

    Two types of laser diode (LD) based equipment for rheumatology are introduced. The first is a portable device which contains single LD emitting at 890 nm laser pulses (time full width 100 nsec) of reprate tunable within (0.5 - 1.5) kHz; the laser beam average power is 0.7 mW at 1 kHz reprate. The second is computer controlled, contains one HeNe laser and 5 LD allowing 6 modes of patient irradiation (placebo effect evaluation included). HeNe laser works in cw at 632.8 nm; the LD works each as described for the portable equipment. HeNe and LD beams are superposed so that HeNe laser spot in the irradiation plane has a 60 mm diameter and the LD spots covers a 50 mm diameter disc centered on the HeNe laser spot. Clinical applications using the second type of equipment are reported; 1287 patients were treated between October 1991 and October 1994. Female/male ratio was 4:1 and their age distribution was between 18 and 85 years. The average number of exposures was 10 and the mean exposure time was 7 minutes. Studies were made on the treatment of rheumatoid arthritis, seronegative arthritis, degenerative joint diseases, abarticular rheumatism, osteoporosis pain and pains and edema after fractures.

  15. [Experience in irradiating with helium-neon lasers to treat patients with relapsing aphthous stomatitis].

    Science.gov (United States)

    Prikuls, V F

    2000-01-01

    Seventy-five patients with relapsing aphthous stomatitis (41 with the fibrinous form, 25 with glandular form, and 9 with necrotic form) were treated using He-Ne laser and a photosensitizer. A good therapeutic effect was attained.

  16. Wave packet and statistical quantum calculations for the He + NeH{sup +} → HeH{sup +} + Ne reaction on the ground electronic state

    Energy Technology Data Exchange (ETDEWEB)

    Koner, Debasish; Panda, Aditya N., E-mail: adi07@iitg.ernet.in [Department of Chemistry, Indian Institute of Technology Guwahati, Guwahati 781039 (India); Barrios, Lizandra; González-Lezana, Tomás, E-mail: t.gonzalez.lezana@csic.es [Instituto de Física Fundamental, C.S.I.C., Serrano 123, Madrid 28006 (Spain)

    2014-09-21

    A real wave packet based time-dependent method and a statistical quantum method have been used to study the He + NeH{sup +} (v, j) reaction with the reactant in various ro-vibrational states, on a recently calculated ab initio ground state potential energy surface. Both the wave packet and statistical quantum calculations were carried out within the centrifugal sudden approximation as well as using the exact Hamiltonian. Quantum reaction probabilities exhibit dense oscillatory pattern for smaller total angular momentum values, which is a signature of resonances in a complex forming mechanism for the title reaction. Significant differences, found between exact and approximate quantum reaction cross sections, highlight the importance of inclusion of Coriolis coupling in the calculations. Statistical results are in fairly good agreement with the exact quantum results, for ground ro-vibrational states of the reactant. Vibrational excitation greatly enhances the reaction cross sections, whereas rotational excitation has relatively small effect on the reaction. The nature of the reaction cross section curves is dependent on the initial vibrational state of the reactant and is typical of a late barrier type potential energy profile.

  17. Electron loss to the continuum for H2(+) and He(+) ions colliding with H2, He, Ne and Ar. II - Absolute cross sections

    Science.gov (United States)

    Man, K. F.; Steckelmacher, W.; Lucas, M. W.

    1986-12-01

    Absolute cross sections for electron loss to the continuum (ELC) have been obtained for 0.8-2.8 MeV H2(+) and He(+) ions incident on H2, He, Ne, and Ar gases. The target consisted of a jet of gas from a multicapillary array, thereby providing a well localized and directed gas beam. A 30 deg parallel-plate analyzer having a FWHM resolution of (dE/E) = 0.001 was used to study the energy spectra of the ejected electrons as detected in a cone of solid angle 0.00156 sr about the forward direction. The cross sections were obtained by numerically integrating the ejected-electron velocity spectra over a width of 0.25 au on either side of the center of the cusp-shaped peak. When defined in this way the cross sections are found to decrease slowly with increasing projectile velocity, in agreement with an available theoretical calculation and other experimental results.

  18. Electron loss to the continuum for H2(+) and He(+) ions colliding with H(2), He, Ne and Ar. I - Electron cusp widths and shapes

    Science.gov (United States)

    Man, K. F.; Steckelmacher, W.; Lucas, M. W.

    1986-02-01

    Differential spectra for electron production in the forward direction have been obtained by collision of H2(+) and He(+) ions with H2, He, Ne, and Ar gases. The measurements were made with ions of energy 0.8-2.8 MeV. The target consisted of a jet of gas from a multicapillary array, thereby providing a well localized and directed gas beam. A 30 deg parallel-plate electrostatic analyzer having a FWHM resolution of 0.0001 was used to study the energy of the ejected electrons. A cusp-shaped peak centered on v(3) = v(i) was observed for all the electron spectra, suggesting that these electrons were ejected with only a small energy relative to the parent ions. This process has been called electron loss to the continuum (ELC) since in some ways it mimics the now well established phenomenon of charge exchange to the continuum (CEC). In contrast to data for ELC from heavy ions the cusps observed here were generally asymmetric. They did, however, show a width approximately independent of projectile velocity, a feature which seems to distinguish ELC from CEC. Both the cusp shapes and widths are compared with theoretical predictions and other experimental measurements.

  19. A two-Frequency RF Photocathode Gun

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, D.H. E-mail: dowell@slac.stanford.edu; Ferrario, M.; Kimura, T.; Lewellen, J.; Limborg, C.; Raimondi, P.; Schmerge, J.F.; Serafini, L.; Smith, T.; Young, L

    2004-08-01

    In this paper we resurrect an idea originally proposed by Serafini (Nucl. Instr. and Meth. A 318 (1992) 301) in 1992 for an RF photocathode gun capable of operating simultaneously at the fundamental frequency and a higher frequency harmonic. Driving the gun at two frequencies with the proper field ratio and relative phase produces a beam with essentially no RF emittance and a linear longitudinal phase space distribution. Such a gun allows a completely new range of operating parameters for controlling space charge emittance growth. In addition, the linear longitudinal phase space distribution aids in bunch compression. This paper will compare results of simulations for the two-frequency gun with the standard RF gun and the unique properties of the two-frequency gun will be discussed.

  20. A Two-Frequency RF Photocathode Gun

    Energy Technology Data Exchange (ETDEWEB)

    Dowell, D.

    2004-11-05

    In this paper we resurrect an idea originally proposed by Serafini[1] in 1992 for an RF photocathode gun capable of operating simultaneously at the fundamental frequency and a higher frequency harmonic. Driving the gun at two frequencies with the proper field ratio and relative phase produces a beam with essentially no rf emittance and a linear longitudinal phase space distribution. Such a gun allows a completely new range of operating parameters for controlling space charge emittance growth. In addition, the linear longitudinal phase space distribution aids in bunch compression. This paper will compare results of simulations for the two-frequency gun with the standard rf gun, and the unique properties of the two-frequency gun will be discussed.

  1. Microbiological estimate of parodontitis laser therapy efficiency

    Science.gov (United States)

    Mamedova, F. M.; Akbarova, Ju. A.; Bajenov, L. G.; Arslanbekov, T. U.

    1995-04-01

    In this work was carried out microbiological estimate the efficiency of ultraviolet and He-Ne laser radiation at the treatment of parodontitis. 90 persons was investigated with parodontitis of middle serious diagnosis. The optimal regimes of ultraviolet radiation influence on various micro-organisms discharged from pathologic tooth pocket (PTP) were determined. On the base of specils microflora composition study and data of microbic PTP dissemination owe may conclude that the complex He- Ne and ultraviolet laser radiation show the most pronounced antimicrobic effect.

  2. A Simple Laser Teaching Aid for Transverse Mode Structure Demonstration

    Science.gov (United States)

    Ren, Cheng; Zhang, Shulian

    2009-01-01

    A teaching aid for demonstrating the transverse mode structure in lasers is described. A novel device called "multi-dimension adjustable combined cat-eye reflector" has been constructed from easily available materials to form a He-Ne laser resonator. By finely adjusting the cat-eye, the boundary conditions of the laser cavity can be altered, which…

  3. 激光诱变选育耐高温耐酸乳酸菌%Screening of the thermotolerant aciduric lactic acid bacteria by He-Ne laser

    Institute of Scientific and Technical Information of China (English)

    崔国艳; 陈五岭; 周美红

    2012-01-01

    为获得耐温和耐酸性能优良的乳酸菌广泛应用于工业化生产,从不同地方采集的样品中分离筛选出一株耐高温乳酸菌株作为出发菌株,采用He-Ne激光对其进行诱变处理,对激光诱变参数进行优化,考察了突变株的耐温性、耐酸性和遗传稳定性.在波长632.8nm,功率10mW,照射时间15min条件下,经初筛、复筛获得1株耐高温且产酸能力强的优良菌株L-2,70℃培养突变株菌数量是出发菌株的9.4倍,菌数量多达15.56×108个/mL,突变株的酸度值最终可达3.42,且其具有良好的遗传稳定性.

  4. Controlled-Stress Large-Area Pulsed Laser Deposition of Yttria Stabilized Zirconia

    Science.gov (United States)

    2006-05-31

    a wide range of wavelengths from UV to IR. IR Carbon dioxide lasers, near–IR Nd:YAG lasers, HeNe red lasers, argon -ion green lasers, and UV excimer ...lines from argon , krypton, mercury, and xenon lamps . These lamps emitted light at multiple known wavelengths. The spectra from each lamp were

  5. Semiconductor laser

    Energy Technology Data Exchange (ETDEWEB)

    Ito, K.; Shyuue, M.

    1982-09-25

    A distributed feedback semiconductor laser is proposed which generates several beams with equal wavelengths in different directions. For this purpose, 1 millimeter grooves are cut into the surface of an n-type conductance GaAs plate in three different directions; these grooves form a diffraction grating. The center of this plate has no grooves and is bombarded by an He/Ne laser beam. The diffraction gratings provide resonance properties and generate laser beams with wavelengths of 8850, 9000 and 9200 angstroms.

  6. Numerical simulation for nuclear pumped laser

    Energy Technology Data Exchange (ETDEWEB)

    Sakasai, Kaoru [Japan Atomic Energy Research Inst., Tokyo (Japan)

    1998-07-01

    To apply nuclear pumped laser of {sup 3}He-Ne-Ar gas to detect neutron, the optimum gas mixture was investigated by numerical simulation. When {sup 3}He-Ne-Ar mixture gas are irradiated by neutron, proton and triton with high velocity are produced by {sup 3}He(np)T and two charge particles ionized {sup 3}He, Ne and Ar which reacted each other and attained to 3p`(1/2){sub 0}-3S`(1/2). The calculation method is constructed by defining the rate equations of each ion and exited atom and the electron energy balance equation and by time integrating the simultaneous differential equations of the above two equations and the law of conservation of charge. Penning ionization and energy transport by elastic collision of neutral atom were considered in the transport process of electron energy direct ionization by secondary charge particle. Calculation time was 1 msec. The optimum component was shown 3 atm He, 24 Torr He and 8 Torr Ar by simulation. Laser oscilation was generated under the conditions 3.3 x 10{sup 14} (N/cm{sup 2}/5) thermal neutron flux at 50 cm laser cell length and 99% coefficient of reflection of mirror. After laser oscilation, laser output was proportional to neutron flux. These results showed nuclear pumped laser of {sup 3}He-Ne-Ar was able to detect optically neutron. (S.Y)

  7. The effect of low-level helium-neon laser on oral wound healing

    Directory of Open Access Journals (Sweden)

    Farimah Sardari

    2016-01-01

    Conclusion: This study showed that He-Ne laser had no beneficial effects on incisional oral wound healing particularly in 5 days after laser therapy. Future research in the field of laser effects on oral wound healing in human is recommended.

  8. Molecular iodine fluorescence spectra generated with helium-neon lasers for spectrometer calibration.

    Science.gov (United States)

    Williamson, J Charles

    2010-12-01

    Gas-phase molecular iodine laser-induced fluorescence (LIF) spectra were recorded out to 815 nm at 1 cm(-1) resolution using green, yellow, and red helium-neon (HeNe) lasers as excitation sources. Nine previously unreported I(2) B←X absorption transitions accessed by these lasers were identified, and specific rovibronic transition assignments were made for two hundred LIF peaks--more than sixty per laser. These I(2) LIF peaks can be used to calibrate the vacuum wavenumber coordinate of spectrometers to better than 0.1 cm(-1) accuracy. In particular, green HeNe excitation of the I(2) R(106) 28-0 transition leads to strong fluorescence well suited for calibration, with a rotational doublet spacing of 15 cm(-1) and a doublet-to-doublet spacing of 190 cm(-1). Calibration by HeNe I(2) LIF may be an especially valuable technique for Raman spectroscopy applications.

  9. Investigation of laser fundamentals using a helium-neon laser

    Energy Technology Data Exchange (ETDEWEB)

    Jackson, M. [Department of Physics, University of Wisconsin-La Crosse, La Crosse, WI (United States); Bauen, A.D.; Hasbun, J.E. [Department of Physics, State University of West Georgia, Carrollton, GA (United States)

    2001-05-01

    Using an open-frame helium-neon (He-Ne) laser and optical spectrum analyser, students performed several upper-division laboratory experiments investigating important concepts regarding laser fundamentals. Such experiments include cavity stability (mirror geometry and thermal effects), longitudinal and transverse modes, free spectral range, and mode sweeping. In this paper we discuss, in an elementary way, the experimental procedures and results obtained. (author)

  10. Application of ring lasers to determine the directions to the poles of Earth's rotation

    Energy Technology Data Exchange (ETDEWEB)

    Golyaev, Yu D; Kolbas, Yu Yu [Open Joint-Stock Company ' M.F. Stel' makh Polyus Research and Development Institute' , Moscow (Russian Federation)

    2012-10-31

    Application of a ring laser to determine the directions to the poles of Earth's rotation is considered. The maximum accuracy of determining the directions is calculated, physical and technical mechanisms that limit the accuracy are analysed, and the instrumental errors are estimated by the example of ring He - Ne lasers with Zeeman biasing. (laser applications and other topics in quantum electronics)

  11. Electron loss to the continuum for H/sub 2//sup +/ and He/sup +/ ions colliding with H/sub 2/, He, Ne and Ar. 2. Absolute cross sections

    Energy Technology Data Exchange (ETDEWEB)

    Man, K.F.; Steckelmacher, W.; Lucas, M.W.

    1986-12-28

    Absolute cross sections for electron loss to the continuum have been obtained for 0.8-2.8 MeV H/sup +//sub 2/ and He/sup +/ ions incident on H/sub 2/, He, Ne and Ar gases. The target consisted of a jet of gas from a multicapillary array. A 30/sup 0/ parallel-plate analyser was used to study the energy spectra of the ejected electrons as detected in a cone of solid angle 1.56 x 10/sup -3/ sr about the forward direction. The cross sections were obtained by numerically integrating the ejected-electron velocity spectra over a width of 0.25 au on either side of the centre of the cusp-shaped peak. When defined in this way the cross sections are found to decrease slowly with increasing projectile velocity, in agreement with an available theoretical calculation and other experimental results.

  12. Laser phase-detector and counter for fine displacement measurement

    Science.gov (United States)

    Row, R. T.; Wang, C. P.

    A simple technique for the measurement of fine displacement has been developed. With use of an HeNe laser, an optical phase-detector, and counter, a displacement accuracy of 300 nm has been demonstrated over a range of 2 cm.

  13. Laser Micro-beam Manipulation System for Cells

    Institute of Scientific and Technical Information of China (English)

    孟祥旺; 李岩; 张书练; 张志诚; 赵南明

    2002-01-01

    This paper introduces a laser micro-beam system for cells manipulation. The laser micro-beam system comprises a laser scissors and a laser tweezers, which are focused by a Nd∶YAG laser and a He-Ne laser through a microscope objective, respectively. Not only the overall design of the laser micro-beam system is discussed, but also the design and choice of the critical components. A laser micro-beam system was constructed and anticipated experiment results were gained. Yeast cells can be successfully manipulated with the laser tweezers. Chromosomes can be successfully incised with the laser scissors.

  14. Endoscopic laser therapy of erosive-ulcerous and inflammatory damages of patients in oncological hospital

    Science.gov (United States)

    Efimov, Oleg N.; Kuvshinov, Yu. P.; Poddubny, Boris K.; Kartasheva, E. O.; Ungiadze, G. V.; Ponomarev, Igor V.; Mazurov, S. T.

    1996-01-01

    The results of laser therapy present in 374 patients with erosive-ulcerous and inflammatory damages of respiratory organs and of gastro-intestinal tract after oncological operations. Two types of laser namely endoscopic laser on the basis of He-Ne and Cu laser were used as sources of radiation. It was shown high therapeutic effectiveness of laser therapy. This method may be recommended for the above-mentioned category of the patients.

  15. High-power helium-neon laser irradiation inhibits the growth of traumatic scars in vitro and in vivo.

    Science.gov (United States)

    Shu, Bin; Ni, Guo-Xin; Zhang, Lian-Yang; Li, Xiang-Ping; Jiang, Wan-Ling; Zhang, Li-Qun

    2013-05-01

    This study explored the inhibitory effect of the high-power helium-neon (He-Ne) laser on the growth of scars post trauma. For the in vitro study, human wound fibroblasts were exposed to the high-power He-Ne laser for 30 min, once per day with different power densities (10, 50, 100, and 150 mW/cm(2)). After 3 days of repeated irradiation with the He-Ne laser, fibroblast proliferation and collagen synthesis were evaluated. For in vivo evaluation, a wounded animal model of hypertrophic scar formation was established. At postoperative day 21, the high-power He-Ne laser irradiation (output power 120 mW, 6 mm in diameter, 30 min each session, every other day) was performed on 20 scars. At postoperative day 35, the hydroxyproline content, apoptosis rate, PCNA protein expression and FADD mRNA level were assessed. The in vitro study showed that the irradiation group that received the power densities of 100 and 150 mW/cm(2) showed decreases in the cell proliferation index, increases in the percentage of cells in the G0/G1 phase, and decreases in collagen synthesis and type I procollagen gene expression. In the in vivo animal studies, regions exposed to He-Ne irradiation showed a significant decrease in scar thickness as well as decreases in hydroxyproline levels and PCNA protein expression. Results from the in vitro and in vivo studies suggest that repeated irradiation with a He-Ne laser at certain power densities inhibits fibroblast proliferation and collagen synthesis, thereby inhibits the growth of hypertrophic scars.

  16. Low-energy helium-neon laser therapy induces repigmentation and improves the abnormalities of cutaneous microcirculation in segmental-type vitiligo lesions.

    Science.gov (United States)

    Wu, Chieh-Shan; Hu, Stephen Chu-Sung; Lan, Cheng-Che E; Chen, Gwo-Shing; Chuo, Wen-Ho; Yu, Hsin-Su

    2008-04-01

    Segmental vitiligo (SV) is a special form of vitiligo occurring in a dermatomal distribution, and an abnormality involving the sympathetic nerves supplying the affected dermatome is known to underlie this disorder. Previously, we have shown that SV is associated with an abnormal increase in cutaneous blood flow and adrenoceptor responses in the affected areas. Since SV is resistant to conventional forms of therapy, its management represents a challenge for dermatologists. Low energy helium-neon lasers (He-Ne laser, wavelength 632.8 nm) have been employed as a therapeutic instrument in many clinical situations, including vitiligo management and repair of nerve injury. The purpose of this study was to evaluate the effectiveness and safety of He-Ne lasers in treating SV, and determine their effects on the repair of sympathetic nerve dysfunction. Forty patients with stable-stage SV on the head and/or neck were enrolled in this study. He-Ne laser irradiation was administered locally at 3.0 J/cm2 with point stimulation once or twice weekly. Cutaneous microcirculatory assessments in six SV patients were performed using a laser Doppler flowmeter. The sympathetic adrenoceptor response of cutaneous microcirculation was determined by measuring cutaneous blood flow before, during and after iontophoresis with sympathomimetic drugs (phenylephrine, clonidine and propranolol). All measurements of microcirculation obtained at SV lesions were simultaneously compared with contralateral normal skin, both before and after He-Ne laser treatment. After an average of 17 treatment sessions, initial repigmentation was noticed in the majority of patients. Marked repigmentation (> 50%) was observed in 60% of patients with successive treatments. Cutaneous blood flow was significantly higher at SV lesions compared with contralateral skin, but this was normalized after He-Ne laser treatment. In addition, the abnormal decrease in cutaneous blood flow in response to clonidine was improved by He-Ne

  17. Quantum theory and experimental study of laser polarization

    Energy Technology Data Exchange (ETDEWEB)

    Guo Siji; Gao Zhihui; Mao Huajin

    1987-02-01

    The full quantum theory of laser polarization is presented in this paper. The polarization properties of multimode laser beam in anisotropic cavity are analysed. Basic equations, calculation curve and polarization configurations of describing the inter-angle of mode polarization directions in 6328 A He-Ne laser vs. anisotropy are given. The effects of the phase anisotropy on mode polarization by stress is investigated. The experimental result and theory analysis is coincident.

  18. Investigations of the Rg-BrCl (Rg = He, Ne, Ar, Kr, Xe) binary van der Waals complexes: ab initio intermolecular potential energy surfaces, vibrational states and predicted pure rotational transition frequencies

    Science.gov (United States)

    Li, Song; Zheng, Rui; Chen, Shan-Jun; Chen, Yan; Chen, Peng

    2017-03-01

    The intermolecular potential energy surfaces (PESs) of the ground electronic state for the Rg-BrCl (Rg = He, Ne, Ar, Kr, Xe) van der Waals complexes have been constructed by using the coupled-cluster method in combination with the augmented quadruple-zeta correlation-consistent basis sets supplemented with an additional set of bond functions. The features of the anisotropic PESs for these complexes are remarkably similar, which are characterized by three minima and two saddle points between them. The global minimum corresponds to a collinear Rg-Br-Cl configuration. Two local minima, correlate with an anti-linear Rg-Cl-Br geometry and a nearly T-shaped structure, can also be located on each PES. The quantum bound state calculations enable us to investigate intermolecular vibrational states and rotational energy levels of the complexes. The transition frequencies are predicted and are fitted to obtain their corresponding spectroscopic constants. In general, the periodic trends are observed for this complex family. Comparisons with available experimental data for the collinear isomer of Ar-BrCl demonstrate reliability of our theoretical predictions, and our results for the other two isomers of Ar-BrCl as well as for other members of the complex family are also anticipated to be trustable. Except for the collinear isomer of Ar-BrCl, the data presented in this paper would be beneficial to improve our knowledge for these experimentally unknown species.

  19. Investigations of the Rg-BrCl (Rg=He, Ne, Ar, Kr, Xe) binary van der Waals complexes: ab initio intermolecular potential energy surfaces, vibrational states and predicted pure rotational transition frequencies.

    Science.gov (United States)

    Li, Song; Zheng, Rui; Chen, Shan-Jun; Chen, Yan; Chen, Peng

    2017-03-05

    The intermolecular potential energy surfaces (PESs) of the ground electronic state for the Rg-BrCl (Rg=He, Ne, Ar, Kr, Xe) van der Waals complexes have been constructed by using the coupled-cluster method in combination with the augmented quadruple-zeta correlation-consistent basis sets supplemented with an additional set of bond functions. The features of the anisotropic PESs for these complexes are remarkably similar, which are characterized by three minima and two saddle points between them. The global minimum corresponds to a collinear Rg-Br-Cl configuration. Two local minima, correlate with an anti-linear Rg-Cl-Br geometry and a nearly T-shaped structure, can also be located on each PES. The quantum bound state calculations enable us to investigate intermolecular vibrational states and rotational energy levels of the complexes. The transition frequencies are predicted and are fitted to obtain their corresponding spectroscopic constants. In general, the periodic trends are observed for this complex family. Comparisons with available experimental data for the collinear isomer of Ar-BrCl demonstrate reliability of our theoretical predictions, and our results for the other two isomers of Ar-BrCl as well as for other members of the complex family are also anticipated to be trustable. Except for the collinear isomer of Ar-BrCl, the data presented in this paper would be beneficial to improve our knowledge for these experimentally unknown species.

  20. Circumcision using CO2 laser: report of 860 cases

    Science.gov (United States)

    Chen, Wen B.; Chen, Zi-Fu; Zhan, Tian-qi; Gao, Xiang-Xun; Huang, Chao

    1993-03-01

    Eight-hundred-sixty cases of circumcision using CO2 laser are reported. The age of patients ranged from 9 - 65 years, with a mean age of 23.8 years. The technique was simple and can be quickly accomplished by a single operator. After local anesthesia the glans penis was protected by a protector. Then, circumcision was performed with a CO2 laser -- HeNe laser combined machine. There was an HeNe laser aiming system in this machine thus the surgeon had a three-dimensional visible indicator of the incision. The focusing CO2 laser beam was used for cutting the prepuce during the operation. There was almost no operative bleeding. All the patients needed no antibiotic postoperatively. Complications were minimal and satisfactory results were achieved.

  1. Effect of helium-neon and infrared laser irradiation on wound healing in rabbits

    Energy Technology Data Exchange (ETDEWEB)

    Braverman, B.; McCarthy, R.J.; Ivankovich, A.D.; Forde, D.E.; Overfield, M.; Bapna, M.S.

    1989-01-01

    We examined the biostimulating effects of helium-neon laser radiation (HeNe; 632.8 nm), pulsed infrared laser radiation (IR; 904 nm), and the two combined on skin wound healing in New Zealand white rabbits. Seventy-two rabbits received either (1) no exposure, (2) 1.65 J/cm2 HeNe, (3) 8.25 J/cm2 pulsed IR, or (4) both HeNe and IR together to one of two dorsal full-thickness skin wounds, daily, for 21 days. Wound areas were measured photographically at periodic intervals. Tissue samples were analyzed for tensile strength, and histology was done to measure epidermal thickness and cross-sectional collagen area. Significant differences were found in the tensile strength of all laser-treated groups (both the irradiated and nonirradiated lesion) compared to group 1. No differences were found in the rate of wound healing or collagen area. Epidermal growth was greater in the HeNe-lased area compared to unexposed tissue, but the difference was not significant. Thus, laser irradiation at 632.8 nm and 904 nm alone or in combination increased tensile strength during wound healing and may have released tissue factors into the systemic circulation that increased tensile strength on the opposite side as well.

  2. Low-energy laser treatment of rheumatic diseases: a long-term study

    Science.gov (United States)

    Antipa, Ciprian; Moldoveanu, Vladimir; Rusca, Nicolae; Bruckner, Ion I.; Podoleanu, Adrian Gh.; Stanciulescu, Viorica

    1995-05-01

    We tried to establish the efficiency of low energy (power) lasers (LEL), in various inflammatory and noninflammatory rheumatic diseases during five years. We treated 514 patients with osteoarthrosis, 326 patients with nonarticular rheumatism and 82 patients with inflammatory rheumatism, in four different ways: only with Galium-Aluminum-Arsenide (GaAs) infrared lasers; both GaAs lasers and Helium neon (HeNe) lasers; with placebo laser; with classical anti-inflammatory therapy. The results were analyzed using local objective improvements and the score obtained from a pain scale before and after the treatments. We also note some preliminary results obtained by the computer analysis of the evocated potentials after laser irradiation. We conclude that LEL (especially HeNe with GaAs) is obviously more efficient than placebo laser therapy and also had better or at least similar results, in most of the cases, than classical anti-inflammatory therapy.

  3. In vitro synthesis of prostaglandin E2 by synovial tissue after helium-neon laser radiation in rheumatoid arthritis.

    Science.gov (United States)

    Barberis, G; Gamron, S; Acevedo, G; Cadile, I; Juri, H; Campana, V; Castel, A; Onetti, C M; Palma, J A

    1996-08-01

    This paper reports the effect of helium-neon laser radiation (power of 5 mW and 632.8 nm wave length) on the synthesis of PGE2 in vitro in synovial tissue of biopsy samples of knee joints in patients with chronic rheumatoid arthritis stages II or III. Twelve patients were studied. Each patient received 15 applications of He-Ne laser. Eleven points for He-Ne laser applications were selected in one of the affected knees. The energy density used was 8 J/cm2 per application point. The He-Ne laser therapy reduced the synthesis of PGE2. The analysis of the data revealed a statistically significant difference between the levels of the synthesis of PGE2 before treatment (17.69 +/- 2.65 ng mg-1 of dry tissue h-1) and after treatment (13.85 +/- 2.73 ng mg-1 of dry tissue h-1), with p < 0.01 comparing mean values. This was also accompanied by relief of pain (91.6%), and a favorable subjective report from the patient. We conclude that PGE2 is a quantifiable parameter that could explain what causes pain relief in patients with rheumatoid arthritis that are treated with He-Ne laser.

  4. Laser wavelength comparison by high resolution interferometry.

    Science.gov (United States)

    Layer, H P; Deslattes, R D; Schweitzer, W G

    1976-03-01

    High resolution interferometry has been used to determine the wavelength ratio between two molecularly stabilized He-Ne lasers, one locked to a methane absorption at 3.39 microm and the other locked to the k peak of (129)I(2) at 633 nm. An optical beat frequency technique gave fractional orders while a microwave sideband method yielded the integer parts. Conventional (third derivative) peak seeking servoes stabilized both laser and cavity lengths. Reproducibility of the electronic control system and optics was a few parts in 10(12), while systematic errors associated with curvature of the cavity mirrors limited the accuracy of the wavelength ratio measurement to 2 parts in 10(10). The measured wavelength ratio of the methane stabilized He-Ne laser at 3.39 microm [P(7) line, nu(3) band] to the (129)I(2) (k peak) stabilized He-Ne laser at 633 nm was 5.359 049 260 6 (0.000 2 ppm). This ratio agrees with that calculated from the (lower accuracy) results of earlier wavelength measurements made relative to the (86)Kr standard. Its higher accuracy thus permits a provisional extension of the frequency scale based on the cesium oscillator into the visible spectrum.

  5. Research of Energy Density of He-Ne Laser in treatment of Tinnitus with Laser Meridian Points Therapy%耳鸣症激光经络穴位疗法氦-氖激光剂量对比研究

    Institute of Scientific and Technical Information of China (English)

    邱德明; 邱素兰

    2001-01-01

    本文首次报道,耳鸣症病人1035例1854只患耳、在激光经络穴位疗法(LMPT)治疗时,将每次每穴应用氦-氖激光的剂量(能量密度)随机分为A(9.555±1.911J/cm2)B、C、D(95.544±9.555J/cm2)E、F、G、H、I(257.958±9.555J/cm2)九个不同剂量的治疗观察组(每组115例205~208耳).结果疗效最理想者是D组,提示LMPT治疗耳鸣症采用氦-氖激光的最佳剂量为每次每穴投照95.544±9.555J/cm2,为医疗临床提供了指导性应用参数.

  6. Low-power Helium-Neon laser irradiation enhances the expression of VEGF in murine myocardium

    Institute of Scientific and Technical Information of China (English)

    张卫光; 吴长燕; 潘文潇; 田珑; 夏家骝

    2004-01-01

    Background Low-power helium-neon (He-Ne) lasers have been increasingly widely applied in the treatment of cardiovascular diseases, and its vasodilation effect has been proven. The aim of this study was to determine the effects of low-power He-Ne laser irradiation directed at the precardial region of Wistar rats on capillary permeability in the myocardium and the expression of myocardial vascular endothelial growth factor (VEGF). Methods Sixteen rats were divided randomly into control and irradiated groups (n=8, each). A He-Ne laser (632.8 nm) was applied to the irradiated group with a dose of 60.5 J/cm2. Ferritin was perfused into the left femoral vein and capillary permeability was examined under an electron microscope. VEGF expression in the myocardium was investigated by immunohistochemical methods, RT-PCR, and image analysis. Results The ultrastructures of the myocardial capillaries were examined. Compared to the control group, more high-density granules (ferritin), which were present within the capillary endothelium and the mitochondrions of myocardial cells in the internal layer of the myocardium, were observed in the irradiated group. VEGF staining of the myocardium was stronger in the irradiated group than that in the control group. The optic density of the irradiated group (0.246±0.015) was significantly higher than that of the control group (0.218±0.012, P<0.05). Finally, the levels of RT-PCR products of VEGF165 mRNA were 2.79 times higher in irradiated rats than in the control rats.Conclusions Our study demonstrates that He-Ne laser irradiation (in doses of 60.5 J/cm2) increases myocardial capillary permeability and the production of VEGF in myocardial microvessels and in myocardium. Our study provides experimental morphological evidence that myocardial microcirculation can be improved using He-Ne laser irradiation.

  7. Low-level laser therapy with helium-neon laser improved viability of osteoporotic bone marrow-derived mesenchymal stem cells from ovariectomy-induced osteoporotic rats

    Science.gov (United States)

    Fallahnezhad, Somaye; Piryaei, Abbas; Tabeie, Faraj; Nazarian, Hamid; Darbandi, Hasan; Amini, Abdoldllah; Mostafavinia, Ataroalsadat; Ghorishi, Seyed Kamran; Jalalifirouzkouhi, Ali; Bayat, Mohammad

    2016-09-01

    The purpose of this study was to evaluate the influences of helium-neon (He-Ne) and infrared (IR) lasers on the viability and proliferation rate of healthy and ovariectomy-induced osteoporotic (OVX) bone marrow mesenchymal stem cells (BMMSCs) in vitro. MSCs harvested from the BM of healthy and OVX rats were culture expanded. He-Ne and IR lasers were applied three times at energy densities of 0.6, 1.2, and 2.4 J/cm2 for BMMSCs. BMMSCs viability and proliferation rate were evaluated by MTT assay on days 2, 4, 6, 14, and 21. The results showed that healthy BMMSCs responded optimally to 0.6 J/cm2 using an IR laser after three times of laser radiation. Moreover, it was found that OVX-BMMSCs responded optimally to 0.6 J/cm2 with He-Ne laser and one-time laser radiation. It is concluded that the low-level laser therapy (LLLT) effect depends on the physiological state of the BMMSCs, type of the laser, wavelength, and number of laser sessions. The biostimulation efficiency of LLLT also depends on the delivered energy density. LLLT can enhance the viability and proliferation rate of healthy and especially osteoporotic autologous BMMSCs, which could be very useful in regenerative medicine.

  8. Low power laser irradiation does not affect the generation of signals in a sensory receptor

    Energy Technology Data Exchange (ETDEWEB)

    Lundeberg, T.; Zhou, J.

    1989-01-01

    The effect of low power Helium-Neon (He-Ne) and Gallium-Arsenide (Ga-As) laser on the slowly adapting crustacean stretch receptor was studied. The results showed that low power laser irradiation did not affect the membrane potential of the stretch receptor. These results are discussed in relation to the use of low power laser irradiation on the skin overlaying acupuncture points in treatment of pain syndrome.

  9. Induction of primitive pigment cell differentiation by visible light (helium-neon laser): a photoacceptor-specific response not replicable by UVB irradiation.

    Science.gov (United States)

    Lan, Cheng-Che E; Wu, Shi-Bei; Wu, Ching-Shuang; Shen, Yi-Chun; Chiang, Tzu-Ying; Wei, Yau-Huei; Yu, Hsin-Su

    2012-03-01

    Solar lights encompass ultraviolet (UV), visible, and infrared spectrum. Most previous studies focused on the harmful UV effects, and the biologic effects of lights at other spectrums remained unclear. Recently, lights at visible region have been used for regenerative purposes. Using the process of vitiligo repigmentation as a research model, we focused on elucidating the pro-differentiation effects induced by visible light. We first showed that helium-neon (He-Ne) laser (632.8 nm) irradiation stimulated differentiation of primitive pigment cells, an effect not replicable by UVB treatment even at high and damaging doses. In addition, significant increases of mitochondrial DNA copy number and the regulatory genes for mitochondrial biogenesis were induced by He-Ne laser irradiation. Mechanistically, we demonstrated that He-Ne laser initiated mitochondrial retrograde signaling via a Ca(2+)-dependent cascade. The impact on cytochrome c oxidase within the mitochondria is responsible for the efficacy of He-Ne laser in promoting melanoblast differentiation. Taken together, we propose that visible lights from the sun provide important environmental cues for the relatively quiescent stem or primitive cells to differentiate. In addition, our results also indicate that visible light may be used for regenerative medical purposes involving stem cells.

  10. Laser system for natural gas detection. Phase 1: Laboratory feasibility studies

    Science.gov (United States)

    Grant, W. B.; Hinkley, E. D., Jr.

    1982-01-01

    This project demonstrated the feasibility of using laser remote sensing technology as a tool for leak survey work in natural gas distribution systems. A laboratory device was assembled using a pair of helium neon (HeNe) lasers to measure methane. One HeNe laser emits radiation at a wavelength of 3.3922 micrometers, which corresponds to a strong absorption feature of methane, while the other emits radiation at a wavelength of 3.3911 micrometers, which corresponds to a weak absorption by methane. As a particular area is scanned for leaks, the laser is pointed at convenient topographic targets within its operating range, about 25 m. A portion of the backscattered radiation is collected by a receiver and focused onto an indium antimonide (InSb) photodetector, cooled to 77K. Methane concentrations were determined from the differential absorption at the two wavelengths for the backscattered radiation.

  11. Clinical observation of laser treatment of cholelithiasis in 105 cases

    Science.gov (United States)

    Wang, Guang-hua; Gu, Xi-rong; Chen, Bin-jun; Xia, Guo-pin

    1993-03-01

    This paper reports the results of non-operative therapy for cholelithiasis in 105 cases using He-Ne laser lithotripsy and a high fat diet, as well as Chinese and Western medicine. There were 32 male and 73 female patients ages 11 - 67 years (with an average of 41.2 years). All cases were confirmed by either B mode sonography or cholangiography. This paper presents the technique of treatment, its indications, contraindications, and therapeutic results. The results reveal a cure rate of 20% (21/105), satisfactory in 72.4% (76/105), and failed in 7.6% (8/105). Successful passage of gallstones was found in 92.4% and 52 samples of gallstones were examined qualitatively. The results show that He-Ne laser irradiation in the treatment of cholelithiasis is associated with neither pain, side-effect, nor cross infection, and is readily accepted by the patients.

  12. [Experimental study of effect of low power laser on telomere length of cells].

    Science.gov (United States)

    Huang, Ling; Wu, Zhihui; Mo, Hua

    2013-06-01

    To investigate the effect of low power helium neon laser (He-Ne laser) on the telomere length of human fetal lung diploid fibroblast (2BS) cell, we used the laser (gamma = 632. 8 nm, P = 2 mW) to treat the young 2BS cells. Cell growth and proliferation was observed through MTT method after treating with low power laser. The relative telomere length of 2BS cells was detected by fluorescence real-time quantitative PCR (q-PCR). The results showed that the cells of the treated groups grew better than the untreated groups. The telomere DNA length of the old 2BS cells, treated by low power He-Ne laser when they were young, was longer than that of untreated group. The results of the present study indicated that the low power He-Ne laser might decrease shortening rate of telomere and delay the aging of cells. Therefore, this study provides the experimental basis for us to further investigate the effect of low power laser on cell aging at the gene level.

  13. K-M模型下的人全血对He-Ne激光的散射与吸收特性%Scattering and Absorbing Characteristics of Human Whole Blood in K-M Model at He-Ne Laser in Vitro

    Institute of Scientific and Technical Information of China (English)

    冯尚源; 刘丽娜; 陈荣; 谢树森; 彭东青

    2003-01-01

    研究了人全血对He-Ne激光的反射和透射传输特性.实验采用单积分球系统及波长为632.8 nm的He-Ne激光器,采用Kubelka-Munk模型分析和计算了不同血液样品的吸收系数、散射系数及总光强I(x)随厚度的变化情况.结果表明:K-M模型结合单积分球系统的测量方法可用于研究血液样品光学参数,不同类型的血液样品在K-M模型下的吸收系数或散射系数有差别,散射系数的差异较小,有3例胃癌患者血液的吸收系数与正常人有较大差异.

  14. Kubelka Munk模型下人静脉组织的光学特性%Optical Characteristics of Human Veins Tissue in Kubelka-Munk Model at He-Ne Laser in Vitro

    Institute of Scientific and Technical Information of China (English)

    许静芬; 魏华江; 李晓原; 巫国勇; 魏冬季

    2002-01-01

    本文测量了人静脉对He-Ne激光的反射和透射传输特性.实验采用两积分球系统和波长为632.8 nm的He-Ne激光器,并根据测量数据及采用Kubelka-Munk(K-M)模型分析和计算了人静脉组织对该波长激光的吸收系数、散射系数及总的光强I(x)及前向散射通量i(x)和后向散射通量j(x)的变化情况.结果表明,不同的静脉组织的漫反射率和透射率有明显差别;对激光的吸收系数和散射系数也有明显的不同;I(x)、i(x)和j(x)的变化情况也有明显的区别.

  15. The EM Observation on the Myelinated Nerve Fiber of Macrobrachium rosenbergii Radiated by He-Ne Laser%He-Ne激光照射罗氏沼虾腹髓鞘神经纤维的电镜观察

    Institute of Scientific and Technical Information of China (English)

    姚泊; 黄丽宜; 曹爱娣; 梁美玉

    2005-01-01

    用He-Ne激光照射罗氏沼虾(Macrobrachium rosenbergii)的腹髓鞘神经纤维,结果表明,神经胶质细胞为不规则形,核的一端较大,另一端分叉,半包裹着轴突,呈蝴蝶形,核的横轴直径为3.07μm, 轴突直径为1.53 μm;在髓鞘中普遍出现增厚的膜层结构,且膜层结构厚薄不一,具有高嗜锇性、电子密度大,正常的膜层厚度为33.33 nm,增厚的膜层厚度可达100 nm.在两膜层之间存在着许多颗粒状物质.

  16. 激光诱变选育耐酸产氢菌产气肠杆菌%Screening of hydrogen-producing aciduric Enterobacter aerogenes strain using He-Ne laser irradiation

    Institute of Scientific and Technical Information of China (English)

    卢文玉; 闻建平; 陈宇; 刘铭辉

    2006-01-01

    运用He-Ne激光辐照产气肠杆菌(Enterobacter aerogenes),对激光诱变参数进行优化,考察了突变株的遗传稳定性、耐酸性和产氢特性.结果筛选到一株遗传性状稳定的高产氢突变株,具有良好的耐酸性,在pH值3.0时仍能生长.通过间歇实验,产氢量和产氢速率分别达到1781 mL/L和240 mL/(L·h),比原始菌分别提高了48%和32%.说明该He-Ne激光诱变育种技术可以在产氢微生物领域中应用.

  17. Investigation of two-frequency Paul traps for antihydrogen production

    Energy Technology Data Exchange (ETDEWEB)

    Leefer, Nathan; Krimmel, Kai, E-mail: kkrimmel@students.uni-mainz.de [Helmholtz-Institut Mainz (Germany); Bertsche, William [University of Manchester (United Kingdom); Budker, Dmitry [Helmholtz-Institut Mainz (Germany); Fajans, Joel [University of California at Berkeley, Department of Physics (United States); Folman, Ron [Ben-Gurion University of the Negev, Department of Physics (Israel); Häffner, Hartmut [University of California at Berkeley, Department of Physics (United States); Schmidt-Kaler, Ferdinand [Helmholtz-Institut Mainz (Germany)

    2017-11-15

    Radio-frequency (rf) Paul traps operated with multifrequency rf trapping potentials provide the ability to independently confine charged particle species with widely different charge-to-mass ratios. In particular, these traps may find use in the field of antihydrogen recombination, allowing antiproton and positron clouds to be trapped and confined in the same volume without the use of large superconducting magnets. We explore the stability regions of two-frequency Paul traps and perform numerical simulations of small samples of multispecies charged-particle mixtures of up to twelve particles that indicate the promise of these traps for antihydrogen recombination.

  18. [Treatment of lacrimal duct diseases using low energy helium-neon laser].

    Science.gov (United States)

    Dushin, N V; Azibekian, A B; Ali Akhsan, M

    2002-01-01

    Treatment of diseases of the lacrimal duct remains a pressing problem in ophthalmology. These diseases are responsible for 71-85.4% diseases in capable people. Sixty patients with chronic dacryocystitis with partially retained patency of the lacrimal duct were treated by He-Ne low-frequency laser ULF-01 (output power 6.10 mcWt, laser beam wave length 0.632 nm). The patients received 3-5 min sessions twice a week, 5-8 sessions per course. Positive effect was attained in 56 patients: complete cessation of excessive lacrimal discharge in 38 patients and subjective improvement in 18. He-Ne laser exposure brings about a good antiinflammatory effect; in combination with antibiotic therapy it promotes rapid sanitization of the lacrimal duct, removes edema, and rapidly normalizes lacrimal discharge.

  19. Tunable diode laser control by a stepping Michelson interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Valentin, A.; Nicolas, C.; Henry, L.; Mantz, A.W.

    1987-01-01

    A tunable diode laser beam is sent through a Michelson interferometer and is locked to a fringe of the diode laser interferometer pattern by controlling the diode laser polarization current. The path difference change of the Michelson interferometer is controlled step by step by a stabilized He--Ne red laser. When the interferometer path differences increases or decreases, the polarization current of the diode is forced to change in order to preserve the interference order of the diode beam. At every step the diode frequency is accurately fixed and its phase noise significantly reduced.

  20. Measuring the Virgo area tilt noise with a laser gyroscope

    CERN Document Server

    Belfi, Jacopo; Bosi, Filippo; Carelli, Giorgio; Di Virgilio, Angela; Maccioni, Enrico; Stefani, Fabio

    2011-01-01

    We report on the measurements of tilt noise performed at the Virgo site with a ring laser gyroscope. The apparatus is a He-Ne laser operating in a square cavity mounted on a vertical plane perpendicular to the north-south arm of the inteferometer. We discuss the possibility of using the ring laser signal to improve the performances of the control system of the Virgo seismic suspensions. The comparison between the ring laser signal and the control signals for the longitudinal translations of the inverted pendulum (IP) shows remarkable coherence in the frequency range 20-200 mHz.

  1. Changes in the germination process and growth of pea in effect of laser seed irradiation

    Science.gov (United States)

    Podleśna, Anna; Gładyszewska, Bożena; Podleśny, Janusz; Zgrajka, Wojciech

    2015-10-01

    The aim of this study was to determine the effect of pre-sowing helium-neon (He-Ne) laser irradiation of pea seeds on changes in seed biochemical processes, germination rate, seedling emergence, growth rate, and yield. The first experimental factor was exposure to laser radiation: D0 - no irradiation, D3 - three exposures, D5 - five exposures, and the harvest dates were the second factor. Pre-sowing treatment of pea seeds with He-Ne laser light increased the concentrations of amylolytic enzymes and the content of indole-3-acetic acid (IAA) in pea seeds and seedlings. The exposure of seeds to He-Ne laser light improved the germination rate and uniformity and modified growth stages, which caused acceleration of flowering and ripening of pea plants. Laser light stimulation improved the morphological characteristics of plants by increasing plant height and leaf surface area. Irradiation improved the yield of vegetative and reproductive organs of pea, although the effects varied at the different growth stages. The increase in the seed yield resulted from a higher number of pods and seeds per plant, whereas no significant changes were observed in the number of seeds per pod. Both radiation doses exerted similarly stimulating effects on pea growth, development, and yield.

  2. Testing relativity again, laser, laser, laser, laser

    NARCIS (Netherlands)

    Einstein, A.

    2015-01-01

    laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser, laser,

  3. The clinical application of laser in otorhinolaryngology

    Science.gov (United States)

    Meng, Guo Zhen; Meng, Zhao-He; Zhang, Zhi Hua

    2005-07-01

    Objective: The paper presented the current application of laser in Otolaryngology in our hospital. Methods: We have applied the carbon dioxide, the YAG, the He-Ne and the Ho:YAG lasers to coagulate or vaporize treated Otolaryngology disease. Results: After treatment, we have a satisfying result. Conclusion: The paper presented the current application of laser respectively in otology, rhinology and pharynolaryngology and some representative of the treated diseases. It also demonstrated that long-term effectiveness of some diseases, such as allergic rhinitis and laryngeal stenosis treated by laser was not satisfying and further studies were expected, laser excision of tonsile was only used in the cases which traditional tonsillectomy was not available. Therefore, to improve clinical laser application greatly, further more research works and cooprations between investors of laser instrument and surgeons of oto-laryngology were necessary. Theory and Clinics of laser application should be improved also.

  4. Penning neon plasma laser pumped by a compact accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Derzhiev, V.I.; Zhidkov, A.G.; Koval' , A.V.; Skakun, V.S.; Tarasenko, V.F.

    1988-01-01

    A study is made of the emission characteristics of a neon laser (wavelengths, 585.3, 724.5, and 703.2 nm) in the afterglow (50-120 ns) of a plasma generated by a short (less than 10 ns) electron beam pulse (20-100 A/sq cm) during the longitudinal and transverse pumping of dense (0.5-3 atm) He-Ne-Ar(Kr) and Ne-H2 mixtures. It is shown experimentally that preheating has a negative effect on the lasing characteristics. The relaxation kinetics of the He-Ne-Ar mixture and the emission characteristics of the neon yellow line are calculated; the results are in good agreement with measured lasing characteristics. 7 references.

  5. Monitoring the effect of low-level laser therapy in healing process of skin with second harmonic generation imaging techniques

    Science.gov (United States)

    Zhang, Xiaoman; Yu, Biying; Weng, Cuncheng; Li, Hui

    2014-11-01

    The 632nm wavelength low intensity He-Ne laser was used to irradiated on 15 mice which had skin wound. The dynamic changes and wound healing processes were observed with nonlinear spectral imaging technology. We observed that:(1)The wound healing process was accelerated by the low-level laser therapy(LLLT);(2)The new tissues produced second harmonic generation (SHG) signals. Collagen content and microstructure differed dramatically at different time pointed along the wound healing. Our observation shows that the low intensity He-Ne laser irradiation can accelerate the healing process of skin wound in mice, and SHG imaging technique can be used to observe wound healing process, which is useful for quantitative characterization of wound status during wound healing process.

  6. High-frequency signal generation using 1550 nm VCSEL subject to two-frequency optical injection

    Science.gov (United States)

    Consoli, Antonio; Quirce, Ana; Valle, Angel; Esquivias, Ignacio; Pesquera, Luis; García Tijero, Jose Manuel

    2013-03-01

    We experimentally investigate high-frequency microwave signal generation using a 1550 nm single-mode VCSEL subject to two-frequency optical injection. We first consider a situation in which the injected signals come from two similar VCSELs. The polarization of the injected light is parallel to that of the injected VCSEL. We obtain that the VCSEL can be locked to one of the injected signals, but the observed microwave signal is originated by beating at the photodetector. In a second situation we consider injected signals that come from two external cavity tunable lasers with a significant increase of the injected power with respect to the VCSEL-by-VCSEL injection case. The polarization of the injected light is orthogonal to that of the free-running slave VCSEL. We show that in this case it is possible to generate a microwave signal inside the VCSEL cavity.

  7. Semiconductor lasers in rheumatological treatment

    Science.gov (United States)

    Pascu, Mihail-Lucian; Suteanu, S.; Ignat, P.; Pruna, Simion; Chitu, A.

    1995-03-01

    A computer controlled equipment, containing 6 lasers (HeNe and 5 diode lasers--DL) conceived to be used in rheumatological treatment is reported. DL emit at 895 nm and for typical applications, their expanded spots are superposed within the irradiation plane, on the HeNE defocused spot used to define the surface to be irradiated. DL emit 100 nsec pulses between 0.5 KHz and 1.5 KHz repetition rate and 0.5 mW average power (measured at 1 KHz). 150 patients with rheumathologic diseases were treated: lumbar spondylosis (75), gonarthrosis (30), cervical spondylosis (21), coxarthrosis (15), Heberden and Bouchard (9). The treatment consisted of: group I, 50 patients--laser therapy, 10 min/day, 10 days; group II, 50 patients--classical antirheumatic treatment; group III, 50 patients--mixed treatment. Assessment of sympathetic skin activity made using reactometry measurements, shows that latency time was longer before irradiation, 1867 +/- 289) msec then after, (1234 +/- 321) msec. Pain rating indexes decreasing for all three groups of patients were measured. Better results for more superficial diseases were obtained and best results were observed after irradiation with 1 KHz - 1.5 KHz repetition rate IR pulses. Better results were obtained when spot irradiation in a few points combined with zone irradiations was used.

  8. Laser Biostimulation Of Wound Healing In Arteriopatic Patients

    Science.gov (United States)

    Tallarida, G.; Baldoni, F.; Raimondi, G.; Massaro, M.; Peruzzi, G.; Bertolotti, M.; Ferrari, A.; Scudieri, F.

    1981-05-01

    Low-power laser irradiation has been employed in the attempt to accelerate the wound-healing of ischemic cutaneous ulcerations with threatening or manifest gangrene due to arteriosclerosis obliterans of the lower limbs. Irradiation was performed by using a low-power He-Ne gas laser of 6328 Å wavelength and was concentrated at the peripheral zone of the lesions. The preliminary results of the study indicate that laser stimulation might be new approach in the conservative menagement of the ischemic ulcers in patients with severe peripheral obstructive arteriopaties not suited for arterial reconstruction.

  9. Microprocessor-controlled laser tracker for atmospheric sensing

    Science.gov (United States)

    Johnson, R. A.; Webster, C. R.; Menzies, R. T.

    1985-01-01

    An optical tracking system comprising a visible HeNe laser, an imaging detector, and a microprocessor-controlled mirror, has been designed to track a moving retroreflector located up to 500 m away from an atmospheric instrument and simultaneously direct spectrally tunable infrared laser radiation to the retroreflector for double-ended, long-path absorption measurements of atmospheric species. The tracker has been tested during the recent flight of a balloon-borne tunable diode laser absorption spectrometer which monitors the concentrations of stratospheric species within a volume defined by a 0.14-m-diameter retroreflector lowered 500 m below the instrument gondola.

  10. Low Level Laser Irradiation of Nerve Cells In Vitro

    Science.gov (United States)

    1996-01-01

    significant difference reported. Rochkind et al. has published a series of articles on the effects of the HeNe low level laser on induced nerve injuries...been inconclusive. An example of all this relative confusion can be seen in articles on nerve regeneration subsequent to crush injury in the rat model...findings. Lasers Surg Med, 9(1): 1-5, 1989. 20. Kitchen, S.S., Partridge, C.J.: A review of low level laser therapy Part I, 11, and III. Physiotherapy

  11. Photodynamic action of laser radiation and methylene blue on some opportunistic microorganisms of the oral cavity

    Science.gov (United States)

    Ivanov, Krill I.; Titorenko, Vladimir A.; Shoub, Gennady M.; Lepilin, Alexander V.; Ovchinnikov, Ilya S.; Mischenko, Oksana S.; Tuchin, Valery V.

    2000-03-01

    We have studied photodynamic action of He-Ne laser radiation on cultures of Staphylococcus (strain 209 P), Streptococcus anhaemolyticus, and total microflora of dental deposit been sensitized by methylene blue. The concentration of the dye was varied from 0.001% to 0.1%, radiation power density was 100 mW/cm2. Irradiated strain was put into thermostat for 24 hours, then the number of colonies was counted and analyzed.

  12. Treatment of TMJDS with helium-neon laser beam irradiation on the acupoints

    Science.gov (United States)

    Li, Ping

    1993-03-01

    Through He-NE laser stimulation of acupuncture points, we treated and observed 50 cases of Temporomandibular Joint Dysfunction Syndrome (TMJDS). The results proved that this treatment was very effective for relieving the patient's pain. In cases which had structural disturbances and organic damage such as limitation of mouth-opening and joint clink, there was less improvement of symptoms and no relief for joint clink.

  13. Laser Doppler flowmetry imaging

    Science.gov (United States)

    Nilsson, Gert E.; Wardell, Karin

    1994-02-01

    A laser Doppler perfusion imager has been developed that makes possible mapping of tissue blood flow over surfaces with extensions up to about 12 cm X 12 cm. The He-Ne laser beam scans the tissue under study throughout 4096 measurement sites. A fraction of the backscattered and Doppler broadened light is detected by a photo diode positioned about 20 cm above the tissue surface. After processing, a signal that scales linearly with perfusion is stored in a computer and a color coded image of the spatial tissue perfusion is shown on a monitor. A full format scan is completed in about 4.5 minutes. Algorithms for calculating perfusion profiles and averages as well as substraction of one image from another, form an integral part of the system data analysis software. The perfusion images can also be exported to other software packages for further processing and analysis.

  14. In Situ Mitigation of Subsurface and Peripheral Focused Ion Beam Damage via Simultaneous Pulsed Laser Heating.

    Science.gov (United States)

    Stanford, Michael G; Lewis, Brett B; Iberi, Vighter; Fowlkes, Jason D; Tan, Shida; Livengood, Rick; Rack, Philip D

    2016-04-01

    Focused helium and neon ion (He(+)/Ne(+)) beam processing has recently been used to push resolution limits of direct-write nanoscale synthesis. The ubiquitous insertion of focused He(+)/Ne(+) beams as the next-generation nanofabrication tool-of-choice is currently limited by deleterious subsurface and peripheral damage induced by the energetic ions in the underlying substrate. The in situ mitigation of subsurface damage induced by He(+)/Ne(+) ion exposures in silicon via a synchronized infrared pulsed laser-assisted process is demonstrated. The pulsed laser assist provides highly localized in situ photothermal energy which reduces the implantation and defect concentration by greater than 90%. The laser-assisted exposure process is also shown to reduce peripheral defects in He(+) patterned graphene, which makes this process an attractive candidate for direct-write patterning of 2D materials. These results offer a necessary solution for the applicability of high-resolution direct-write nanoscale material processing via focused ion beams.

  15. [Changes in the blood rheological properties in the transcutaneous irradiation of the ulnar vascular fascicle with a helium-neon laser].

    Science.gov (United States)

    Paleev, N R; Karandashov, V I; Voronina, M A; Fin'ko, I A

    1993-10-01

    An investigation of blood rheologic properties in 12 patients with acute pneumonia has been made by using low-energy He-Ne laser (LG-79-2) irradiation of vascular fascicle. 37 exposures have been performed, 40 min each. Immediate effects of He-Ne laser were studied comparing blood samples taken before and after the radiation. Results obtained have demonstrated transcutaneous blood irradiation causing prompt and pronounced effects on blood rheologic characteristics: reduced blood viscosity, improved both viscous-elastic properties and osmotic resistance of erythrocytes, activated platelet aggregation. These effects excluding the latter are rather positive for the human body. As for platelet aggregation, its activation following transcutaneous laser irradiation of blood might be expected to grow into a factor of risk provoking pathologic thrombogenesis in venous congestion, hypercoagulation and vascular wall injury.

  16. Micrograting Polymerization Fabrication with a Single Femtosecond Laser Pulse at 400 nm Wavelength

    Institute of Scientific and Technical Information of China (English)

    郭红沧; 郭亨长; 蒋红兵; 杨宏; 龚旗煌; 王涛; 施盟泉; 吴飞鹏

    2003-01-01

    High diffraction efficiency refractive index-modulated holographic micrograting on a polymer thin film was obtained with a single femtosecond laser pulse interference and photo-polymerization. The diffractive efficiency of the micrograting with an He-Ne laser is up to 78% when the thickness of the film is 90 μm, which corresponds to the refractive index-modulation as large as 2.4 × 10-3. The compared experiment with a femtosecond oscillator laser indicated that a single femtosecond Iaser pulse has the advantages in laser machining over the cw holography method such as high fabrication speed, good surface structure and high diffractive efficiency.

  17. A laser feedback control design for passive ring laser gyros in a very high finesse cavity

    Science.gov (United States)

    Lorenz, M. A.

    1985-12-01

    The Frank J. Seiler Research Laboratory is currently developing a Passive Resonant Ring Laser Gyroscope (PRRLG) enclosing 58 sq m for proposed use in testing high precision rate sensors and for possibly validating the Theory of General Relativity. The sensitivities required for such experiments are in the 10 to the minus 7th power to 10 to the minus 10th power Earth Rate Unit (ERU) range. This high sensitivity necessitates the use of a large, high finesse cavity. In dealing with high finesse cavities new considerations arise. For example, the cavity linewidth is narrower than linewidths of commercially available stabilized He-Ne lasers. The stability of the laser then becomes the limiting factor in the performance of the PRRLG because of the increased signal-to-noise ratio that arises in this situation. In addition, high finesse cavities exhibit photon lifetimes on the order of 10 to the minus 3rd power to 10 to the minus 6th power seconds, which limits the bandwidth of practical controllers. In this research, a PRRLG was constructed in which a He-Ne laser was frequency locked to 25,000 finesse, 169 sq. cm. resonant cavity, as opposed to the more traditional technique of locking the resonant condition of the cavity to the laser frequency.

  18. Bibliography of Soviet Laser Developments, Number 52, March - April 1981.

    Science.gov (United States)

    1982-05-17

    of patients with rheumatoid arthritis . VKFLFK, no. 6, 1980, 17-20. 266. Il’yasova, Sh.G., and M.F. Popova (602). Effect of He-Ne laser beams on the...no. 6, 1980, 22-24. 273. Krylov, O.A. (605). Ways of studying the mechanism of the action of laser irradiation [in physiotherapy . VKFLFK, no. 6, 1980...Orthopedics (Kazanskiy NII travmatologii i ortopedii). 605. Central Institute of Health Resort Treatment and Physiotherapy , Moscow (Tsentral’nyy institut

  19. Effects of low-power laser irradiation (LPLI) at different wavelengths and doses on oxidative stress and fibrogenesis parameters in an animal model of wound healing.

    Science.gov (United States)

    Silveira, Paulo Cesar Lock; Silva, Luciano A; Freitas, Tiago P; Latini, Alexandra; Pinho, Ricardo A

    2011-01-01

    Gallium-arsenide (GaAs) and helium-neon (HeNe) lasers are the most commonly used low-energy lasers in physiotherapy for promoting wound healing and pain modulation. The aim of this study was investigate the effect of low-power laser irradiation (LPLI) at different wavelengths and doses on oxidative stress and fibrogenesis parameters in an animal model of wound healing. The animals were randomly divided into five groups (n=6): Controls (skin injured animals without local or systemic treatment), skin injury treated with HeNe 1 J/cm(2) (two seg); skin injury treated with HeNe 3 J/cm(2) (six seg); skin injury treated with GaAs 1 J/cm(2) (three seg); skin injury treated with GaAs 3 J/cm(2) (nine seg). A single circular wound measuring 8 mm in diameter was surgically created on the back of the animal. The rats were irradiated at 2, 12, 24, 48, 72, 96, and 120 h after skin injury. The parameters, namely hydroxyproline content, activities of the antioxidant enzymes superoxide dismutase (SOD) and catalase (CAT), and lipid (TBARS) and protein oxidation (carbonyl groups) measurements were assessed. In addition, wound size regression was also analyzed. The results showed an improvement in the wound healing reflected by the reduction in wound size and increased collagen synthesis. Moreover, a significant reduction in TBARS levels, carbonyl content, and SOD and CAT activities were observed after laser irradiation, particularly with the treatments HeNe laser 1 and 3 J/cm(2) dose and GaAs 3 J/cm(2) dose. The data strongly indicate that LPLI therapy is efficient in accelerating the skin wound healing process after wounding, probably by reducing the inflammatory phase and inducing collagen synthesis.

  20. Laser illuminated flat panel display

    Energy Technology Data Exchange (ETDEWEB)

    Veligdan, J.T.

    1995-12-31

    A 10 inch laser illuminated flat panel Planar Optic Display (POD) screen has been constructed and tested. This POD screen technology is an entirely new concept in display technology. Although the initial display is flat and made of glass, this technology lends itself to applications where a plastic display might be wrapped around the viewer. The display screen is comprised of hundreds of planar optical waveguides where each glass waveguide represents a vertical line of resolution. A black cladding layer, having a lower index of refraction, is placed between each waveguide layer. Since the cladding makes the screen surface black, the contrast is high. The prototype display is 9 inches wide by 5 inches high and approximately I inch thick. A 3 milliwatt HeNe laser is used as the illumination source and a vector scanning technique is employed.

  1. Biostimulative Effect Of Laser Beams

    Science.gov (United States)

    Mester, E.

    1981-05-01

    We report on experiences gained in healing clinical cases treated with He-Ne and Argon-laser grouped according to etiology. In order to elucidate the action mechanism of the bioregulatory process, the following experiments were carried out: 1. Serial electron-microscopic and radioactivity studies of samples obtained from human ulcers; 2. Chemical transfer of stimulating substrate on human leukocyte population; 3. Enzyme histochemical studies in experiments on rats; 4. Study of vascularization with the "ear chamber" technique carried out on rabbit's ear; 5. The increase of tensile strength in rats; 6. Biochemical demonstration of the RNA, DNA, albumin synthesis on human fibrocyte-cultures; 7.a, 7.b, Immunological studies; 8. Prostaglandin producing effect. The discovery of laser opened up new prospects in the field of the biological research and medical use.

  2. Laser Scanner For Automatic Storage

    Science.gov (United States)

    Carvalho, Fernando D.; Correia, Bento A.; Rebordao, Jose M.; Rodrigues, F. Carvalho

    1989-01-01

    The automated magazines are beeing used at industry more and more. One of the problems related with the automation of a Store House is the identification of the products envolved. Already used for stock management, the Bar Codes allows an easy way to identify one product. Applied to automated magazines, the bar codes allows a great variety of items in a small code. In order to be used by the national producers of automated magazines, a devoted laser scanner has been develloped. The Prototype uses an He-Ne laser whose beam scans a field angle of 75 degrees at 16 Hz. The scene reflectivity is transduced by a photodiode into an electrical signal, which is then binarized. This digital signal is the input of the decodifying program. The machine is able to see barcodes and to decode the information. A parallel interface allows the comunication with the central unit, which is responsible for the management of automated magazine.

  3. 激光对油松种子萌发、生长的 影响及作用机理%Study of laser function and influence on germination and growth of the Chinese pine seed

    Institute of Scientific and Technical Information of China (English)

    吴俊林; 袁胜利; 张宗权

    2001-01-01

    从植物生理学观点出发,用物理学方法讨论了He_Ne激光 对生物细胞膜的渗透性影响.结果表明,用He_Ne激光场辐照油松种子,有利于其细胞膜渗 透能力的提高,从而可产生有益的生物效应.%From the point of plant of physiology, by using phys ical methods, the paper presents a discussion the He_Ne laser affects the bio_me mbrane of permeability. The result shows that, if we use He_Ne laser field radia tes the Chinese pine seeds, it will be good for the improvement of cell membrane ′s permeability, and also it will have good effect on the biological effect.

  4. Backscattering measuring system for optimization of intravenous laser irradiation dose

    Science.gov (United States)

    Rusina, Tatyana V.; Popov, V. D.; Melnik, Ivan S.; Dets, Sergiy M.

    1996-11-01

    Intravenous laser blood irradiation as an effective method of biostimulation and physiotherapy becomes a more popular procedure. Optimal irradiation conditions for each patient are needed to be established individually. A fiber optics feedback system combined with conventional intravenous laser irradiation system was developed to control of irradiation process. The system consists of He-Ne laser, fiber optics probe and signal analyzer. Intravenous blood irradiation was performed in 7 healthy volunteers and 19 patients with different diseases. Measurements in vivo were related to in vitro blood irradiation which was performed in the same conditions with force-circulated venous blood. Comparison of temporal variations of backscattered light during all irradiation procedures has shown a strong discrepancy on optical properties of blood in patients with various health disorders since second procedure. The best cure effect was achieved when intensity of backscattered light was constant during at least five minutes. As a result, the optical irradiation does was considered to be equal 20 minutes' exposure of 3 mW He-Ne laser light at the end of fourth procedure.

  5. New Phase Fitted and Amplification Fitted Numerov-Type Methods for Periodic IVPs with Two Frequencies

    Directory of Open Access Journals (Sweden)

    Yonglei Fang

    2012-01-01

    Full Text Available Phase fitted and amplification fitted Numerov-type methods for periodic initial value problems with two frequencies are investigated. A one-frequency method and a two-frequency method are constructed. The two new methods both have algebraic order five and are dispersive of order six and dissipative of order five. The two-dimensional absolute stability region for the one-frequency method and the three-dimensional absolute stability region for the two-frequency method are plotted. Numerical experiments are reported to show the efficiency and competence of the two new methods.

  6. Histomorphologic and ultrastructural recovery of myopathy in rats treated with low-level laser therapy.

    Science.gov (United States)

    Servetto, Natalia; Cremonezzi, David; Simes, Juan Carlos; Di Pietro, Antonio; Campana, Vilma R

    2017-05-01

    The purpose of the present work was to study the effect of low-level laser therapy (LLLT): helium-neon (He-Ne) and gallium arsenide (Ga-As) laser on the histomorphology of muscle and mitochondria in experimental myopathy in rats. Thirty Suquía strain female rats were distributed in groups: (A) control (intact), (B) injured, (C) injured and treated with He-Ne laser, (D) injured and treated with Ga-As laser, (E) irradiated with He-Ne laser on the non-injured muscle, and (F) irradiated with Ga-As laser on the non-injured muscle. Myopathy was induced by injecting 0.05 mg/rat/day of adrenaline in the left gastrocnemius muscle at the same point on five consecutive days, in groups B, C, and D. LLLT was applied with 9.5 J cm(-2) daily for seven consecutive days in groups C, D, E, and F. The muscles were examined with optic and electronic microscopy. The inflammation was classified as absent, mild, and intense and the degree of mitochondrial alteration was graded I, II, III, and IV. Categorical data were statistically analyzed by Chi-square and the Fisher-Irwin Bilateral test, setting significant difference at p < 0.05. The damage found in muscle and mitochondria histomorphology in animals with induced myopathy (B) was intense or severe inflammation with grade III or IV of mitochondrial alteration. They underwent significant regression (p < 0.001) compared with the groups treated with He-Ne (C) and Ga-As (D) laser, in which mild or moderate inflammation was seen and mitochondrial alteration grades I and II, recovering normal myofibrillar architecture. No differences were found between the effects caused by the two lasers, or between groups A, E, and F. Group A was found to be different from B, C, and D (p < 0.001). LLLT in experimental myopathy caused significant muscular and mitochondrial morphologic recovery.

  7. Laser method of biological activity stimulation of cryoconserved hemopoietic tissue transplant

    Science.gov (United States)

    Khyznyak, Anatoly I.; Lesnik, Svetlana A.; Kogut, Georgy I.; Glukhenkaya, Galina T.

    1994-02-01

    The biological activity of cryoconserved fetal liver cells of mice (FLM) having undergone the He-Ne laser action has been estimated by the efficiency of their transplantation to mice- recipients exposed to lethal x-ray dose. The survival rate 30 days after x-ray exposure for those mice was 75% in comparison with 70% for mice with cryoconserved nonirradiated graft. The trial animals' peripheral blood investigations have been made. The obtained results indicate that the laser method of cryoconserved cells stimulation can help to increase the therapeutic efficiency of mielotransplantation.

  8. Laser polarimeter LP101M and its applications in liquid cromatography

    Science.gov (United States)

    Fajer, V.; Rodriguez, C.; Gonzalez, R.; Cossio, G.; Martinez, M.; Bravo, O.

    1996-02-01

    A high sensitivity laser polarimeter LP101M employing a He-Ne laser has been designed and constructed as a detector for liquid chromatography achieving a sensitivity better than 0.001 degree. The operation principle and technical characteristics of this instrument are described. A liquid gel chromatography column system suitable for sugar cane juice analysis was also designed and calibrated. It separated and analyzed the medium molecular weight carbohydrates and demonstrated the strong influence of these substances in the conventional polarimetric determinations.

  9. Pulsed inductive HF laser

    Energy Technology Data Exchange (ETDEWEB)

    Razhev, A M; Kargapol' tsev, E S [Institute of Laser Physics, Siberian Branch, Russian Academy of Sciences, Novosibirsk (Russian Federation); Churkin, D S; Demchuk, S V [Novosibirsk State University, Novosibirsk (Russian Federation)

    2016-03-31

    We report the results of experimentally investigated dependences of temporal, spectral and spatial characteristics of an inductive HF-laser generation on the pump conditions. Gas mixtures H{sub 2} – F{sub 2}(NF{sub 3} or SF6{sub 6}) and He(Ne) – H{sub 2} – F{sub 2}(NF{sub 3} or SF{sub 6}) were used as active media. The FWHM pulse duration reached 0.42 μs. This value corresponded to a pulsed power of 45 kW. For the first time, the emission spectrum of an inductive HF laser was investigated, which consisted of seven groups of bands with centres around the wavelengths of 2732, 2736, 2739, 2835, 2837, 2893 and 2913 nm. The cross section profile of the laser beam was a ring with a diameter of about 20 mm and width of about 5 mm. Parameters of laser operation in the repetitively pulsed regime were sufficiently stable. The amplitude instability of light pulses was no greater than 5% – 6%. (lasers)

  10. Characterization of CNRS Fizeau wedge laser tuner

    Science.gov (United States)

    A fringe detection and measurement system was constructed for use with the CNRS Fizeau wedge laser tuner, consisting of three circuit boards. The first board is a standard Reticon RC-100 B motherboard which is used to provide the timing, video processing, and housekeeping functions required by the Reticon RL-512 G photodiode array used in the system. The sampled and held video signal from the motherboard is processed by a second, custom fabricated circuit board which contains a high speed fringe detection and locating circuit. This board includes a dc level discriminator type fringe detector, a counter circuit to determine fringe center, a pulsed laser triggering circuit, and a control circuit to operate the shutter for the He-Ne reference laser beam. The fringe center information is supplied to the third board, a commercial single board computer, which governs the data collection process and interprets the results.

  11. Thermo-optic properties of laser crystals in the 100-300 K temperature range: Y3Al5O12 (YAG), YAlO3 (YALO) and LiYF4 (YLF)

    Science.gov (United States)

    Aggarwal, R. L.; Ripin, D. J.; Ochoa, J. R.; Fan, T. Y.

    2005-04-01

    Spectroscopic and thermo-optic properties of laser crystals are needed for solid-state laser performance modeling. Here we present a brief report on the measurement of key thermo-optic properties: thermal conductivity (κ), coefficient of thermal expansion (α), and thermal coefficient of refractive index (dn/dT). κ was measured using laser-flash method. α was measured using a 632.8-nm He-Ne Michelson laser interferometer. dn/dT was determined at 1064 nm, using measured values of α and the thermal coefficient of the optical path length. An extended paper containing more detailed results will be submitted to the Journal of Applied Physics.

  12. Laser influence to biosystems

    Directory of Open Access Journals (Sweden)

    Jevtić Sanja D.

    2015-01-01

    Full Text Available In this paper a continous (cw lasers in visible region were applied in order to study the influence of quantum generator to certain plants. The aim of such projects is to analyse biostimulation processes of living organizms which are linked to defined laser power density thresholds (exposition doses. The results of irradiation of corn and wheat seeds using He-Ne laser in the cw regime of 632.8nm, 50mW are presented and compared to results for other laser types. The dry and wet plant seeds were irradiated in defined time intervals and the germination period plant was monitored by days. Morphological data (stalk thickness, height, cob lenght for chosen plants were monitored. From the recorded data, for the whole vegetative period, we performed appropriate statistical data processing. One part of experiments were the measurements of coefficient of reflection in visible range. Correlation estimations were calculated and discussed for our results. Main conclusion was that there were a significant increments in plant's height and also a cob lenght elongation for corn.

  13. Laser effects on osteogenesis

    Science.gov (United States)

    Freitas, I. G. F.; Baranauskas, V.; Cruz-Höfling, M. A.

    2000-02-01

    The traumatic or surgical cutting of a long bone is immediately followed by a sequence of repair processes in which the osteogenic cells of the periosteum start to proliferate and differentiate in osteoblast cells. In this work, we explored the influence of a He-Ne laser on osteogenesis after a controlled surgical fracture. We used young male adult Wistar rats (of mass between 250 and 300 g). The fracture was provoked by piercing a 2-mm-diameter hole in just one cortical tibia surface. Laser treatment was started 24 h after the surgery. The animals were separated into three groups, for different radiation doses, and after daily applications, they were sacrificed at 8 or 15 days. Light and electron microscopies revealed that the laser treatment of the lesion with doses of 31.5 and 94.7 J cm -2 resulted in the formation of thicker bony trabeculae, which indicates a greater synthesis of collagen fibers and therefore that the osteoblastic activity was increased by the low-energy laser radiation.

  14. Color Laser Microscope

    Science.gov (United States)

    Awamura, D.; Ode, T.; Yonezawa, M.

    1987-04-01

    A color laser microscope utilizing a new color laser imaging system has been developed for the visual inspection of semiconductors. The light source, produced by three lasers (Red; He-Ne, Green; Ar, Blue; He-Cd), is deflected horizontally by an AOD (Acoustic Optical Deflector) and vertically by a vibration mirror. The laser beam is focused in a small spot which is scanned over the sample at high speed. The light reflected back from the sample is reformed to contain linear information by returning to the original vibration mirror. The linear light is guided to the CCD image sensor where it is converted into a video signal. Individual CCD image sensors are used for each of the three R, G, or B color image signals. The confocal optical system with its laser light source yields a color TV monitor image with no flaring and a much sharper resolution than that of the conventional optical microscope. The AOD makes possible a high speed laser scan and a NTSC or PAL TV video signal is produced in real time without any video memory. Since the light source is composed of R, G, and B laser beams, color separation superior to that of white light illumination is achieved. Because of the photometric linearity of the image detector, the R, G, and B outputs of the system are most suitably used for hue analysis. The CCD linear image sensors in the optical system produce no geometrical distortion, and good color registration is available principally. The output signal can be used for high accuracy line width measuring. The many features of the color laser microscope make it ideally suited for the visual inspection of semiconductor processing. A number of these systems have already been installed in such a capacity. The Color Laser Microscope can also be a very useful tool for the fields of material engineering and biotechnology.

  15. Using laser to measure stem thickness and cut weed stems

    DEFF Research Database (Denmark)

    Heisel, T.; Schou, Jørgen; Andreasen, C.

    2002-01-01

    Stem thickness of the weed Solanum nigrum and the crop sugarbeet was determined with a He-Ne laser using a novel non-destructive technique measuring stem shadow. Thereafter, the stems were cut close to the soil surface with a CO2 laser. Treatments were carried out on pot plants, grown...... in the greenhouse, at two different growth stages, and plant dry matter was measured 2-5 weeks after treatment. The relationship between plant dry weight and laser energy was analysed using two different non-linear dose-response regression models; one model included stem thickness as a variable, the other did not....... A binary model was also tested. The non-linear model incorporating stem thickness described the data best, indicating that it would be possible to optimize laser cutting by measuring stem thickness before cutting. The general tendency was that more energy was needed the thicker the stem. Energy uses...

  16. A numerical simulation of photothermal response in laser medicine

    Institute of Scientific and Technical Information of China (English)

    Xiaoxia Li(李小霞); Shifu Fan(范世福); Youquan Zhao(赵友全); Songshan Xiao(肖松山)

    2004-01-01

    In this paper, we reported a numerical solution of laser induced thermal effect in the bio-tissue. The model of photothermal effect and classical Pennes bio-heat transfer equation were introduced. Finite element method (FEM), which was realized by Matlab software, was used to calculate the temperature distribution. He-Ne laser (633 nm) was used to simulate the physical therapy in in vivo skin tissue. Under the cylinder coordinates, the three-dimension(3-D) geometry of tissue was reduced to two-dimension(2-D)computation. The results contained the radial, axial and temperature 3-D color plot. Combining the time animation display was possible. By changing the laser and tissue parameters we can get different results.This will be the initial and indispensable work of the non-destructive evaluation of the laser induced injury.

  17. The effects of two different low level laser therapies in the treatment of patients with chronic low back pain: A double-blinded randomized clinical trial.

    Science.gov (United States)

    Koldaş Doğan, Şebnem; Ay, Saime; Evcik, Deniz

    2017-01-01

    The purpose of this study was to compare the effectiveness of two different laser therapy regimens on pain, lumbar range of motions (ROM) and functional capacity in patients with chronic low back pain (CLBP). Forty nine patients with CLBP were randomly assigned into two groups. Group 1 (n= 20) received hot-pack + laser therapy 1 (wavelength of 850 nm Gallium-Aluminum-Arsenide (Ga-Al-As) laser); group 2 (n= 29) received hot-pack + laser therapy 2 (wavelength of 650 nm Helyum-Neon (He-Ne), 785 ve 980 nm Gal-Al-As combined plaque laser) for 15 sessions. Pain severity, patient's and physician's global assessments were evaluated with visual analogue scale (VAS). Modified Schober test, right and left lateral flexion measurements were done. Modified Oswestry Disability Questionnaire (MODQ) was used for evaluation of functional disability. Measurements were done before and after the treatment. After treatment there were statistically significant improvements in pain severity, patient's and physician's global assessment, ROM and MODQ scores in both groups (Ptreatment there were statistically significant differences between the groups in lateral flexion measurements and MODQ scores (P 0.05) in favor of those patients who received combined plaque laser therapy (group 2). Laser therapy applied with combined He-Ne and Ga-Al-As provides more improvements in lateral flexion measurements and disability of the patients, however no superiority of the two different laser devices to one another were detected on pain severity.

  18. 3c/4e [small sigma, Greek, circumflex]-type long-bonding competes with ω-bonding in noble-gas hydrides HNgY (Ng = He, Ne, Ar, Kr, Xe, Rn; Y = F, Cl, Br, I): a NBO/NRT perspective.

    Science.gov (United States)

    Zhang, Guiqiu; Li, Hong; Weinhold, Frank; Chen, Dezhan

    2016-03-21

    Noble-gas hydrides HNgY are frequently described as a single ionic form (H-Ng)(+)Y(-). We apply natural bond orbital (NBO) and natural resonance theory (NRT) analyses to a series of noble-gas hydrides HNgY (Ng = He, Ne, Ar, Kr, Xe, Rn; Y = F, Cl, Br, I) to gain quantitative insight into the resonance bonding of these hypervalent molecules. We find that each of the studied species should be better represented as a resonance hybrid of three leading resonance structures, namely, H-Ng(+ -):Y (I), H:(- +)Ng-Y (II), and H^Y (III), in which the "ω-bonded" structures I and II arise from the complementary donor-acceptor interactions nY → σ*HNg and nH → σ*NgY, while the "long-bond" ([small sigma, Greek, circumflex]-type) structure III arises from the nNg → [small sigma, Greek, circumflex]*HY/[small sigma, Greek, circumflex]HY interaction. The bonding for all of the studied molecules can be well described in terms of the continuously variable resonance weightings of 3c/4e ω-bonding and [small sigma, Greek, circumflex]-type long-bonding motifs. Furthermore, we find that the calculated bond orders satisfy a generalized form of "conservation of bond order" that incorporates both ω-bonding and long-bonding contributions [viz., (bHNg + bNgY) + bHY = bω-bonding + blong-bonding = 1]. Such "conservation" throughout the title series implies a competitive relationship between ω-bonding and [small sigma, Greek, circumflex]-type long-bonding, whose variations are found to depend in a chemically reasonable manner on the electronegativity of Y and the outer valence-shell character of the central Ng atom. The calculated bond orders are also found to exhibit chemically reasonable correlations with bond lengths, vibrational frequencies, and bond dissociation energies, in accord with Badger's rule and related empirical relationships. Overall, the results provide electronic principles and chemical insight that may prove useful in the rational design of noble-gas hydrides of

  19. Response of antioxidant defense system to laser radiation apical meristem of Isatis indigotica seedlings exposed to UV-B

    Science.gov (United States)

    2009-01-01

    To determine the response of antioxidant defense system to laser radiation apical meristem of Isatis indigotica seedlings, Isatis indigotica seedlings were subjected to UV-B radiation (10.08 kJ m−2) for 8 h day−1 for 8 days (PAR, 220 µmol m−2 s−1) and then exposed to He-Ne laser radiation (633 nm; 5.23 mW mm−2; beam diameter: 1.5 mm) for 5 min each day without ambient light radiation. Changes in free radical elimination systems were measured, the results indicate that: (1) UV-B radiation enhanced the concentration of Malondialdahyde (MDA) and decreased the activities of superoxide dismutase (SOD), catalase (CAT) and peroxidase (POD) in seedlings compared with the control. The concentration of MDA was decreased and the activities of SOD, CAT and POD were increased when seedlings were subjected to elevated UV-B damage followed by laser; (2) the concentration of UV absorbing compounds and proline were increased progressively with UV-B irradiation, laser irradiation and He-Ne laser irradiation plus UV-B irradiation compared with the control. These results suggest that laser radiation has an active function in repairing UV-B-induced lesions in seedlings. PMID:19820308

  20. Low-power laser irradiation of blood inhibits platelet function: role of cyclic GMP

    Science.gov (United States)

    Brill, Alexander G.; Brill, Gregory E.; Shenkman, Boris; Tamarin, Ilya; Dardik, Rima; Varon, David; Savion, Naphtali

    1998-12-01

    The aim of the present work was to investigate effect of low power laser irradiation (LPLI) on platelet function in vitro. He-Ne laser (Optronix, USA; (lambda) - 632.8 nm, output power - 7 mW) was employed. Platelet adhesion and aggregation in whole blood (WB) under defined shear conditions were assayed by a Cone and Plate(let) Analyzer. Platelet activation was evaluated by flow cytometry. Level of platelet cGMP was estimated by immunoenzyme assay. Experiments performed showed that LPLI of WB resulted in decrease of platelet deposition on extracellular matrix at high shear rate (1300 s-1). Similar results were obtained using surfaces precoated with either collagen type I or von Willebrand factor. LPLI inhibited fibrinogen binding as well as P-selectin expression on the platelet membrane, induced by thrombin analogue. It was found out that primary acceptor of laser energy responsible for the effect on platelets was located in platelets themselves and not in blood plasma or in other blood cells. LPLI of gel- filtered platelets resulted in increase of intracellular level of cGMP both in the absence and in presence of izobutylmethylxantine (phosphodiesterase inhibitor) suggesting stimulation of synthesis rather than destruction of cGMP under the influence of LPLI. It is suggested that guanylate cyclase and/or NO-synthase might serve as primary acceptors of He-Ne laser light in platelets.

  1. Interferometric length metrology for the dimensional control of ultra-stable Ring Laser Gyroscopes

    CERN Document Server

    Belfi, J; Cuccato, D; Di Virgilio, A; Maccioni, E; Ortolan, A; Santagata, R

    2014-01-01

    We present the experimental test of a method for controlling the absolute length of the diagonals of square ring laser gyroscopes. The purpose is to actively stabilize the ring cavity geometry and to enhance the rotation sensor stability in order to reach the requirements for the detection of the relativistic Lense-Thirring effect with a ground-based array of optical gyroscopes. The test apparatus consists of two optical cavities 1.32 m in length, reproducing the features of the ring cavity diagonal resonators of large frame He-Ne ring laser gyroscopes. The proposed measurement technique is based on the use of a single diode laser, injection locked to a frequency stabilized He-Ne/Iodine frequency standard, and a single electro-optic modulator. The laser is modulated with a combination of three frequencies allowing to lock the two cavities to the same resonance frequency and, at the same time, to determine the cavity Free Spectral Range (FSR). We obtain a stable lock of the two cavities to the same optical fre...

  2. Electric current heating calibration of a laser holographic nondestructive test system

    Science.gov (United States)

    Liu, H.-K.; Kurtz, R. L.

    1975-01-01

    Holographic NDT was used to measure small surface displacements controlled by electric heating by detecting the difference of the interference fringe patterns as viewed through the hologram on a real time basis. A perforated aluminum test plate, with the holes used to position thin metal foils, was used in the experiment. One of the foils was connected to an electric power source and small displacements of the foil were caused and controlled by Ohmic heating. An He-Ne laser was used to perform the holography.

  3. Surgical Lasers In Gynecology

    Science.gov (United States)

    Schellhas, Helmut F.; Barnes, Alfonso E.

    1982-12-01

    Multipurpose surgical CO2 lasers marketed in the USA have been developed to be applicable to a variety of surgical procedures in many surgical fields. They are all suited for endoscopic surgical procedures and can be fitted to all standard surgical microscopes. They all can adjust the focal length of the laser beam to the different standard focal lengths of the surgical microscope which for instance in laryngoscopy is 400 mm and in colposcopy 300 mm. One laser instrument can even change the spot size in a given focal distance which is very advantageous for some microsurgical procedures (Merrimack Laboratories 820). All multipurpose surgical CO2 laser systems provide a multi-articulated surgical arm for free-hand surgery. The surgical arms are cumbersome to use but they are adapted to the surgeons needs with ingenuity. The practicality of the multi-articulated surgical arms depends mostly on the distance of the handpiece from the surgical console which now is also overbridged by the laser tube in most surgical laser system. The spot size of the beam is variable in most handpieces by interchangeable lenses which modify the focal distance of the beam and the power density. Another common feature in all systems is a coaxial He-Ne pilot light which provides a red spot which unfortunately becomes invisible in a bleeding surgical field. Most surgical laser systems have a spacial mode of TEM 00 which is essential for incisional surgery. The continuous mode of beam delivery is used for incisional surgery and also for most endoscopic procedures.

  4. Benefits of low-power lasers on oral soft tissue

    Science.gov (United States)

    Eduardo, Carlos d. P.; Cecchini, Silvia C. M.; Cecchini, Renata C.

    1996-04-01

    The last five years have represented a great advance in relation to laser development. Countries like Japan, United States, French, England, Israel and others, have been working on the association of researches and clinical applications, in the field of laser. Low power lasers like He-Ne laser, emitting at 632,8 nm and Ga-As-Al laser, at 790 nm, have been detached acting not only as a coadjutant but some times as an specific treatment. Low power lasers provide non thermal effect at wavelengths believed to stimulate circulation and cellular activity. These lasers have been used to promote wound healing and reduce inflammation edema and pain. This work presents a five year clinical study with good results related to oral tissue healing. Oral cavity lesions, like herpes and aphthous ulcers were irradiated with Ga-Al- As laser. In both cases, an excellent result was obtained. The low power laser application decrease the painful sintomatology immediately and increase the reparation process of these lesions. An excellent result was obtained with application of low power laser in herpetic lesions associated with a secondary infection situated at the lip commissure covering the internal tissue of the mouth. The healing occurred after one week. An association of Ga-Al-As laser and Nd:YAG laser have been also proven to be good therapy for these kind of lesions. This association of low and high power laser has been done since 1992 and it seems to be a complement of the conventional therapies.

  5. Curative Effect of Diode Laser and He-Ne Laser in Treating TMJDS by Irradiating Acupunture Points%半导体激光和氦-氖激光穴位照射治疗颞颌关节紊乱症的疗效

    Institute of Scientific and Technical Information of China (English)

    张洁; 孙红英

    2001-01-01

    @@颞颌关节功能紊乱综合征(TMJDS)是口腔颌面部的常见疾病,发病率约为20%左右。主要临床表现是开口及咀嚼时关节疼痛,张闭口时关节弹响,张口受限。X线摄片检查,关节面及骨质结构均无异常,只能发现关节活动受限或活动度过大。TMJDS的发病因素十分复杂,以往曾采用各种理疗、关节腔内注射类固醇,也有采用手术方法切除关节盘或高位切除髁状突来治疗。我们根据弱激光具有消炎、镇痛和调节机体免疫功能的机制,采用低功率半导体激光和He-Ne激光照射颌面部相关穴位,疗效较满意。

  6. Two frequency ICRF heating of D-T plasmas on TFTR

    Energy Technology Data Exchange (ETDEWEB)

    Rogers, J.H.; Majeski, R.; Wilson, J.R.; Hosea, J.C.; Schilling, G.; Stevens, J. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Ho, Y.L. [Science Applications International Corp., San Diego, CA (United States); Raman, S. [Michigan Univ., Ann Arbor, MI (United States); Rasmussen, D.A. [Oak Ridge National Lab., TN (United States)

    1993-11-01

    Modifications have been made to allow two of the ICRF antennas (bays L and M) on TFTR to operate at either of two frequencies, 43 MHz or 64 MHz. This was accomplished by lengthening the resonant loops feeding the antennas (2{lambda} at 43 MHz, 3{lambda} at 64 MHz) and replacing the conventional quarter wave impedance transformers with a tapered impedance design. The other two antennas (bays K and N) will operate at a fixed frequency, 43 MHz. The two frequency operation allows a combination of {sup 3}He-minority (or T second harmonic) and H-minority heating at full toroidal field on TFIR. Multiple frequency operation may also be useful in direct electron heating and current drive experiments. Other modifications have been made which are expected to permit arbitrary phasing between the current straps on bays M and L. The system design of the antenna, resonant loops and impedance matching system as well as preliminary TFTR results are discussed.

  7. Laser speckle tracking for monitoring and analysis of retinal photocoagulation

    Science.gov (United States)

    Seifert, Eric; Bliedtner, Katharina; Brinkmann, Ralf

    2014-02-01

    Laser coagulation of the retina is an established treatment for several retinal diseases. The absorbed laser energy and thus the induced thermal damage varies with the transmittance and scattering properties of the anterior eye media and with the pigmentation of the fundus. The temperature plays the most important role in the coagulation process. An established approach to measure a mean retinal temperature rise is optoacoustics, however it provides limited information on the coagulation. Phase sensitive OCT potentially offers a three dimensional temporally resolved temperature distribution but is very sensitive to slightest movements which are clinically hard to avoid. We develop an optical technique able to monitor and quantify thermally and coagulation induced tissue movements (expansions and contractions) and changes in the tissue structure by dynamic laser speckle analysis (LSA) offering a 2D map of the affected area. A frequency doubled Nd:YAG laser (532nm) is used for photocoagulation. Enucleated porcine eyes are used as targets. The spot is 100μm. A Helium Neon laser (HeNe) is used for illumination. The backscattered light of a HeNe is captured with a camera and the speckle pattern is analyzed. A Q-switched Nd:YLF laser is used for simultaneous temperature measurements with the optoacoustic approach. Radial tissue movements in the micrometer regime have been observed. The signals evaluation by optical flow algorithms and generalized differences tuned out to be able to distinguish between regions with and without immediate cell damage. Both approaches have shown a sensitivity of 93% and a specificity above 99% at their optimal threshold.

  8. Propagation and stability characteristics of a 500-m-long laser-based fiducial line for high-precision alignment of long-distance linear accelerators.

    Science.gov (United States)

    Suwada, Tsuyoshi; Satoh, Masanori; Telada, Souichi; Minoshima, Kaoru

    2013-09-01

    A laser-based alignment system with a He-Ne laser has been newly developed in order to precisely align accelerator units at the KEKB injector linac. The laser beam was first implemented as a 500-m-long fiducial straight line for alignment measurements. We experimentally investigated the propagation and stability characteristics of the laser beam passing through laser pipes in vacuum. The pointing stability at the last fiducial point was successfully obtained with the transverse displacements of ±40 μm level in one standard deviation by applying a feedback control. This pointing stability corresponds to an angle of ±0.08 μrad. This report contains a detailed description of the experimental investigation for the propagation and stability characteristics of the laser beam in the laser-based alignment system for long-distance linear accelerators.

  9. Intermode beat stabilized laser with frequency pulling.

    Science.gov (United States)

    Yokoyama, S; Araki, T; Suzuki, N

    1994-01-20

    A frequency-stabilized two-mode He-Ne laser has been developed. The intermode beat frequency of the experimental laser was approximately 600 MHz for a 25-cm cavity. The laser frequency in which the mode stands is pulled to the center of the gain curve (frequency pulling). The degree of pulling depends on where the longitudinal modes stand in the broadened gain curve. Beat frequency is thereby changed periodically of the order of hundreds of kilohertz with respect to cavity expansion. The frequency pulling was effectively used for frequency stabilization of the laser. The standing position of the longitudinal mode lights was locked in the gain curve by controlling the change of intermode beat frequency. A microwave mixer was applied to extract the frequency change of the intermode beat. Excellent frequency stability (10(10) for the laser oscillation and 10(6) for the beat frequency) was attained. The polarization orthogonality of the proposed laser was superior to that of Zeeman lasers.

  10. Efficacy of fractional lasers in treating alopecia: a literature review.

    Science.gov (United States)

    Perper, Marina; Aldahan, Adam S; Fayne, Rachel A; Emerson, Christopher P; Nouri, Keyvan

    2017-08-16

    Hair loss stemming from different types of alopecia, such as androgenic alopecia and alopecia areata, negatively affects over half the population and, in many circumstances, causes serious psychosocial distress. Current treatment options for alopecia, such as minoxidil, anthralin, and intralesional corticosteroids, vary efficacy and side effect profiles. It is known that low-level laser/light therapies (LLLT), or photobiomodulations, such as the US FDA-cleared HairMax Lasercomb®, He-Ne laser, and excimer laser, are relatively affordable, user-friendly, safe, and effective forms of treatment for hair loss. While less is known about the effectiveness of fractional lasers for combating hair loss, research suggests that by creating microscopic thermal injury zones, fractional lasers may cause an increase in hair growth from a wound healing process, making them potential therapeutic options for alopecia. A literature review was performed to evaluate the effectiveness of fractional lasers on hair regrowth. The specific fractional laser therapies include the 1550-nm nonablative fractional erbium-glass laser, the ablative fractional 2940-nm erbium:YAG laser, and the ablative fractional CO2 fractional laser. Additional randomized controlled trials are necessary to further evaluate the effectiveness of the lasers, as well as to establish appropriate parameters and treatment intervals.

  11. Suppression of cyclotron instability in Electron Cyclotron Resonance ion sources by two-frequency heating

    Energy Technology Data Exchange (ETDEWEB)

    Skalyga, V. [Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanova st., Nizhny Novgorod (Russian Federation); Lobachevsky State University of Nizhny Novgorod (UNN), 23 Gagarina st., Nizhny Novgorod (Russian Federation); Izotov, I.; Mansfeld, D. [Institute of Applied Physics of Russian Academy of Sciences, 46 Ulyanova st., Nizhny Novgorod (Russian Federation); Kalvas, T.; Koivisto, H.; Komppula, J.; Kronholm, R.; Laulainen, J.; Tarvainen, O. [Department of Physics, University of Jyväskylä, Jyväskylä (Finland)

    2015-08-15

    Multiple frequency heating is one of the most effective techniques to improve the performance of Electron Cyclotron Resonance (ECR) ion sources. The method increases the beam current and average charge state of the extracted ions and enhances the temporal stability of the ion beams. It is demonstrated in this paper that the stabilizing effect of two-frequency heating is connected with the suppression of electron cyclotron instability. Experimental data show that the interaction between the secondary microwave radiation and the hot electron component of ECR ion source plasmas plays a crucial role in mitigation of the instabilities.

  12. High fluence laser irradiation induces reactive oxygen species generation in human lung adenocarcinoma cells

    Science.gov (United States)

    Wang, Fang; Xing, Da; Chen, Tong-Sheng

    2006-09-01

    Low-power laser irradiation (LPLI) has been used for therapies such as curing spinal cord injury, healing wound et al. Yet, the mechanism of LPLI remains unclear. Our previous study showed that low fluences laser irradiation induces human lung adenocarcinoma cells (ASTC-a-1) proliferation, but high fluences induced apoptosis and caspase-3 activation. In order to study the mechanism of apoptosis induced by high fluences LPLI further, we have measured the dynamics of generation of reactive oxygen species (ROS) using H IIDCFDA fluorescence probes during this process. ASTC-a-1 cells apoptosis was induced by He-Ne laser irradiation at high fluence of 120J/cm2. A confocal laser scanning microscope was used to perform fluorescence imaging. The results demonstrated that high fluence LPLI induced the increase of mitochondria ROS. Our studies contribute to clarify the biological mechanism of high fluence LPLI-induced cell apoptosis.

  13. Pulsed-laser-induced damage in semiconductors Ge, ZnS, and ZnSe at 10.6um

    Science.gov (United States)

    Lefranc, Sebastian; Kudriavtsev, Eugene M.; Autric, Michel L.

    1998-04-01

    Laser irradiation induced damage to several materials of interest for use as 10.6 micrometers laser system windows is investigated in this paper. The irradiation source in these single shot experiments was a pulsed TEA CO2 laser. Damage initiation in semiconductors has been studied during the interaction by measuring the variation of the transmitted intensity of a He- Ne and a CO2 cw lasers through the samples. Results show that damages appear at the beginning of the laser-matter interaction process on both surfaces and in the bulk of the materials. The damaged materials have been characterized for various incident fluences by means of optical microscopy and scanning electron microscopy in terms of topography and morphology. The modified surface chemical analysis and the structural analysis have been carried out using energy dispersive x-ray and Raman spectroscopy.

  14. Strong optical feedback in birefringent dual frequency laser

    Institute of Scientific and Technical Information of China (English)

    Mao Wei; Zhang Shu-Lian

    2006-01-01

    Strong optical feedback in a birefringent dual frequency He-Ne laser with a high reflectivity feedback mirror has been investigated for the first time. The output characteristics of two orthogonally polarized modes are demonstrated in two different optical feedback cases: one is for both modes being fed back and the other is for only one of the modes being fed back. Strong mode competition can be observed between the two modes with strong optical feedback. And when one mode's intensity is near its maximum, the other mode is nearly extinguished. When both modes are fed back into the laser cavity, the mode competition is stronger than when only one mode is fed back. The difference in initial intensity between the two orthogonally polarized modes plays an important role in the mode competition, which has been experimentally and theoretically demonstrated.

  15. Scanning laser system to determine the corneal shape

    Science.gov (United States)

    Ascanio, Gabriel; Caballero-Ruiz, Alberto; Ruiz-Huerta, Leopoldo; Gonzalez-Cardel, Mario; Diaz-Uribe, Rufino

    2005-07-01

    The development and tests of a scanning system to be used to determine the corneal topography with the laser deflectometry method are presented. In this equipment, a He-Ne laser beam scans the cornea by describing a spiral trajectory generated by two components: radial and angular. The first component is produced by the displacement of a plane mirror moved by a linear pneumatic actuator. The second component is produced by passing the beam through a Dove prism which is rotating by means of a belt drive coupled to a high-speed electric motor. Tests were first performed by analyzing both components independently and then they were characterized by combining the two components. Results are discussed and compared to those of an earlier cited work.

  16. Microwave signal processing in two-frequency domain for ROF systems implementation: training course

    Science.gov (United States)

    Morozov, Oleg G.; Morozov, Gennady A.

    2014-04-01

    This article is presented materials from two tutorials: "Optical two-frequency domain reflectometry1, 2" and "Microwave technologies in industry, living systems and telecommunications3". These materials were prepared for master training courses and listed in the "SPIE Optical Education Directory" for 2013/2014. The main its theme is microwave photonics. Microwave photonics has been defined as the study of photonic devices operating at microwave frequencies and their application to microwave and optical systems. Its initial rationale was to use the advantages of photonic technologies to provide functions in microwave systems that are very complex or even impossible to carry out directly in the radiofrequency domain. But microwave photonics is also succeeding in incorporating a variety of techniques used in microwave engineering to improve the performance of photonic communication networks and systems. Three parts of this chapter are devoted to applications and construction principles of systems forming microwave photonic filters, measuring instantaneous frequency of microwave heterodyne signals and characterizing stimulated Mandelstam- Brillouin scattering spectrum in ROF systems. The main emphasis is on the use of the two-frequency symmetric radiation, generated by the Il'in-Morozov's method4, in given systems. It is forming radiation for the synthesis of optical filters coefficients, it's application and processing determine the increase in the signal-to-noise ratio during heterodyne frequencies monitoring and characterization of nonlinear effects spectrum.

  17. Therapeutic effect of the NMDA antagonist MK-801 on low-level laser induced retinal injury

    Science.gov (United States)

    Yan, W.-H.; Wu, J.; Chen, P.; Dou, J.-T.; Pan, C.-Y.; Mu, Y.-M.; Lu, J.-M.

    2009-03-01

    The aim of this article was to explore the mechanism of injury in rat retina after constant low-level helium-neon (He-Ne) laser exposure and therapeutic effects of MK-801, an N-methyl-D-aspartate (NMDA) receptor antagonist, on laser-induced retinal injury. He-Ne laser lesions were created in the central retina of adult Wistar Kyoto rats and were followed immediately by intraperitoneal injection of MK-801 (2 mg/kg) or saline, macroscopical and microscopical lesion were observed by funduscope and light microscope. Ultrastructural changes of the degenerating cells were examined by electron microscopy. Photoreceptor apoptosis was evaluated by TdT-mediated dUTP nick end-labeling (TUNEL). mRNA levels were measured by in situ hybridization and NMDA receptor expression was determined by immunohistochemistry. Laser induced damage was histologically quantified by image-analysis morphometry. Electroretinograms (ERGs) were recorded at different time point after the cessation of exposure to constant irradiation. There was no visible bleeding, exudation or necrosis under funduscope. TUNEL and electron microscopy showed photoreceptor apoptosis after irradiation. MK-801-treated animals had significantly fewer TUNEL-positive cells in the photoreceptors than saline-treated animals after exposure to laser. In situ hybridization (ISH) showed that the NMDAR mRNA level of MK-801-treated rats decreased in the inner plexiform layer 6 h after the cessation of exposure to constant irradiation when compared with that of saline-treated rats. So did Immunohistochemistry (IHC). Electroretinogram showed that b-wave amplitudes of MK-801-treated group were higher than that of saline-treated group after laser exposure. These findings suggest that Low level laser may cause the retinal pathological changes under given conditions. High expression of NMDAR is one of the possible mechanisms causing experimental retinal laser injury of rats. MK-801 exhibits the therapeutic effect due to promote the

  18. Effect of helium-neon laser irradiation on hair follicle growth cycle of Swiss albino mice.

    Science.gov (United States)

    Shukla, S; Sahu, K; Verma, Y; Rao, K D; Dube, A; Gupta, P K

    2010-01-01

    We report the results of a study carried out to investigate the effect of helium-neon (He-Ne) laser (632.8 nm) irradiation on the hair follicle growth cycle of testosterone-treated and untreated mice. Both histology and optical coherence tomography (OCT) were used for the measurement of hair follicle length and the relative percentage of hair follicles in different growth phases. A positive correlation (R = 0.96) was observed for the lengths of hair follicles measured by both methods. Further, the ratios of the lengths of hair follicles in the anagen and catagen phases obtained by both methods were nearly the same. However, the length of the hair follicles measured by both methods differed by a factor of 1.6, with histology showing smaller lengths. He-Ne laser irradiation (at approximately 1 J/cm(2)) of the skin of both the control and the testosterone-treated mice was observed to lead to a significant increase (p < 0.05) in % anagen, indicating stimulation of hair growth. The study also demonstrates that OCT can be used to monitor the hair follicle growth cycle, and thus hair follicle disorders or treatment efficacy during alopecia.

  19. Scattering and Absorbing Characteristics of He-Ne Laser in Rabbit Arteries and Veins in Kubelka-Munk Model in Vitro%Kubelka-Munk模型下的兔血管对氦-氖激光的散射与吸收特性

    Institute of Scientific and Technical Information of China (English)

    魏华江; 李晓原; 刘小星; 许静芬; 谭润初

    2001-01-01

    测量了兔动脉和静脉对He-Ne激光的反射和透射传输特性.实验采用两积分球系统及波长为632.8 nm的He-Ne激光器,并根据测量数据及采用Kubelka-Munk模型分析和计算了兔动脉和静脉组织对该波长激光的吸收系数、散射系数及总的光强I(x)及前向散射通量i(x)和后向散射通量j(x)随厚度的变化情况.结果表明,兔动脉和静脉的漫反射率和透射率有明显差别,而且,动脉对激光的吸收系数明显较静脉的要小,而动脉对激光的散射系数却明显较静脉的要大,在动脉和静脉组织中总的光强I(x)及前向散射通量i(x)和后向散射通量j(x)随组织厚度的变化情况也有明显的区别.

  20. Psychological Nursing on He-Ne Laser in the Treatment of Pediatric Acute Otitis Media on the Compliance Wit%心理护理对He-Ne激光治疗小儿急性中耳炎依从性的影响

    Institute of Scientific and Technical Information of China (English)

    苏炳凤

    2013-01-01

    目的 探讨心理护理对应用氦氖激光治疗小儿急性中耳炎依从性的影响.方法 对2010年1月-2012年1月共收治90例(3~7)岁的小儿急性中耳炎患儿,氦氖激光治疗中,对患儿采取舒适的体位,除了按严格的操作规程进行常规治疗外,对家长实施相关知识的指导及做好患儿及家长的心理护理.结果 患儿及家长的依从性较好,减少了患儿的用药量,缩短了治疗时间,取得满意疗效.结论 氦氖激光治疗小儿急性中耳炎,应做好患儿及家长心理护理,更好提高治疗的依从性.

  1. The Study the Recovery Effect of Physiological Function after Ischiadic Nerve Injury on Rats by He-Ne Laser Irradiation%He-Ne激光照射对大鼠坐骨神经损伤后修复作用的研究

    Institute of Scientific and Technical Information of China (English)

    郭克民; 张建民; 李云涛; 郜超军

    2004-01-01

    目的研究He-Ne激光照射对大鼠神经损伤生理功能恢复的影响.方法采用He-Ne激光照射大鼠损伤的坐骨神经,观察He-Ne激光照射后神经电生理功能变化及神经纤维的再生情况.结果激光照射可促进神经纤维的再生过程,He-Ne激光照射组的神经轴索数明显高于对照组(P<0.01).结论He-Ne激光照射大鼠损伤的坐骨神经有促进功能恢复的作用.

  2. Effects of intravascular low-level He-Ne laser irradiation therapy on vascular endothelial function in patients with ischemic stroke%低强度氦-氖激光血管内照射对缺血性脑卒中患者血管内皮功能的影响

    Institute of Scientific and Technical Information of China (English)

    程旭青; 李涵志; 邹文; 朱爱华; 林柏文

    2002-01-01

    目的探讨低强度氦-氖激光血管内照射疗法(ILLI)对缺 血性脑卒中患者血管内皮功能的影响. 方法将48例缺血性脑卒中 患者随机分为常规组和ILLI治疗组,ILLI治疗组在常规治疗组的基础上加用ILLI疗法.两组 病人均于入院的次日及第29天应用高分辨率超声检测肱动脉流量介导的舒张活性(FMD)变化 . 结果经四周的治疗后,两组的FMD值均较各自治疗前显著升高 ,但ILLI组的FMD升高较常规组更为显著. 结论低强度氦-氖激 光血管内照射疗法能有效改善缺血性脑卒中患者的血管内皮功能.

  3. 低能量He-Ne激光血管内照射合血府逐淤胶囊治疗缺血性脑血管病后抑郁状态的疗效研究%Clinical study of low intensity He-Ne laser intravascular irradiation combined with Xuefuzhuyu granule therapy on depressive state caused by ischemic cerebrovascular disease

    Institute of Scientific and Technical Information of China (English)

    辛浩琳; 杨国晶; 林丽娜; 吴扬

    2007-01-01

    目的:探讨低能量He-Ne激光血管内照射合血府逐瘀胶囊治疗缺血性脑血管病后抑郁状态的疗效观察.方法:将60例患者随机分为两组,治疗组(30例)和对照组(30例).治疗组采用低能量He-Ne激光血管内照射配合血府逐瘀胶囊治疗,对照组则采用抗抑郁药物百忧解.用HAMD评分标准和临床总体印象量表(CGI)评定疗效.结果:治疗组有效率为93.3%,对照组为73.3%,治疗组疗效明显优于对照组(P《0.05).结论:低能量He-Ne激光血管内照射合血府逐瘀胶囊能有效缓解情感障碍,对控制抑郁状态有显著的疗效.

  4. Clinical nursing observation on the He-Ne Lasers plus Anti-inflammatory muscle cream in the treatment of the chronic ulcer of lower limb%氦氖激光联合消炎生肌膏治疗下肢慢性溃疡临床护理观察

    Institute of Scientific and Technical Information of China (English)

    魏娟; 闵庆莲

    2013-01-01

    目的 探讨氦氖激光联合消炎生肌膏治疗下肢慢性溃疡的临床疗效.方法 将84例下肢慢性溃疡患者随机分为两组,观察组42例,对照组42例,对照组患者常规碘伏消毒创面及雷夫奴尔敷料覆盖包扎.观察组患者碘伏消毒创面后先用氦氖激光照射,再涂以消炎生肌膏,将两组疗效进行观察比较.结果 观察组总有效率为 95.24%,对照组总有效率为 83.33%,观察组疗效明显高于对照组,差异有统计学意义(P<0.05),观察组愈合时间明显低于对照组,差异具有显著统计学意义(P<0.01).结论氦氖激光照射联合消炎生肌膏治疗下肢慢性溃疡,疗效显著,具有临床推广应用价值.

  5. [Lasers].

    Science.gov (United States)

    Passeron, T

    2012-11-01

    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  6. Lasers.

    Science.gov (United States)

    Passeron, T

    2012-12-01

    Lasers are a very effective approach for treating many hyperpigmented lesions. They are the gold standard treatment for actinic lentigos and dermal hypermelanocytosis, such as Ota nevus. Becker nevus, hyperpigmented mosaicisms, and lentigines can also be successfully treated with lasers, but they could be less effective and relapses can be observed. However, lasers cannot be proposed for all types of hyperpigmentation. Thus, freckles and café-au-lait macules should not be treated as the relapses are nearly constant. Due to its complex pathophysiology, melasma has a special place in hyperpigmented dermatoses. Q-switched lasers (using standard parameters or low fluency) should not be used because of consistent relapses and the high risk of post-inflammatory hyperpigmentation. Paradoxically, targeting the vascular component of the melasma lesion with lasers could have a beneficial effect. However, these results have yet to be confirmed. In all cases, a precise diagnosis of the type of hyperpigmentation is mandatory before any laser treatment, and the limits and the potential side effects of the treatment must be clearly explained to patients. Copyright © 2012 Elsevier Masson SAS. All rights reserved.

  7. Quantum and Classical Effects in the Two-Frequency Kicked Rotor with Variable Initial Phase

    CERN Document Server

    Mullins, T G; Sadgrove, M P; Hoogerland, M D; Parkins, A S; Leonhardt, R

    2004-01-01

    We present an investigation into effects exhibited by the two-frequency kicked rotor. Experiments were performed and in addition quantum and classical dynamics were simulated and compared with the experimental results. The experiments involved pulsing the optical standing wave with two pulsing periods of differing frequencies and variable initial phase offset. The ratio of pulsing periods was sampled for rational and irrational values for different experimental runs. In this paper we present these results and examine the measured momentum distributions for the cause of any structures that are seen in the energy as the initial phase offset is changed. Irrational ratios exhibit no significant quantum effects, whereas rational ratios show dynamical localisation (DL) for certain values of the initial phase. However, most of the observed structure is found to be due to classical effects, in particular KAM boundaries, and is therefore not of uniquely quantum origin.

  8. A new method using orthogonal two-frequency grating in online 3D measurement

    Science.gov (United States)

    Peng, Kuang; Cao, Yiping; Wu, Yingchun; Lu, Mingteng

    2016-09-01

    In online 3D measurement, a new method using orthogonal two-frequency grating based on Phase Measuring Profilometry(PMP) is proposed. The modulation of the entire measured object is used to match pixels and this proposed method successfully resolves the contradiction of the demand for different frequency fringes between the extraction of the modulation information and the phase unwrapping. The high-frequency fringe is used to catch the better modulation patterns for pixel matching, and the low-frequency fringe is used to calculate the phase distribution and avoid phase unwrapping error. In addition, to extract the better modulation patterns for pixel matching, the flat filtering window replaces the circular filtering window to avoid the spectrum aliasing phenomenon. The simulations and experiments show its feasibility.

  9. Propagation of the two-frequency coherence function in an inhomogeneous background random medium

    Science.gov (United States)

    Kalugin, Alexander; Bronshtein, Alexander; Mazar, Reuven

    2004-07-01

    The spatial and temporal structures of time-dependent signals can be appreciably affected by random changes of the parameters of the medium characteristic of almost all geophysical environments. The dispersive properties of random media cause distortions in the propagating signal, particularly in pulse broadening and time delay. When there is also spatial variation of the background refractive index, the observer can be accessed by a number of background rays. In order to compute the pulse characteristics along each separate ray, there is a need to know the behaviour of the two-frequency mutual coherence function. In this work, we formulate the equation of the two-frequency mutual coherence function along a curved background ray trajectory. To solve this equation, a recently developed reference-wave method is applied. This method is based on embedding the problem into a higher dimensional space and is accompanied by the introduction of additional coordinates. Choosing a proper transform of the extended coordinate system allows us to emphasize 'fast' and 'slow' varying coordinates which are consequently normalized to the scales specific to a given type of problem. Such scaling usually reveals the important expansion parameters defined as ratios of the characteristic scales and allows us to present the proper ordering of terms in the desired equation. The performance of the main order solution is demonstrated for the homogeneous background case when the transverse structure function of the medium can be approximated by a quadratic term. This article is dedicated to the memory of Professor Reuven Mazar, a top notch scientist, whose creativity influenced many random media researchers. Professor Mazar passed away suddenly a few weeks before the publication of this paper.

  10. Influence of low-intensity laser radiation on the dynamics of some phytohormone content in the callus tissues of wheat Triticum aestivum L.

    Science.gov (United States)

    Dudareva, L. V.; Rudikovskaya, E. G.; Shmakov, V. N.; Rudikovskii, A. V.; Salyaev, R. K.

    2017-05-01

    We carried out an analysis of the influence of low-intensity He-Ne laser radiation on the dynamics of changes observed in the content of the phytohormones abscisic, jasmonic, salicylic, and indoleacetic acids in wheat calluses of Triticum aestivum L. using chromatography-mass spectrometry. He-Ne laser irradiation (λ  =  632.8 nm) in its stimulant dose (3.5 J cm-2) was proved to cause a decrease in jasmonic and indoleacetic acid content and, simultaneously, a significant (2.5-3 times) increase in ‘stress’ abscisic and salicylic acids. The response of jasmonic acid to He-Cd laser irradiation (λ  =  441 nm) was specific, which is probably due to the blue-light-induced biosynthesis of the acid. This article discusses a possible connection between substantial changes in growth regulator content within the plant tissue under the influence of low-intensity laser irradiation and the stress character of this type of radiation.

  11. Influence of low-intensity laser radiation on degree of oxygenation and speed microcirculation of blood

    Science.gov (United States)

    Korolevich, Alexander N.; Dubina, Natali S.; Vecherinski, Sergei I.

    2000-11-01

    The paper investigated in vivo the influence of low-intensity laser radiation (he-Ne laser with wavelength 0,63 nm) on the mean velocity of their movement. It is known that characteristic of cardiovascular diseases (CVD) are microcirculation disturbances and disorder in rheological properties of blood. Therefore these investigations were carried out on cardiac ischemia patients. The blood perfusion valve and the mean velocity were measured by the method of photon correlation spectroscopy with the use of fiber optic cables. As the radiation source, a semiconductor laser with wavelength 780 nm (0,8 mW) was used. It has been found that, between the erythrocytes and the mean velocity of their movement there is an inverse dependence on the time of irradiation of patients.

  12. OCT imaging with temporal dispersion induced intense and short coherence laser source

    Science.gov (United States)

    Manna, Suman K.; le Gall, Stephen; Li, Guoqiang

    2016-10-01

    Lower coherence length and higher intensity are two indispensable requirements on the light source for high resolution and large penetration depth OCT imaging. While tremendous interest is being paid on engineering various laser sources to enlarge their bandwidth and hence lowering the coherence length, here we demonstrate another approach by employing strong temporal dispersion onto the existing laser source. Cholesteric liquid crystal (CLC) cells with suitable dispersive slope at the edge of 1-D organic photonic band gap have been designed to provide maximum reduction in coherence volume while maintaining the intensity higher than 50%. As an example, the coherence length of a multimode He-Ne laser is reduced by more than 730 times.

  13. Applications of high power lasers. [using reflection holograms for machining and surface treatment

    Science.gov (United States)

    Angus, J. C.

    1979-01-01

    The use of computer generated, reflection holograms in conjunction with high power lasers for precision machining of metals and ceramics was investigated. The Reflection holograms which were developed and made to work at both optical wavelength (He-Ne, 6328 A) and infrared (CO2, 10.6) meet the primary practical requirement of ruggedness and are relatively economical and simple to fabricate. The technology is sufficiently advanced now so that reflection holography could indeed be used as a practical manufacturing device in certain applications requiring low power densities. However, the present holograms are energy inefficient and much of the laser power is lost in the zero order spot and higher diffraction orders. Improvements of laser machining over conventional methods are discussed and addition applications are listed. Possible uses in the electronics industry include drilling holes in printed circuit boards making soldered connections, and resistor trimming.

  14. Investigation of tissue oxygenation by in vivo laser-induced photodissociation of cutaneous arterial blood oxyhemoglobin

    Science.gov (United States)

    Asimov, M. M.; Korolevich, A. N.

    2008-06-01

    A novel method of direct control of local tissue oxygenation based on laser-induced photodissociation of oxyhemoglobin in cutaneous blood vessels is discussed. New technology in selective and local increase of the concentration of free molecular oxygen in tissue that enhances metabolism of cells is demonstrated. Direct in vivo measurements of the tissue oxygen tension are carried out on human skin. Kinetics of oxygen tension in tissue is investigated under the effect of He-Ne laser radiation at the power of 1mW relatively to initial value of tissue oxygen tension. The results of experimental study the kinetics of oxygen distribution into tissue from arterial blood is presented. Biomedical applications of proposed new technology in laser therapy of pathologies where elimination of local tissue hypoxia is critical are discussed.

  15. Athermal Annealing of Semiconductors Using Shock Waves Generated by a Laser-Plasma

    Science.gov (United States)

    Fischer, R. P.; Grun, J.; Mignogna, R.; Donnelly, D. W.; Covington, B.

    2004-07-01

    We are investigating an annealing technique in which shock or sound waves generated by a laser-plasma are used to anneal a semiconductor. The athermal annealing (AA) process occurs very rapidly, which results in almost no diffusion of. dopants. A HeNe laser is used to measure the reflectivity of the silicon as a function of time. Measurements show that the annealing occurs in 1.8 μsec, which is the acoustic time scale for waves to propagate from the focus through the AA region. A knife-edge technique is employed to study acoustic waves in the sample by measuring the deflection of the probe beam. Initial results for aluminum samples irradiated at modest laser intensities (200 mJ, 50 nsec) show well-defined surface acoustic waves. However, both silicon and GaAs have more complicated structure which resemble Lamb (plate) waves.

  16. A low cost scheme for high precision dual-wavelength laser metrology

    CERN Document Server

    Kok, Yitping; Robertson, J Gordon; Tuthill, Peter G; Warrington, Benjamin A; Tango, William J

    2013-01-01

    A novel method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dual-wavelength metrology which employs heterodyne detection, the method developed in this work utilizes direct detection of interference fringes of two He-Ne lasers as well as a less precise stepper motor open-loop position control system to perform its measurement. Although the method may be applicable to a variety of circumstances, the specific application where this metrology is essential is in an astrometric optical long baseline stellar interferometer dedicated to precise measurement of stellar positions. In our example application of this metrology to a narrow-angle astrometric interferometer, measurement of nanometer precision could be achieved without frequency-stabilized lasers although the use of such lasers would extend the range of optical path length the metrology can accurately measure. Implementation of the method requires very little additional optics or el...

  17. Study on improvement of the laser uniformity transformation of overlapping-image waveguide cavity

    Institute of Scientific and Technical Information of China (English)

    Zebin Fan; Junchang Li; Chongguang Li; Kun Ma

    2005-01-01

    @@ After propagating through the overlapping-image integral mirror, the interference fringe is a major factor that affects the uniformity of the image plane. In this paper, a He-Ne laser is used as light source, and the complex amplitude of the incident laser beam is modulated by an alternating electric field controlled vibrating mirror that is placed before the optical system. The experimental results show that after propagating through the overlapping-image integral mirror, not only the contrast of the interference fringes on the image plane is depressed, but also the uniformity of the intensity distribution of the transformed light beam is improved. Finally, based on the experimental results, two optical systems that can be applied to high power laser uniformity transformation are presented.

  18. Laser Science and Applications

    Science.gov (United States)

    El-Nadi, Lotfia M.; Mansour, Mohy S.

    2010-04-01

    Attosecond high harmonic pulses: generation and characterization / C. H. Nam and K. T. Kim -- High power lasers and interactions / C. Chatwin and R. Young -- Laser accelerators / L. M. El-Nadi ... [et al.] -- Energy levels, oscillator strengths, lifetimes, and gain distributions of S VII, CI VIII, and Ar IX / Wessameldin. S. Abdelaziz and Th. M. El-Sherbini -- The gain distribution according to theoretical level structure and decay dynamics of W[symbol] / H. M. Hamed ... [et al.] -- Raman spectroscopy and low temperature photoluminescence ZnSe[symbol]Te[symbol] ternary alloys / A. Salah ... [et al.] -- Automated polarization-discrimination technique to minimize lidar detected skylight background noise, part I / Y. Y. Hassebo, K. Elsayed and S. Ahmed -- Laser interferometric measurements of the physical properties for He, Ne gases and their mixture / N. M. Abdel-Moniem ... [et al.] -- Analytical studies of laser beam propagation through the atmosphere / M. I. El-Saftawy, A. M. Abd El-Hamed and N. Sh. Kalifa -- Laser techniques in conservation of artworks: problems and breakthroughs / R. Salimbeni and S. Siano -- Technology-aided heritage conservation laser cleaning for buildings / M. S. Nada -- Technology significance in conservation of the built heritage 3D visualization impact / M. S. Nada -- Simulation of optical resonators for Vertical-Cavity Surface-Emitting Lasers (VCSEL) / M. S. Mansour ... [et al.] -- Optical design alternatives: a survey study / A. A. K. Ismail, I. A. S. Ismail and S. H. Ahmed -- Materials for digital optical design; a survey study / A. A. K. Ismail, I. A. S. Ismail and S. H. Ahmed -- Proposed design for optical digital circuits / A. A. K. Ismail, I. A. S. Ismail and S. H. Ahmed -- Photo-induced effect on bacterial cells / M. H. El Batanouny ... [et al.] -- Laser and non-coherent light effect on peripheral blood normal and acute lymphoblastic leukemic cells by using different types of photosensitizers / M. H. El Batanouny ... [et al

  19. Laser biostimulation (Ne-He and Ga-As) effects as compared to the conventional therapy in several pelvic inflammatory diseases

    Science.gov (United States)

    Antipa, Ciprian; Dona, Dumitru; Podoleanu, Adrian Gh.; Crisan, Nicolae; Constantinescu, Camelia

    1993-05-01

    We studied the effects of the very low-power Gallium-Arsenic infrared semiconductor laser and low-power Helium-Neon laser irradiation, single or in combination, compared to the placebo and conventional therapy on the recovery of 118 female patients from our hospital with the diagnosis of chronic pelvic inflammatory disorders. Laser biostimulation therapy proved to be significantly more efficient as compared with placebo or conventional therapy. The most efficient of all kinds of irradiations was the combination between He-Ne and Ga-As (laserpuncture and scanning). After laser treatments we didn't find any significant local genital changes both at the bimanual examination (except provoked pain), and at the echographical examination. Soft and very low-power laser therapy can be a useful alternative to the conventional treatments for pelvic inflammatory diseases.

  20. Effects of low-intensity polarized visible laser radiation on skin burns: a light microscopy study.

    Science.gov (United States)

    Ribeiro, Martha Simões; Da Silva, Daniela De Fátima Teixeira; De Araújo, Carlos Eugênio Nabuco; De Oliveira, Sérgio Ferreira; Pelegrini, Cleusa Maria Raspantini; Zorn, Telma Maria Tenório; Zezell, Denise Maria

    2004-02-01

    This study was carried out to investigate the influence of low-intensity polarized visible laser radiation on the acceleration of skin wound healing. Low-level laser therapy (LLLT) at adequate wavelength, intensity, and dose can accelerate tissue repair. However, there is still unclear information about light characteristics, such as coherence and polarization. Some studies indicate that linearly polarized light can survive through long propagation distance in biological tissue. Three burns about 6 mm in diameter were created on the back of rats with liquid N(2). Lesion "L(//)" was irradiated by He-Ne laser (lambda = 632.8 nm), D= 1.0 J/cm(2), with linear polarization parallel to the spinal column of the rat. Lesion "L(inverted v)" was irradiated using the same laser and dose, but the light polarization was aligned perpendicularly to the relative orientation. Lesion "C" was not irradiated in order to be considered as control. The animals were sacrificed at day 3-17 after lesion creation. Samples were collected and prepared for histological analysis. Histological analysis showed that the healing of irradiated wounds was faster than that of non-irradiated wounds. Moreover, it was observed that skin wound repair is dependent on polarization orientation with respect to a referential axis as the animal's spinal column. Consequently, "L(//)" was completely healed after 17 days, whereas "L (perpendicular) " showed a moderate degree of healing after the same period. These results indicate that the relative direction of the laser polarization plays an important role in the wound healing process when highly coherent He-Ne laser is used.

  1. Precise force measurement method by a Y-shaped cavity dual-frequency laser

    Institute of Scientific and Technical Information of China (English)

    Guangzong Xiao; Xingwu Long; Bin Zhang; Geng Li

    2011-01-01

    A novel precise force measurement based on a Y-shaped cavity dual-frequency laser is proposed. The principle of force measurement with this method is analyzed, and the analytic relation expression between the input force and the change in the output beat frequency is derived. Experiments using a 632.8-nm Y-shaped cavity He-Ne dual-frequency laser are then performed; they demonstrate that the force measurement is proportional to a high degree over almost five decades of input signal range. The maximum scale factor is observed as 5.02×109 Hz/N, with beat frequency instability equivalent resolution of 10-5 N. By optimizing the optical and geometrical parameters of the laser sensor, a force measurement resolution of 10-6i N could be expected.%A novel precise force measurement based on a Y-shaped cavity dual-frequency laser is proposed.The principle of force measurement with this method is analyzed,and the analytic relation expression between the input force and the change in the output beat frequency is derived.Experiments using a 632.8-nm Y-shaped cavity He-Ne dual-frequency laser are then performed;they demonstrate that the force measurement is proportional to a high degree over almost five decades of input signal range.The maximum scale factor is observed as 5.02× 109 Hz/N,with beat frequency instability equivalent resolution of 10-5 N.By optimizing the optical and geometrical parameters of the laser sensor,a force measurement resolution of 10 -6 N could be expected.Precise measurement of force and force-related nagnitudes,such as acceleration,pressure,and mass,is an often demanded task in modern engineering and science[1-3].In recent decades,some research efforts have been intensified to utilize optical measnrement procedures for obtaining precise force measurement.

  2. An in vivo comparison of two frequency-based electronic apex locators.

    Science.gov (United States)

    Welk, Aaron R; Baumgartner, J Craig; Marshall, J Gordon

    2003-08-01

    The purpose of this study was to compare the accuracy of a two-frequency (Root ZX) and a five-frequency (Endo Analyzer Model 8005) electronic apex locator under clinical conditions. Thirty-two teeth planned for extraction were used. The coronal portion of each canal was flared using Gates Glidden drills and Orifice Shapers. The canals were irrigated with 2.6% sodium hypochlorite. A K-type file was used to determine a separate working length in each canal using the electronic apex locators. The teeth were extracted and the apical 4 mm of each root canal was exposed along the long axis of the tooth. Photographic slides of each canal were projected and the file position in relation to the minor diameter was determined by two investigators. The mean distance between the electronic apex locator working length and minor diameter was 1.03 mm for the Endo Analyzer and 0.19 mm for the Root ZX. A paired sample t test showed that the Endo Analyzer had significantly longer readings beyond the minor diameter than the Root ZX (p locate the minor diameter (+/- 0.5 mm) was 90.7% for the Root ZX and 34.4% for the Endo Analyzer Model 8005.

  3. Parametrically Excited Surface Waves Two-Frequency Forcing, Normal Form Symmetries, and Pattern Selection

    CERN Document Server

    Silber, M; Silber, Mary; Skeldon, Anne C.

    1999-01-01

    Motivated by experimental observations of exotic standing wave patterns in the two-frequency Faraday experiment, we investigate the role of normal form symmetries in the pattern selection problem. With forcing frequency components in ratio m/n, where m and n are co-prime integers, there is the possibility that both harmonic and subharmonic waves may lose stability simultaneously, each with a different wavenumber. We focus on this situation and compare the case where the harmonic waves have a longer wavelength than the subharmonic waves with the case where the harmonic waves have a shorter wavelength. We show that in the former case a normal form transformation can be used to remove all quadratic terms from the amplitude equations governing the relevant resonant triad interactions. Thus the role of resonant triads in the pattern selection problem is greatly diminished in this situation. We verify our general results within the example of one-dimensional surface wave solutions of the Zhang-Vinals model of the t...

  4. Laser and Non-Coherent Light Effect on Peripheral Blood Normal and Acute Lymphoblastic Leukemic Cells by Using Different Types of Photosensitizers

    Science.gov (United States)

    El Batanouny, Mohamed H.; Khorshid, Amira M.; Arsanyos, Sonya F.; Shaheen, Hesham M.; Abdel Wahab, Nahed; Amin, Sherif N.; El Rouby, Mahmoud N.; Morsy, Mona I.

    2010-04-01

    Photodynamic therapy (PDT) is a novel treatment modality of cancer and non-cancerous conditions that are generally characterized by an overgrowth of unwanted or abnormal cells. Irradiation of photosensitizer loaded cells or tissues leads via the photochemical reactions of excited photosensitizer molecules to the production of singlet oxygen and free radicals, which initiate cell death. Many types of compounds have been tested as photosensitizers, such as methylene blue (MB) and photopherin seemed to be very promising. This study involved 26 cases of acute lymphoblastic leukemia and 15 normal volunteers as a control group. The cell viability was measured by Light microscope and flowcytometer. Mode of cell death was detected by flowcytometer and electron microscope in selected cases. The viability percentage of normal peripheral blood mononuclear cells (PBMC) incubated with methylene blue (MB) alone or combined with photo irradiation with diode laser (as measured by light microscope) was significantly lower than that of untreated cases either measured after 1 hour (pdecrease in viability was more enhanced with increasing the incubation time. For normal cells incubated with photopherin either for 1/2 an hour or 1 hour, there was a weak cytotoxic effect compared to the effect on untreated cells. There was a significant decrease in viability percentage of cells incubated with photopherin either for 1/2 an hour or 1 hour and photoirradiated with He:Ne laser compared to normal untreated cells. The decrease in the cell viability percentage was significantly lower with the use of PDT (photopherin and He:Ne laser ) compared to either photopherin alone or He:Ne laser alone. The decrease in viability was more enhanced with increasing the incubation time. The same effects reported on normal cells were detected on leukemic cells on comparing different methods used. However a more pronounced decrease in cell viability was detected. The most efficient ways of decreasing viability

  5. Effect of bone marrow and low power lasers on fracture healing with destruction of both periosteum and endosteum in rabbits

    Directory of Open Access Journals (Sweden)

    M. G. Thanoon

    2010-01-01

    Full Text Available Ten mature rabbits of local breed were used in this study; weighing between 1.5 to 1.75 kg and aged about 1–2 years. These animals were divided into two equal groups; in group A destruction of both periosteum and endosteum was done one centimeter from each side of mid-shaft femoral bone fracture, then sufficient amount of autogenously bone marrow was injected directly at the fracture site after immobilization by intramedullary pin. In group B a similar procedure was achieved as in group A, but in additional to that He-Ne infrared laser therapy was used for several sessions. The result of radiological findings indicated that, the fracture healing occurred within group B at fifteen weeks, whereas in group A the healing occurred at eighteen weeks after operation. The implantation of autologous bone marrow enhanced the fracture healing, whereas using of combinations of autologous bone marrow and He-Ne infrared laser therapy hastened the healing.

  6. Athermal laser treatment of the diabetic leg

    Science.gov (United States)

    Ignat, P.; Suteanu, S.; Brojbeanu, Gabriela; Vasiliu, Virgil V.

    1995-03-01

    This work shows the result obtained in the medical clinic of the `Dr. I. Cantacuzino Hospital' on a lot of 43 diabetic patients using the `LASSIS' devices composed of a He-Ne laser and 4 semiconductor lasers. The 43 patients showed various clinic pictures of a diabetic leg (diabetic arteriopathy and neuropathy) 16 of the lot showed an arteriopathy with claudication and a decrease of pulses oscillometrically measurements, 15 had ulceration and a beginning of gangrene and the other 12 showed a plantary boring ill. There has been achieved an amelioration of the oscillometric index of the claudication while walking the amelioration of local circulation, together with the limitation of the necrosis. For the boring ill, there has been achieved the acceleration of the granulating and epithelization process avoiding surgeries, suppuration and cutaneous plasties. The response to the laser treatment was compared to the response to the classic treatment (vasodilatation surgery unstrapping, antibiotherapy) on a proving lot. We appreciated that the cicatrization and local vasodilatation with athermal laser treatment should be a hope for the treatment of patients suffering of diabetic arteriopathy and neuropathy.

  7. System design of welding dynamic displacement measurement using laser ESPI

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Based on the advantages of electronic speckle pattern interferometry(ESPI), such as non-contact, high precision, strong parasitic light resistance, and full-field measurement, a system for measuring welding dynamic displacement fields using ESPI was designed. The system consists of a 70mW He-Ne laser source, an optical path system, a computer-assisted frame grabber and a processing system. By measuring dynamic displacement fields on one LY2 aluminum alloy plate during an argon arc point welding, it can be proved that using ESPI to measure welding dynamic displacement fields is fully feasible, and this method can offer a solid experimental base for the structure mechanics.

  8. Photobiomodulation by helium neon and diode lasers in an excisional wound model: A single blinded trial

    Directory of Open Access Journals (Sweden)

    Snehil Dixit

    2012-01-01

    Full Text Available Background: Application of different kinds of lasers in clinical and experimental studies causes photobiomodulation that works at localized cellular and humoral level on various biological systems. Increased numbers of fibroblasts, myofibroblast, and degranulation of mast cells have been the observed benefits post-irradiation. Objective: Was to find out the effect of irradiation with energy densities of 3.38 J/cm 2 , 8 J/cm 2 , and 18 J/cm 2 on animal tissue (albino wistar rats in an excisional wound model and to assess changes in biochemical (hydroxyproline and histopathological levels in excisional wound model. Materials and Methods: The animals were divided into 4 groups, which were labeled as L1, diode laser (18 J/cm 2 , L2 Helium-neon (He-Ne, 8 J/cm 2 , L3 diode laser (3.38 J/cm 2 , and sham treatment for control was depicted by C, respectively. Histological and hydroxyproline analysis was performed on 7, 14, 21 days of post-wounding. One-way analysis of variance, ANOVA and Bonferroni′s multiple comparison tests were done for tissue hydroxyproline levels. Results: There was no significant increase in the hydroxyproline content (P < 0.005 when observed in study group and compared to controls. Whereas significant epithelizations was seen in group treated with He-Ne laser of intensity of 8 J/cm 2 . Conclusion: The experimental observations suggest that low intensity helium-neon laser of 8 J/cm 2 intensity facilitated photo stimulation by tissue repair, but failed to show significant tissue hydroxyproline levels in excisional wound model.

  9. Measurements of complex coupling coefficients in a ring resonator of a laser gyroscope

    Science.gov (United States)

    Bessonov, A. S.; Makeev, A. P.; Petrukhin, E. A.

    2017-07-01

    A method is proposed for measuring complex coupling coefficients in a ring optical resonator in the absence of an active gas mixture. A setup is described on which measurements are performed in ring resonators of ring He-Ne lasers with a wavelength of 632.8 nm. A model of backscattering field interference between conservative and dissipative sources is presented. Within the framework of this model, the unusual behaviour of backscattering fields in ring resonators observed in experiments is explained: a significant difference in the moduli of coupling coefficients of counterpropagating waves and variation of the magnitude of the total phase shift in a wide range. It is proposed to use this method as a metrological method when assembling and aligning a ring resonator of a laser gyroscope.

  10. Laser images recording on aerosol-synthesized single-walled carbon nanotube films

    Science.gov (United States)

    Mikheev, G. M.; Mikheev, K. G.; Anoshkin, I. V.; Nasibulin, A. G.

    2015-09-01

    It is shown that images on semitransparent conducting films of aerosol-synthesized single-walled carbon nanotubes (SWCNTs) can be recorded using focused low-power radiation of a He-Ne laser operating at a wavelength of 632.8 nm. Both free-standing films and those deposited on glass or polymer substrates can be used. Laser recording of images on the polymer-supported films is possible due to their transparency increased as a result of chemical reactions between iron nanoparticles encapsulated in SWCNTs and the products of local thermal decomposition of the polymer. Recording on the free-standing SWCNT films and those supported on glass substrates was performed upon acid treatment of the film surface.

  11. Photobiomodulation of vascular endothelial and smooth muscle cells in vitro with red laser light

    Science.gov (United States)

    Kipshidze, Nicholas; Keelan, Michael H., Jr.; Horn, Joseph B.; Nikolaychik, Victor

    1996-12-01

    Numerous reports suggest that low power red laser light (LPRLL) is capable of affecting cellular processes in the absence of significant thermal effect. The objective of the present study was to determine the effect of LPRLL on viability, growth, and attachment characteristics of rabbit and human aortic endothelial cells (EC) and smooth muscle cells (SMC) in vitro. All cell cultures were irradiated with single dose LPRLL using a He-Ne continuous wave laser with different energy densities. Assessment of effect on cell viability, growth, and attachment was performed utilizing Alamar Blue assay. Based upon our experiments, we conclude that: 1) stimulation and/or inhibition of cell growth and death can be obtained with LPRLL by varying the energy level, 2) LPRLL increases EC attachment, and 3) EC are more sensitive to photobiomodulation with LPRLL than SMC. These data may have significant importance leading to the establishment of new methods for phototherapy of atherosclerosis and restenosis.

  12. Study of mode propagation with 632.8-nm laser in tapered fiber

    Institute of Scientific and Technical Information of China (English)

    He Chen; Junliang Lu; Chengliang Zhao; Botao Cheng; Xuanhui Lu

    2009-01-01

    The material dispersion of a tapered fiber is described by Sellmeier's equation.The dependence of refractive index on wavelength and doping concentration is discussed.A He-Ne laser with the output wavelength of 632.8 nm is used in the experiment.When the cutoff frequency of the fiber is less than the laser frequency,the guiding modes of a single-mode fiber(at 1550 nm)are investigated.The results show that the original single-mode fiber becomes a multi-mode waveguide.The propagation and mode coupling of the light in the taper region are analyzed.By controlling the taper end size of the fiber,the unique tapered fiber can convert a multi-mode beam into a single-mode one.

  13. OPTICAL OPTIMIZATION FOR LIQUID CRYSTAL TEST BY LASER-CCD SYSTEM

    Institute of Scientific and Technical Information of China (English)

    Chang Ying; Zhu Henian; Zhang Ziliang; Yang Changxi

    2005-01-01

    For the narrowband of liner charge-coupled device (CCD) receiver and the imaging rule that cylindrical lens system can compress round facula into narrow and long one, the system is simplified and light force can concentrate on a strip facula. Considered the effective CCD length and selection of lens parameters, the system can be optimized. Correspondingly to the CCD pixels, the ray is composed of much angle information. By widening the parallel ray or increasing the lens aperture, luminous flux can be ensured when oblique incidence. Meanwhile, the effective working range can also be improved. Based on the experimental data, cylindrical system could be applied in accurate angle measurement. It has been proved feasible that the cylindrical system can be used in anchor behavior study for liquid crystal (LC) case. The low-power He-Ne laser cylindrical system can carry out the previous effect in high power laser spherical system.

  14. ROMY: A 4-component large ring laser for geophysics

    Science.gov (United States)

    Igel, H.; Schreiber, K. U.; Gebauer, A.; Wassermann, J. M.; Lin, C. J.; Bernauer, F.; Simonelli, A.; Wells, J. P. R.

    2016-12-01

    Observatory-based ring lasers are currently the most sensitive technology for measurements of rotational ground motions (seismology) and variations of Earth's rotation rate. Ring laser have so far been limited to single components only (e.g., the horizontal G-ring in Wettzell, Germany, measuring the rotation around a vertical axis). Within the ROMY project (www.romy-erc.eu) funded by the European Research Council we designed and constructed the first multi-component ring laser system for geophysics. The 4-component, tetrahedral-shaped, top-down ring laser sits on a connected concrete structure embedded underground 2m below the surface at the Geophysical Observatory Fürstenfeldbruck, Germany. The 4 independent equilateral triangular-shaped He-Ne ring lasers with 12 m side length are expected to resolve rotational motions below 12 prad/s/sqrt(Hz). We will report on the design and construction process of this first-of-its-kind ring laser system, with completion expected in August 2016 by which time the optical systems are beginning to be assembled. The four rotational components are combined to the complete 3-component vector of Earth's rotation, perturbed by other geophysical signals such as earthquake induced ground motions, ocean-generated noise, Earth's free oscillations, interactions between atmosphere and solid Earth and other signals. First applications are expected in the field of seismology. We report on future plans to stabilize the ring geometry providing long-term stability for geodetic applications.

  15. Influence of helium-neon laser irradiation on seed germination in vitro and physico-biochemical characters in seedlings of brinjal (Solanum melongena L.) var. Mattu Gulla.

    Science.gov (United States)

    Muthusamy, Annamalai; Kudwa, Prathibha P; Prabhu, Vijendra; Mahato, Krishna K; Babu, Vidhu Sankar; Rao, Mattu Radhakrishna; Gopinath, Puthiya Mandyat; Satyamoorthy, Kapaettu

    2012-01-01

    In the present study, the seeds of brinjal (Solanum melongena L.) var. Mattu Gulla were irradiated with single exposure of He-Ne laser at different doses of 5-40 J cm(-2) and germinated aseptically. Thirty day old seedlings were harvested and the germination, growth, physiological and biochemical parameters were estimated and compared with un-irradiated control seedlings. A significant enhancement in growth characters were noted with respect to length, fresh and dry weight of shoots and roots. In addition, chlorophyll (a and b), carotenoid content, anthocyanin and amylases (α and β) activities were found to be altered. Significant alterations in percentage of seed germination (P < 0.001) and time to 50% germination (P < 0.001) were observed in the irradiated seeds compared with the un-irradiated controls. In conclusion, the results of the present study demonstrated that low dose (5-30 J cm(-2) ) of He-Ne laser irradiation enhanced the germination process and altered growth, by positively influencing physiological and biochemical parameters of the brinjal seedlings compared with un-irradiated control under in vitro conditions.

  16. Bone fracture consolidates faster with low-power laser

    Energy Technology Data Exchange (ETDEWEB)

    Trelles, M.A.; Mayayo, E.

    1987-01-01

    Low-power laser radiation is currently used in the treatment of pain and osteoarticular inflammation. However, the mechanisms of the laser biostimulating effects on tissue are still not completely understood. With laser treatment, we have achieved activation of osseous regeneration in human bone fractures. After 7 years of positive clinical control in human beings, we decided to start an experimental study of fractures in the tibia of mice, histologically controlling its reparation after exposure to 632 nm. He/Ne laser in doses of 2.4 Joules in one point was used. The radiation was directly applied to the area of fracture in a series of 12 treatments (one treatment every second day). By optic microscope we observed, in the treated animals, an important increase in vascularization and faster formation of osseous tissue with a dense trabecular net compared to the control group, which presented only chondroid tissue and poor vascularization corresponding to an earlier stage of bone consolidation (controls were also analyzed by electron microscopy). Potentially, the laser effect might modulate the function of osteocytes, promoting faster metabolism and reaction of bone callus.

  17. Superposition of orbital angular momentum of photons by a combined computer-generated hologram fabricated in silica glass with femtosecond laser pulses

    Institute of Scientific and Technical Information of China (English)

    Guo Zhong-Yi; Qu Shi-Liang; Sun Zheng-He; Liu Shu-Tian

    2008-01-01

    This paper introduces a novel method to realize the superposition of orbital angular momentum of photons by combined computer-generated hologram (CCGH) fabricated in silica glass with femtosecond laser pulses.Firstly,the two computer-generated holograms (CGH) of optical vortex were obtained and combined as a CCGH according to the design.Then the CCGH was directly written inside glass by femtosecond laser pulses induced microexplosion without any pre-or post-treatment of the material.The vortex beams with different vortex topological charges (including new topological charges) have been restructured using a collimated He-Ne laser beam incidence to the CCGH normally.A theoretical and experimental explanation has been presented for the generations of the new topological charges.

  18. The brain-derived neurotrophic factor, nerve growth factor, neurotrophin-3, and induced nitric oxide synthase expressions after low-level laser therapy in an axonotmesis experimental model.

    Science.gov (United States)

    Gomes, Lessandra Esper Abdala; Dalmarco, Eduardo Monguilhott; André, Edison Sanfelice

    2012-11-01

    A robust body of evidence has shown that low-level laser therapy (LLLT) improves peripheral nerve regeneration. However, the biochemical background triggered in this process is not yet fully understood. The purpose of this study was to evaluate the mRNA expression of neurotrophic factors (brain-derived neurotrophic factor [BDNF], nerve growth factor [NGF], and neurotrophin-3, [NT-3]) and also an inflammatory marker (induced nitric oxide synthase [iNOS]) in an axonotmesis experimental model after low-level laser therapy. Thirty-six adult male Wistar rats (250-350 g) were subjected to right sciatic nerve crush injury, and 24 h later, the animals in the three different experimental groups (n=18) were irradiated on a daily basis with helium-neon laser (collimated HeNe laser, continuous emission, wavelength: 632.8 nm, power density: 0.5 mW/cm(2), irradiation time: 20 sec, energy density: 10 J/cm(2)) during 7, 14, and 21 consecutive days, respectively. The control group (n=18) underwent the same procedures, but with the equipment turned off. At the end of the experiments, animals were killed with an overdose of anesthesia to remove samples from the sciatic nerve lesion epicenter to determine the mRNA expression of BDNF, NGF, NT-3 and iNOS enzyme. Comparisons between groups showed that HeNe laser increased the mRNA expression of both BDNF and NGF factors after 14 days of LLLT, with peak expression at the 21st day. Increase in NT-3 mRNA expression was not observed. In addition, HeNe laser produced iNOS expression reduction, which played an important role in the inflammatory process. The reported data could have a relevant practical value because LLLT is a noninvasive procedure, and have revealed significant increase in neurotrophic factor expressions and inflammatory process reduction, opening the possibility of using LLLT as an important aid to nerve regeneration process.

  19. Effects of helium-neon laser irradiation and local anesthetics on potassium channels in pond snail neurons.

    Science.gov (United States)

    Ignatov, Yu D; Vislobokov, A I; Vlasov, T D; Kolpakova, M E; Mel'nikov, K N; Petrishchev, I N

    2005-10-01

    Intracellular dialysis and membrane voltage clamping were used to show that He-Ne laser irradiation of a pond snail neuron at a dose of 0.7 x 10(-4) J (power density 1.5 x 10(2) W/m2) increases the amplitude of the potential-dependent slow potassium current, while a dose of 0.7 x 10(-3) J decreases this current. Bupivacaine suppresses the potassium current. Combined application of laser irradiation at a dose of 0.7 x 10(-3) J increased the blocking effect of 10 microM bupivacaine on the slow potassium current, while an irradiation dose of 0.7 x 10(-4) J weakened the effect of bupivacaine.

  20. Central nervous system transplantation benefited by low-level laser irradiation

    Science.gov (United States)

    Rochkind, S.; Lubart, Rachel; Wollman, Yoram; Simantov, Rabi; Nissan, Moshe; Barr-Nea, Lilian

    1990-06-01

    Effect of low-level laser irradiation on the central nervous system transplantation is reported. Ernbryonal brain allografts were transplanted into the brain of 20 adult rats and peripheral nerve graft transplanted into the severely injured spinal cord of 16 dogs. The operated wound of 10 rats and 8 dogs were exposed daily for 21 days to lowpower laser irradiation CW HeNe laser (35 mW, 632.8 run, energy density of 30 J/cm2 at each point for rats and 70 J/cm2 at each point for dogs). This study shows that (i) the low-level laser irradiation prevents extensive glial scar formation (a limiting factor in CNS regeneration) between embryonal transplants and host brain; (ii) Dogs made paraplegic by spinal cord injury were able to walk 3-6 months later. Recovery of these dogs was effected by the implantation of a fragment of autologous sciatic nerve at the site of injury and subsequently exposing the dogs to low-level laser irradiation. The effect of laser irradiation on the embryonal nerve cells grown in tissue culture was also observed. We found that low-level laser irradiation induced intensive migration of neurites outward of the aggregates 15-22 The results of the present study and our previous investigations suggest that low-level laser irradiation is a novel tool for treatment of peripheral and central nervous system injuries.

  1. Orthogonal linear polarized lasers(Ⅲ) Applications in self-sensing

    Institute of Scientific and Technical Information of China (English)

    ZHANG Shulian; DU Wenhua; LIU Gang

    2005-01-01

    In this paper, the applications of orthogonal linear polarized lasers in self-sensing are reviewed. The properties for such a laser include the production of a new frequency in one longitudinal mode spacing, the tuning of frequency difference, the change of polarization states as cavity tuning, the control of mode competition intensity, the optical feedback, and so on. The orthogonal polarized lasers have been used as a laser nanometer ruler based on competition between two polarized lights in a HeNe laser and as a displacement measurement tool based on the optical feedback in the orthogonal polarized lasers. They are also used in the phase retardation measurement of a waveplate, the angle measurement, the vibration measurement, the pressure/force measurement, the weak magnetic field measurement,and so on. The structures of these new devices are simple and compact with the great advantages of high resolution and high accuracy.Some of these devices can trace to the source of the laser wavelength. The nanometer laser ruler is an example whose measurement range is 12 mm, resolution is 79 nm and linearity is less than 5×10- 5. The repeatability of the phase retardation measuring system of waveplate can reach 3'.

  2. [Age-related peculiarities of thymus reaction to the exposure to helium-neon laser and injured muscle alloplasty with the muscle tissue from the animals of the same age].

    Science.gov (United States)

    Bulyakova, N V; Azarova, V S

    2015-01-01

    Histological, cytological and morphometric changes in the thymus of 1 month-old, adult (3-4 months-old) and old (24-30 months-old) rats (24 animals in each group) were studied during muscle regeneration after the alloplasty of the injured area with the muscle tissue from the animal of the same age. Muscles of the donor or recipient were subjected to the course of preliminary irradiation with He-Ne laser (dose: 4.5-5.4 J/cm2 for each extremity; total dose of 9.0-10.8 J/cm2 per animal). It was shown that the exposure of gastrocnemius muscles that were prepared for the operation to He-Ne laser radiation decreased morpho-functional activity of the thymus in young, adult and old recipient rats the before surgery. This was demonstrated by its weaker reaction to the allograft during the early time intervals after surgery. The observed effect was more pronounced with the increasing age of an animal.

  3. Experimental basis of laser therapy in pharynx pathology

    Science.gov (United States)

    Toropova, Lyudmila A.; Fedyukovich, Lyudmila V.; Egorova, Alla B.

    1998-07-01

    Membrane-damaging action of laser irradiation comparing with membranotoxic activity of model xenobiotics (Novocain and Acrylamide) has been evaluated in our experiments using Rosette-Forming Ability test (RFA) on rat blood lymphocytes, thymocytes, splenocytes for the assessment of membrane- mediated and receptor-mediated immune cells interactions. Infra-red laser irradiation (80 and 1500 Hz, 0.89 mkM) in vivo induced 2-fold increase of lymphocytes capable to form specific rosettes with xenogenous erythrocytes. T-lymphocytes were greatly sensitive to the laser influence. Acute laser exposure (128 sec) induced changes similar to Novocain action (1/2 LD50). Five-fold increase of the laser exposure time (especially for low frequency regime) resulted in more prominent changes in intercellular communication which were found to be similar to the action of Acrylamide (1/2 LD50). B-lymphocytes and splenocytes have been assumed as target cells for the action of laser with the frequency of 1500 Hz. Course application of IR or He-Ne laser induced decrease of RFA for all immune cells tested, and for blood lymphocytes, respectively. Thus, laser-induced changes in immune cells interaction may be connected with reversible injury of cell surface membrane followed by the dysregulation of cellular communication. Based on experimental data, the optimal regime of IR laserotherapy (0.89 and 0.63 micrometer) was chosen for the treatment of 200 patients with chronic decompensated tonsillitis. Efficiency of laser application was confirmed by cytological analysis of lacunes, laserodopplerofluometria, vegetative nervous system evaluation etc. and was found to be dependent on membranotropic activity of laser irradiation.

  4. Wavelet-based multifractal analysis of laser biopsy imagery

    CERN Document Server

    Jagtap, Jaidip; Panigrahi, Prasanta K; Pradhan, Asima

    2011-01-01

    In this work, we report a wavelet based multi-fractal study of images of dysplastic and neoplastic HE- stained human cervical tissues captured in the transmission mode when illuminated by a laser light (He-Ne 632.8nm laser). It is well known that the morphological changes occurring during the progression of diseases like cancer manifest in their optical properties which can be probed for differentiating the various stages of cancer. Here, we use the multi-resolution properties of the wavelet transform to analyze the optical changes. For this, we have used a novel laser imagery technique which provides us with a composite image of the absorption by the different cellular organelles. As the disease progresses, due to the growth of new cells, the ratio of the organelle to cellular volume changes manifesting in the laser imagery of such tissues. In order to develop a metric that can quantify the changes in such systems, we make use of the wavelet-based fluctuation analysis. The changing self- similarity during di...

  5. Laser therapy in wound healing associated with diabetes mellitus - Review*

    Science.gov (United States)

    de Sousa, Raquel Gomes; Batista, Keila de Nazaré Madureira

    2016-01-01

    The article discusses the results of a literature review on the application of low intensity laser therapy on the healing of wounds associated diabetes mellitus in the last 10 years. Objective To determine the most effective parameter in healing wounds related to diabetes mellitus, as well as the most widely used type of laser. Methodology consisted of bibliographic searching the databases Bireme, SciELO, PubMed/Medline and Lilacs by using the keywords related to the topic. Were selected from these keywords, papers discussing the use of laser on wounds associated with diabetes, published in the period 2005-2014, in Portuguese or English. Results After analyzing the research, 12 studies consistent with the theme were selected. Conclusion Based on this review, the studies that showed more satisfactory results in healing diabetic wounds were those who applied energy densities in the range of 3-5 J/cm2, power densities equal to or below 0.2 W/cm2 and continuous emission. The He-Ne laser with a wavelength of 632.8 nm was used more often. PMID:27579745

  6. Helium-neon laser treatment transforms fibroblasts into myofibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Pourreau-Schneider, N.; Ahmed, A.; Soudry, M.; Jacquemier, J.; Kopp, F.; Franquin, J.C.; Martin, P.M. (CNRS Unite 1175, Marseille (France))

    1990-07-01

    The differentiation of myofibroblastic cells from normal human gingival fibroblasts in vitro has been established by transmission electron microscopy and quantitated by immunohistochemistry, using antigelsolin monoclonal antibodies. Untreated control cultures were compared to cultures exposed to Helium-Neon (He-Ne) laser irradiation. A direct and massive transformation of the cultured fibroblasts into myofibroblasts was observed as early as 24 hours after laser treatment, whereas control cultures were comprised of only resting fibroblasts and active fibroblasts. This in vitro induction of myofibroblasts may be analogous to that which occurs in vivo. Therefore we undertook a similar study using biopsies from gingival tissues after wisdom tooth extraction. Myofibroblasts were present in the connective tissue of laser-treated gums 48 hours after irradiation, but not in untreated contralateral control tissues. These data provide evidence that the primary biologic effect of the Helium-Neon laser on connective tissue is the rapid generation of myofibroblasts from fibroblasts. The induction of a phenotype with contractile properties may have clinical significance in the acceleration of the wound-healing process.

  7. Observation of plasma motion in a coaxial plasma opening switch with a chordal laser interferometer

    Energy Technology Data Exchange (ETDEWEB)

    Teramoto, Y.; Urakami, H.; Akiyama, H. [Kumamoto Univ., Graduate School of Science and Technology, Kumamoto (Japan); Kohno, S. [Ariake National College of Technology, Dept. of Electrical Engineering, Fukuoka (Japan); Katsuki, S. [Kumamoto Univ., Dept. of Electrical and Computer Engineering, Kumamoto (Japan)

    2002-06-01

    Electron densities in a coaxial plasma opening switch were measured at many lines-of-slight. In the present experiment, electron density was measured by a He-Ne laser interferometer with chordal lines-of sight. In order to observe the motion of the POS plasma, the electron density contours during the conduction, opening and post-opening phases were drawn by combining the results of interferometer experiments. The radial and axial motion of POS plasma was investigated from the density contours. As conduction time progressed, the POS plasma moved toward downstream. At 800 ns, which corresponds to the time of opening in the current waveform, low-density region less than 10{sup 15} cm{sup -2} is seen at 10 mm from the cathode. After the opening was completed, the low-density gap disappeared and the shape of the corn-shape-like plasma was distorted. (author)

  8. Treatment of Infantile Diarrhea by Acupuncture and Laser Irradiation - A Report of 60 Cases

    Institute of Scientific and Technical Information of China (English)

    丁渡明

    2004-01-01

    @@ Infantile diarrhea is a common disease in babies of less than 2 years old in summer or autumn. It is due to acute dyspepsia mainly caused by improper feeding or attack of cold or damp pathogens.Clinically, it is characterized by increased times of defecation (5-6, or even dozens of times a day),yellow-green or blue-green thin feces intermingled with mucus, milk-mass and indigested food which have a sour and fetid odor, accompanied with loss of appetite, abdominal distending pain, nausea,vomiting, and even fever, irritability, dehydration and electrolyte disturbance in severe cases. The microscopy reveals that there are leukocytes and fat globules in feces. We have treated 60 cases of infantile diarrhea with acupuncture and He-Ne laser point irradiation and obtained satisfactory therapeutic results.

  9. Variation of spatial soliton in liquid crystals due change of polarization of the incident laser beam

    Science.gov (United States)

    Rodríguez-Rosales, A. A.; Román Moreno, C. J.; Ortega-Martínez, R.

    2013-11-01

    We present experimental evidence obtained in the generation and variation of dark to bright optical spatial solitons due the change of polarization plane of He-Ne laser beam incident in the sample of liquid crystals 5CB doped with methyl red at 0.1% wt inside a cell of 15 μm widths. This work is based in previous papers about the variation of nonlinear refraction index γ in liquid crystals, where we have demonstrated that under certain conditions it is possible to realize inversion of γ, from γ > 0 to γ system that will generate in the same material a controlled dark or bright spatial optical solitons. We consider this new phenomena very important and as well as its potential technological application in all-optical switching in telecommunications and optoelectronic.

  10. The dynamic properties of shock-waves formed during laser ablation at sub-atmospheric pressures

    Science.gov (United States)

    Kapitan, D.; Coutts, D. W.

    2002-01-01

    The Sedov-Taylor-von Neumann (STN) theory has been shown to accurately describe the dynamic properties of shock-waves generated during pulsed-laser ablation of solid aluminium targets at visible wavelengths (510/578 nm) with 40 ns pulses with energies up to 3.5 mJ. A ballistic pendulum is used to measure the integrated recoil pressure in various inert atmospheres (He, Ne, Ar, Kr, Xe, N2, CO2, SF6) with pressures of 10-2 - 103 mbar. This recoil momentum is found to scale linearly with the background gas pressure P1 and with the square root of the molecular weight M1. More interestingly, the scaling with the ratio of heat capacities γ is verified to be a monotonically increasing function dependent on the form factor of the shock-wave. The validity of a modified STN theory which accounts for the piston mass is assessed.

  11. Laser light induced modulations in metabolic activities in human brain cancer

    Science.gov (United States)

    Tata, Darrell B.; Waynant, Ronald W.

    2008-03-01

    The role of low visible or near infra-red laser intensity in suppressing metabolic activity of malignant human brain cancer (glioblastoma) cells was investigated through the application of either a continuous wave 633nm HeNe or a pulsed picosecond 1,552nm wavelength laser. Human glioblastomas were exposed in their growth culture medium with serum for several energy doses. For both types of laser exposures the glioblastomas exhibited a maximal decline in the metabolic activity relative to their respective sham control counterparts at 10 J/cm2. The cellular metabolic activities for various treatment doses were measured through the colorimetric MTS metabolic assay after the laser exposure. Interestingly, addition of (the enzyme) catalase in the growth medium prior to the laser exposure was found to diminish the laser induced metabolic suppression for all fluence treatment conditions, thus suggesting a functional role of H IIO II in the metabolic suppression. Taken together, our findings reveal that visible or near infra-red low level light exposures could potentially be a viable tool in reducing the metabolic activity of cancers; evidence at hand implicates a role of light induced H IIO II in bringing about in part, suppression in the metabolic activity. Due to the cellular "biphasic" response to the laser exposure, further research needs to be undertaken to determine exposure parameters which would optimize metabolic and cellular growth suppression in-vivo.

  12. Laser Doppler flowmetry for bone blood flow measurements: helium-neon laser light attenuation and depth of perfusion assessment.

    Science.gov (United States)

    Nötzli, H P; Swiontkowski, M F; Thaxter, S T; Carpenter, G K; Wyatt, R

    1989-01-01

    Laser Doppler flowmetry (LDF) has been successfully used in clinical and experimental settings to evaluate bone perfusion but unanswered questions regarding its capabilities and limitations still remain. This study was undertaken to determine absorption of He-Ne laser light (632.8 nm) and maximum depth for flow assessment (threshold thickness) under optimal conditions in bone. Light transmittance in bovine bone samples of femora and tibia was measured after each step of grinding and depth of penetration calculated. The threshold thickness was obtained by placing the same samples in a flow chamber where a solution of 2% latex circulated beneath; flow was detected by a laser Doppler probe resting on top of the sample. The results showed a significantly higher depth of penetration for trabecular than for cortical bone. A regression analysis showed a high correlation between the inorganic fraction of the bone and the depth of penetration. The maximum depth at which the laser Doppler probe can evaluate flow in bone conditions was found to be 2.9 +/- 0.2 mm in cortical bone, 3.5 +/- 0.3 mm in bone covered by 1 mm cartilage and 3.5 +/- 0.2 mm in trabecular bone. The study showed the limitations of LDF in bone and their correlations to various bone properties.

  13. Devices for medical diagnosis with GaN lasers

    Science.gov (United States)

    Kwasny, Miroslaw; Mierczyk, Zygmunt

    2003-10-01

    This paper presents laser-induced fluroescence method (LIF) employing endogenous ("autofluroescence") and exogenous fluorophores. LIF is applied for clinical diagnosis in dermatology, gynaecology, urology, lung tumors as well as for early dentin caries. We describe the analysers with He-Ne, He-Cd, and SHG Nd:YAG lasers and new generation systems based on blue semiconductor GaN lasers that have been implemented into clinical practice till now. The LIF method, fundamental one for many medical applications, with excitation radiation of wavelength 400 nm could be appl,ied only using tunable dye lasers or titanium lasers adequte for laboratory investigations. Development of GaN laser shows possibility to design portable, compact diagnostic devices as multi-channel analysers of fluorescence spectra and surface imaging devoted to clinical application. The designed systems used for spectra measurement and registration of fluorescence images include lasers of power 5-30 mW and generate wavelengths of 405-407 nm. They are widely used in PDT method for investigation of superficial distribution of accumulation kinetics of all known photosensitizers, their elimination, and degradation as well as for treatment of superficial lesions of mucosa and skin. Excitation of exogenous porphrins in Soret band makes possible to estimate their concentration and a period of healthy skin photosensitivity that occurs after photosensitiser injections. Due to high sensitivity of spectrum analysers, properties of photosensitisers can be investigated in vitro (e.g. their aggregation, purity, chromatographic distributions) when their concentrations are 2-3 times lower in comparison to concentrations investigated with typical spectrofluorescence methods. Dentistry diagnosis is a new field in which GaN laser devices can be applied. After induction with blue light, decreased autofluorescence intensity can be observed when dentin caries occur and strong characteristic bands of endogenous porphyrines

  14. Evaluating the effect of low-level laser therapy on healing of tentomized Achilles tendon in streptozotocin-induced diabetic rats by light microscopical and gene expression examinations.

    Science.gov (United States)

    Aliodoust, Morteza; Bayat, Mohammad; Jalili, Mohammad Reza; Sharifian, Zainalabedin; Dadpay, Masoomeh; Akbari, Mohammad; Bayat, Mehrnoush; Khoshvaghti, Amir; Bayat, Homa

    2014-07-01

    Tendon healing is impaired in individuals diagnosed with diabetes mellitus (DM). According to research, there is considerable improvement in the healing of surgically tenotomized Achilles tendons following low-level laser therapy (LLLT) in non-diabetic, healthy animals. This study uses light microscopic (LM) and semi-quantitative reverse transcription PCR (RT-PCR) analyses to evaluate the ability of LLLT in healing Achilles tendons from streptozotocin-induced diabetic (STZ-D) rats. A total of 88 rats were randomly divided into two groups, non-diabetic and diabetic. DM was induced in the rats by injections of STZ. The right Achilles tendons of all rats were tenotomized 1 month after administration of STZ. Laser-treated rats were treated with a helium-neon (He-Ne) laser that had a 632.8-nm wavelength and 7.2-mW average power. Experimental group rats received a daily dose of 0.014 J (energy density, 2.9 J/cm(2)). Control rats did not receive LLLT. Animals were sacrificed on days 5, 10, and 15 post-operatively for semi-quantitative LM and semi-quantitative RT-PCR examinations of transforming growth factor-beta1 (TGF-β1) gene expression. The chi-square test showed that LLLT significantly reduced inflammation in non-diabetic rats compared with their non-diabetic controls (p = 0.02). LLLT significantly decreased inflammation in diabetic rats on days 5 (p = 0.03) and 10 (p = 0.02) compared to the corresponding control diabetic rats. According to the student's t test, LLLT significantly increased TGF-β1 gene expression in healthy (p = 0.000) and diabetic (p = 0.000) rats compared to their relevant controls. The He-Ne laser was effective in altering the inflammatory reaction and increasing TGF-β1 gene production.

  15. Quantification of telomere length by FISH and laser scanning cytometry

    Science.gov (United States)

    Mahoney, John E.; Sahin, Ergun; Jaskelioff, Mariela; Chin, Lynda; DePinho, Ronald A.; Protopopov, Alexei I.

    2008-02-01

    Telomeres play a critical role in the maintenance of chromosomal stability. Telomere erosion, coupled with loss of DNA damage checkpoint function, results in genomic instability that promotes the development of cancer. The critical role of telomere dynamics in cancer has motivated the development of technologies designed to monitor telomere reserves in a highly quantitative and high-throughput manner in humans and model organisms. To this end, we have adapted and modified two established technologies, telomere-FISH and laser scanning cytometry. Specifically, we have produced a number of enhancements to the iCys LSC (CompuCyte) package including software updates, use of 60X dry objectives, and increased spatial resolution by 0.2 um size of stage steps. In addition, the 633 nm HeNe laser was replaced with a 532 nm green diode laser to better match the viewing options. Utilization of telomere-deficient mouse cells with short dysfunctional telomeres and matched telomerase reconstituted cultures demonstrated significantly higher mean integral specific fluorescence values for mTR transfectants relative to empty vector controls: 4.485M vs. 1.362M (ptelomere intensities for individual cells were obtained and demonstrated intercellular heterogeneity in telomere lengths. The validation of the approach derives from a strong correlation between iCys LSC values and Southern blotting. This validated method greatly increases our experimental throughput and objectivity.

  16. Hematite and Goethite (U-Th)/He/Ne ages interpretation using crystallographic data and diffusion parameters

    Science.gov (United States)

    Gautheron, Cécile; Balout, Hilal; Roques, Jérôme; Allard, Thierry; Morin, Guillaume; Tassan-Got, Laurent

    2016-04-01

    At the Earth's surface, hematite and goethite are common minerals occurring in soils and sediments, including ores. The understanding of the corresponding alteration and weathering processes relies on our ability to perform the dating of formation of these minerals. Two relevant and recent dating methods have been developed, which are related to (U-Th)/He and (U-Th)/Ne geochronometers. They are based on accumulation of 4He and 21Ne associated with the alpha decay of U and Th. Both methods are of particular interest because of possible He and Ne retention over geological ages at surface temperature. However, because of different atomic radius between He and Ne, retention behavior of these two species can be quite different. Moreover, the dating procedure is particularly challenging because of the small crystals size and frequent polycrystalline structure of hematite and goethite. As a matter of fact, some uncertainty exists about He and Ne diffusion parameters, due to the nanometric to micrometric crystal size of natural iron oxide mineral. Accordingly, the determination of (U-Th)/He and (U-Th)/Ne ages requires the understanding of He and Ne production and retention (which may be partial) in iron oxide crystals. In this study, we theoretically investigate and discuss for the first time the age evolution for pure goethite and hematite crystals with different thermal histories, including reheating to simulate burial. The aim is to quantify the He and/or Ne loss by ejection and diffusion for crystals of different morphology and polycrystalline structures. This will allow one to provide some correction factor for the age. For this purpose, we used new He and Ne diffusion coefficients obtained by multi-scale theoretical approach using Density Functional Theory (DFT) (Balout et al., submitted, a,b), associated with 3D production and diffusion code (Gautheron and Tassan-Got, 2010). The impact of Multi Diffusion Domains simulating polycrystalline structure has been incorporated in this code in order to reproduce realistic crystallographic structure. Balout, H., Roques, J., Gautheron, C., Tassan-Got, L., Mbongo-Djimbi, D., submitted a. Helium diffusion in pure hematite (α-Fe2O3) for thermochronometric applications: a theoretical multi-scale study. Balout, H., Roques, J., Gautheron, C., Tassan-Got, L., submitted b. Computational investigation of the interstitial neon diffusion in pure hematite, α-Fe2O3. Gautheron, C., Tassan-Got, L., 2010. A Monte Carlo approach of diffusion applied to noble gas/helium thermochronology. Chemical Geology, 273: 212-224.

  17. Interatomic Coulombic Decay of HeNe dimers after ionization and excitation of He and Ne

    Science.gov (United States)

    Sann, H.; Havermeier, T.; Kim, H.-K.; Sturm, F.; Trinter, F.; Waitz, M.; Zeller, S.; Ulrich, B.; Meckel, M.; Voss, S.; Bauer, T.; Schneider, D.; Schmidt-Böcking, H.; Wallauer, R.; Schöffler, M.; Williams, J. B.; Dörner, R.; Jahnke, T.

    2017-01-01

    We study the decay of a helium/neon dimer after ionization and simultaneous excitation of either the neon or the helium atom using Cold Target Recoil Ion Momentum Spectroscopy (COLTRIMS). We find that, depending on the decaying state, either direct Interatomic Coulombic Decay (ICD) (i.e. mediated by a virtual photon exchange), exchange ICD (mediated by electron exchange) or radiative charge transfer occurs. The corresponding channels are identified.

  18. Fungicidal response of a novel natural photosensitizer (Beta vulgaris) on Candida albicans with low-power laser radiation

    Science.gov (United States)

    Mittal, Subhangi; Roy, Sukhdev; Srivastava, J. N.

    2013-05-01

    We report the efficacy of an aqueous extract of Beta vulgaris as a novel, natural photosensitizer for use in photodynamic therapy against Candidiasis disease. This study evaluates the effect of different laser wavelengths (He-Ne: 633 nm, Nd-YAG: 532 nm), power (17, 27 mW) and duration of exposure (5, 10, 15 min) in combination with the Beta vulgaris natural photosensitizer on the viability of Candida albicans causing Candidiasis disease. Although inhibition was observed in all cases, a maximum of 51.91% inhibition takes place with the combination of Beta vulgaris exposed to 532 nm at 27 mW for 15 min by the Agar well diffusion method. The study is important in optimizing different parameters and designing a low-power, compact, non-invasive and portable device for treatment.

  19. Intraoperative clinical use of low-power laser irradiation following surgical treatment of the tethered spinal cord

    Science.gov (United States)

    Rochkind, S.; Alon, M.; Ouaknine, G. E.; Weiss, S.; Avram, J.; Razon, Nisim; Lubart, Rachel; Friedmann, Harry

    1991-05-01

    Based on previous experimental investigations which indicated that low-power laser irradiation has a significant therapeutic effect and treatment potential on the injured nerve tissue, the authors began using this method in clinical practice. This data represents the first clinical results in the treatment of four patients with tethered spinal cord resulting from fibrous adhesions at the site of previous myelomeningocele and lypomyelomeningocele repair, thickened filum terminale and spinal lipoma. After surgical release of the tethered spinal cord, stable evoked responses were recorded and the conus medullaris was subjected to direct laser irradiation (CW He-Ne laser, 632.8nm, 7Jcm2). The findings show intraoperative laser treatment increases evoked responses from 15-52% (mean 26.7%). In a previous work, it was shown that direct laser irradiation promotes restoration of the electrophysiological activity of the severely injured peripheral nerve, prevents degenerative changes in neurons of the spinal cord and induces proliferation of astrocytes and oligodendrocytes. This suggested a higher metabolism in neurons and improved ability for myelin production under the influence of laser treatment. It is well known that tethering of the spinal cord causes mechanical damage to neuronal cell membranes leading to metabolic disturbances in the neurons. For this reason, the authors believe that using low-power laser irradiation may improve neuronal metabolism, prevent neuronal degeneration and promote improved spinal cord function and repair.

  20. Os efeitos do laser hélio-neônio de baixa intensidade na cicatrização de lesões cutâneas induzidas em ratos Effects of low-level helium-neon laser on induced wound healing in rats

    Directory of Open Access Journals (Sweden)

    Viviane L. Busnardo

    2010-02-01

    Full Text Available OBJETIVO: Avaliar os efeitos do laser de baixa potência hélio e neônio (HeNe na cicatrização de feridas cutâneas de ratos. MÉTODOS: Sessenta ratos Wistar foram divididos em grupos controle e experimento. Utilizou-se ferida incisional, longitudinal, dorso-mediana, suturada com pontos separados simples. No grupo experimento, as feridas foram irradiadas diariamente com aparelho de laser de HeNe com potência contínua máxima de 5mW, comprimento de onda de 632,8 nm, visível com densidade de energia de 4J/cm², área de raio do laser de 0,015cm², durante 36 segundos, em três pontos da lesão. As feridas foram avaliadas no 3º, no 7º e no 14º dia de pós-operatório. Cortes histológicos foram corados com hematoxilina-eosina (H&E e avaliados segundo protocolo de Vizzotto et al. (2003* para identificar o tipo de reação inflamatória e com Picrosirius para identificar os colágenos I e III e o índice de maturidade da cicatriz (IMaC. Utilizou-se imunoistoquímica com anti-CD45-LCA para o reconhecimento das células inflamatórias. RESULTADOS: Ambos os grupos mostraram o mesmo padrão inflamatório. No grupo experimento, observaram-se menos células inflamatórias nos três tempos estudados (pOBJECTIVE: To evaluate the effects of low-level helium-neon (HeNe laser on cutaneous wound healing in rats. METHODS: Sixty Wistar rats were divided into control group and experimental group. A sutured longitudinal, dorsal-medial incision was made, with simple separate stitches. The experimental group was irradiated daily in three areas of the wound with HeNe laser (5mW maximum continuous power, 632.8 nm wavelength, 4 J/cm² energy density and 0.015 cm² laser beam area for 36 seconds. The areas were evaluated on the third, seventh and fourteenth days postoperative. Histological sections were stained with hematoxylin-eosin to determine the type of inflammatory reaction according to the protocol by Vizzotto et al. (2003* and with Picrosirius to identify

  1. Nd:YAG laser-induced hyperthermia treatment of spontaneously occurring veterinary head and neck tumors.

    Science.gov (United States)

    Panjehpour, M; Overholt, B F; Frazier, D L; Klebanow, E R

    1991-01-01

    Conventional hyperthermia treatment of superficial tumors in the oral cavity is troublesome due to difficulty in accessing the lesion. A new hyperthermia technique employing near-infrared radiation delivered through a flexible silica optical fiber is described. The system consisted of an Nd:YAG laser for tissue heating, a He-Ne laser for aiming beam, a computer-controlled optical shutter, an interstitial thermometer, computer, and a printer. A 3-m-long 600-microns silica fiber delivered laser energy to the tumor via surface illumination. Using the aiming beam, the spot size was adjusted to include 5 mm of surrounding normal tissue. A thermocouple implanted in the tumor base provided temperature feedback to maintain desired hyperthermic temperature within the lesion. Three spontaneously occurring canine (two squamous cell carcinomas on the gum, one pigmented melanoma on the hard palate) and one feline tumor (squamous cell carcinoma on the nose) have been treated with Nd:YAG laser hyperthermia. Hyperthermia was delivered at 43.5 degrees C for 1 h. All animals received standard radiation treatment prior to hyperthermia. Nd:YAG laser hyperthermia allowed effective and efficient delivery of heat to veterinary nasal and oral lesions otherwise not treatable with conventional heating techniques.

  2. Influence of Helium-Neon Laser Photostimulation on Excision Wound Healing in Wistar Rats

    Directory of Open Access Journals (Sweden)

    B. S. Nayak

    2007-01-01

    Full Text Available The importance of laser photostimulation is now accepted generally but the laser light facilitates wound healing and tissue repair remains poorly understood. So we have examined the hypothesis that the laser photo stimulation can enhances the collagen production in excision wounds using excision wound model in Wister rat model. The circular wounds were created on the dorsum of the back of the animals. The animals were divided into two groups. The experimental group (n = 12 wound was treated with 632.8 nm He-Ne laser at a dose of 2.1J cm-2 for five days a week until the complete healing. The control group was sham irradiated. The parameters studied were wound area, period of epithelization and hydroxyproline. Significant increase in the hydroxyproline content (p<0.001 and reduction in the wound size (p<0.001 was observed in study group when compared to controls. The significant epithelization (p<0.001 was noticed. The experimental wounds were, on average, fully healed by the 15th day, whereas the control group healed, on average by 22nd day. Wound contraction together with the hydroxyproline and experimental observations suggested that low intensity Helium-Neon laser photo stimulation facilitates the tissue repair process by accelerating collagen production in chronic wounds.

  3. Low-cost scheme for high-precision dual-wavelength laser metrology.

    Science.gov (United States)

    Kok, Yitping; Ireland, Michael J; Robertson, J Gordon; Tuthill, Peter G; Warrington, Benjamin A; Tango, William J

    2013-04-20

    A method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dual-wavelength metrology, which employs heterodyne detection, the method developed in this work utilizes direct detection of interference fringes of two He-Ne lasers as well as a less precise stepper motor open-loop position control system to perform its measurement. Although the method may be applicable to a variety of circumstances, the specific application in which this metrology is essential is in an astrometric optical long baseline stellar interferometer dedicated to precise measurement of stellar positions. In our example application of this metrology to a narrow-angle astrometric interferometer, measurement of nanometer precision could be achieved without frequency-stabilized lasers, although the use of such lasers would extend the range of optical path length the metrology can accurately measure. Implementation of the method requires very little additional optics or electronics, thus minimizing the cost and effort of implementation. Furthermore, the optical path traversed by the metrology lasers is identical to that of the starlight or science beams, even down to using the same photodetectors, thereby minimizing the noncommon path between metrology and science channels.

  4. Helium-neon laser irradiation enhances DNA synthesis in a human neuroblastoma cell line

    Science.gov (United States)

    Condon, Michael R.; Gump, Frank; Wu, Wen-hsien

    1993-07-01

    To gain further insight into the mechanism of cell photostimulation by laser light ((lambda) equals 632.8 nm), DNA synthesis was measured in the human neuroblastoma cell line BE(2)-C. Cells were irradiated at high density to establish the characteristics of cellular energy into S- phase in response to laser stimulation. BE(2)-C cells after release from a quiescent, growth arrested state exhibited increased incorporation of isotope 12 hours after replating at subconfluent density in the presence of 2.5% fetal bovine serum (FBS) and [3H] thymidine. In contrast, cells replated under the same conditions, but stimulated with 15% FBS exhibited a time lag of approximately 16 hours in apparent DNA synthesis. These results were not corroborated by flow cytometry. Laser irradiation did not affect the fraction of cells entering S-phase. It therefore appears that the stimulatory effect of He-Ne laser irradiation on BE(2)-C cells is to enhance DNA synthesis while not altering the G1-S transition rate.

  5. Comparison of treatment for 153 cases of circumferential facial paralysis by low-power laser and galvan acupuncture

    Science.gov (United States)

    Li, Hai-Ling; Zhuo, Qing-shan

    1993-03-01

    Seventy-six patients were treated by low power He-Ne laser irradiation on Yangbai, Sibai, and other related acupoints. The other 77 cases were treated by Galvan-acupuncture with infrared radiation on the same acupoints. There was little difference between the therapeutic effects of these two groups (P > 0.05). However, the laser group had a much shorter treatment time than the other group. According to the theory of traditional Chinese medicine, circumferential facial paralysis is caused by exposure to cold which blocks the channel of vital energy resulting in the damage of bodily function. Acupuncture and moxibustion on certain acupoints can warm up the channels and remove the stasis allowing vital energy to pass through their passages to regulate bodily functions. Laser can do the same effectively with much less time. The laser therapy also features painlessness, safeness, and is free of bacteria. Circumferential facial paralysis is a common disease, which is clinically treated by acupuncture with reliable results. However, acupuncture is not fit for children who are not cooperative and those patients who are afraid of the pain accompanied with acupuncture. So we applied low power laser irradiation in the treatment of circumferential facial paralysis starting in 1985. The results were favorable. And the treatment time was shortened. The treatment procedures are reported.

  6. The development of laser surgery and medicine in China

    Science.gov (United States)

    Chen, Mingzhe

    2005-07-01

    acne scar, osmidrosis etc. For ophthalmology, excimer laser are used for myopia or hyperopia; argon green laser, krypton yellow laser are adopted in coagulation for retinal detachment and neovascularization etc. Lasers are often used for the canaliculoplasty in the lacrimal canal. Low level lasers had been used very often on the acupuncture points and for many chronic diseases. Intravascular low level laser irradiation adopting semiconductor lasers and He-Ne laser were reported to use for comatose patients, schizophrenia, vascular dementia, Alzeimer"s disease and coronary disease. Reports from laboratory studies in the field of low level laser demonstrated the stimulation effect on the cells and immunology system; inhibitory effect on proliferation; it improved the biomedical data in hemorrheology; promoted the spinal motor nerve cell function, axonal regeneration; increased epidermal Langerhams cell to improve the antigen function, increased myocardial capillary permeability. Intra-coronary low power red laser irradiation assisted coronary interventional therapy showed its prevention effect on restenosis. Studies about the effects of various kinds of lasers, their wavelength, power densities and doses on various kinds of tissues were reported.

  7. Two-photon excitation laser scanning microscopy of porcine nasal septal cartilage following Nd:YAG laser-mediated stress relaxation

    Science.gov (United States)

    Kim, Charlton C.; Wallace, Vincent P.; Rasouli, Alexandre; Coleno, Mariah L.; Dao, Xavier; Tromberg, Bruce J.; Wong, Brian J.

    2000-05-01

    Laser irradiation of hyaline cartilage result in stable shape changes due to temperature dependent stress relaxation. In this study, we determined the structural changes in chondrocytes within porcine nasal septal cartilage tissue over a 4-day period using a two-photon laser scanning microscope (TPM) following Nd:YAG laser irradiation (lambda equals 1.32 micrometer) using parameters that result in mechanical stress relaxation (6.0 W, 5.4 mm spot diameter). TPM excitation (780 nm) result in induction of fluorescence from endogenous agents such as NADH, NADPH, and flavoproteins in the 400 - 500 nm spectral region. During laser irradiation diffuse reflectance (from a probe HeNe laser, (lambda) equals 632.8 nm), surface temperature, and stress relaxation were measured dynamically. Each specimen received one, two, or three sequential laser exposures (average irradiation times of 5, 6, and 8 seconds). The cartilage reached a peak surface temperature of about 70 degrees Celsius during irradiation. Cartilage denatured in 50% EtOH (20 minutes) was used as a positive control. TPM was performed using a mode-locked 780 nm Titanium:Sapphire (Ti:Al203) beam with a, 63X, 1.2 N.A. water immersion objective (working distance of 200 mm) to detect the fluorescence emission from the chondrocytes. Images of chondrocytes were obtained at depths up to 150 microns (lateral resolution equals 35 micrometer X 35 micrometer). Images were obtained immediately following laser exposure, and also after 4 days in culture. In both cases, the irradiated and non-irradiated specimens do not show any discernible difference in general shape or auto fluorescence. In contrast, positive controls (immersed in 50% ethanol), show markedly increased fluorescence relative to both the native and irradiated specimens, in the cytoplasmic region.

  8. Clinical, radiographic, and histopathologic evaluation of Nd:YAG laser pulpotomy on human primary teeth.

    Science.gov (United States)

    Odabaş, Mesut Enes; Bodur, Haluk; Bariş, Emre; Demir, Cem

    2007-04-01

    The purpose of this study was to compare clinical, radiographic, and histopathologic effects of Nd:YAG laser pulpotomy to formocresol pulpotomy on human primary teeth. Patients with at least two vital primary molar teeth that required pulpotomy, because of pulpal exposure to caries, were selected for this study. After hemorrhage control, complete hemostasis into the canal orifice was achieved by exposure to Nd:YAG laser (1064 nm) and an He-Ne laser (the aiming beam of the Nd:YAG laser) in noncontact mode at 2 W, 20 Hz, 100 mJ, or was achieved by applying 1:5 dilution of formocresol. Forty-two teeth in two groups were to be followed up clinically and radiographic at 1, 3, 6, 9, and 12 months. Eighteen teeth planned for serial extractions were selected for histopathologic study. The teeth were extracted at 7 and 60 days. The teeth in the laser group had a clinical success rate of 85.71% and a radiographic success rate 71.42% at 12 months. The teeth in the formocresol group had a clinical and radiographic success rate of 90.47% at 12 months. There were no statistically significant differences between laser and formocresol group with regard to both clinical and radiographic success rates. There was a statistically significant difference between 7- and 60-day laser groups with regard to inflammatory cell response criteria. Dentin bridge was absent in all samples. No stained bacteria were observed in any of these samples. In conclusion, Nd:YAG laser may be considered as an alternative to formocresol for pulpotomies in primary teeth.

  9. Laser Therapy of Irradiated Traumatized Skeletal Muscles and State of Immune System in Animals

    Directory of Open Access Journals (Sweden)

    Nelly Bulyakova

    2011-01-01

    Full Text Available Problems statement: This study was designed to examine the effect of laser therapy on regeneration of traumatized skeletal muscles and on dynamics of immune responses in thymus and bone marrow under ionizing radiation. Approach: After local X-ray radiation of both rat gastrocnemius muscles at a dose 20 Gy or after total γ-irradiation of animals at a semiletal dose 6 Gy, the muscles were damaged considerably as contractile organ (full cut across muscle. Then laser therapy was carried out with a helium-neon laser (632.8 nm or infrared pulsed laser (890 nm, 10 treatments by 3 min during the first 15 or 30 days after trauma.The investigations were performed using histological, biochemical, cytological, cytogenetic and morphometric methods. Results: The received data showed that under ionizing radiation, He-Ne and IR laser irradiation stimulated the regeneration of skeletal muscles, improved the healing of skin-muscle wound and stimulated the prosesses of postradiation recovery in cells of the thymus and bone marrow. The regenerative activity of radiated traumatized muscles and the level of reduction of cytogenetic damages in bone marrow and the thymus varied depending on the period for which regenerative muscles were exposured to laser light, as well as the optical characteristics of lasers and the degree of radiation damages. The early appearance of reactive changes in structure of the thymus and the display them during 60 days point to increasing function of organ. Conclusion: Under local and total ionizing radiation and laser therapy of solely damaged skeletal muscles, positive dynamics of regeneration processes and improvement of cytological and cytogenetic indexes for main immune organs (the thymus and bone marrow were observed. Herewith, the functional loading on thymus increased. We suggest that the findings should be considered in clinical practice.

  10. Nanosecond pulsed laser ablation of Ge investigated by employing photoacoustic deflection technique and SEM analysis

    Science.gov (United States)

    Yaseen, Nazish; Bashir, Shazia; Shabbir, Muhammad Kaif; Jalil, Sohail Abdul; Akram, Mahreen; Hayat, Asma; Mahmood, Khaliq; Haq, Faizan-ul; Ahmad, Riaz; Hussain, Tousif

    2016-06-01

    Nanosecond pulsed laser ablation phenomena of single crystal Ge (100) has been investigated by employing photoacoustic deflection as well as SEM analysis techniques. Nd: YAG laser (1064 nm, 10 ns, 1-10 Hz) at various laser fluences ranging from 0.2 to 11 J cm-2 is employed as pump beam to ablate Ge targets. In order to evaluate in-situe ablation threshold fluence of Ge by photoacoustic deflection technique, Continuous Wave (CW) He-Ne laser (632 nm, power 10 mW) is employed as a probe beam. It travels parallel to the target surface at a distance of 3 mm and after passing through Ge plasma it causes deflection due to density gradient of acoustic waves. The deflected signal is detected by photodiode and is recorded by oscilloscope. The threshold fluence of Ge, the velocity of ablated species and the amplitude of the deflected signal are evaluated. The threshold fluence of Ge comes out to be 0.5 J cm-2 and is comparable with the analytical value. In order to compare the estimated value of threshold with ex-situe measurements, the quantitative analysis of laser irradiated Ge is performed by using SEM analysis. For this purpose Ge is exposed to single and multiple shots of 5, 10, 50 and 100 at various laser fluences ranging from 0.2 to 11 J cm-2. The threshold fluence for single and multiple shots as well as incubation coefficients are evaluated. It is observed that the value of incubation co-efficient decreases with increasing number of pulses and is therefore responsible for lowering the threshold fluence of Ge. SEM analysis also reveals the growth of various features such as porous structures, non-uniform ripples and blisters on the laser irradiated Ge. It is observed that both the fluence as well as number of laser shots plays a significant role for the growth of these structures.

  11. Pulsed laser deposition of silicon dioxide thin films with silicone targets for fabricating waveguide devices

    Science.gov (United States)

    Okoshi, Masayuki; Kuramatsu, Masaaki; Inoue, Narumi

    2002-06-01

    Silicon dioxide (SiO2) thin films were deposited at room temperature by 193-nm ArF excimer laser ablation of silicone in oxygen atmosphere. Only the side chains of the target were photo-dissociated during ablation to deposit Si-O bonds on a substrate in high laser fluence at about 10 J/cm2. Oxygen gas worked to oxidize the Si-O bonds ejected from the target to from SiO2 thin films at the gas pressure of 4.4 X 10-2 Torr, in addition to reducing the isolated carbon mixed into the films. We also found that the deposited rate could control refractive index of the films. The refractive index of the film deposited at 0.05 nm/pulse is greater than that of the film at 0.1 nm/pulse. Thus, a 0.2-micrometers thick SiO2 cladding film deposited at 0.1 nm/pulse was firstly formed on the whole surface of a 100- micrometers -thick polyester film, and then a 0.6 micrometers -thick SiO2 core film at 0.05 nm/pulse was fabricated in a line on the sample. The sample functioned as a waveguide device for a 633-nm line of He-Ne laser.

  12. Laser Raman Spectroscopy with Different Excitation Sources and Extension to Surface Enhanced Raman Spectroscopy

    Directory of Open Access Journals (Sweden)

    Md. Wahadoszamen

    2015-01-01

    Full Text Available A dispersive Raman spectrometer was used with three different excitation sources (Argon-ion, He-Ne, and Diode lasers operating at 514.5 nm, 633 nm, and 782 nm, resp.. The system was employed to a variety of Raman active compounds. Many of the compounds exhibit very strong fluorescence while being excited with a laser emitting at UV-VIS region, hereby imposing severe limitation to the detection efficiency of the particular Raman system. The Raman system with variable excitation laser sources provided us with a desired flexibility toward the suppression of unwanted fluorescence signal. With this Raman system, we could detect and specify the different vibrational modes of various hazardous organic compounds and some typical dyes (both fluorescent and nonfluorescent. We then compared those results with the ones reported in literature and found the deviation within the range of ±2 cm−1, which indicates reasonable accuracy and usability of the Raman system. Then, the surface enhancement technique of Raman spectrum was employed to the present system. To this end, we used chemically prepared colloidal suspension of silver nanoparticles as substrate and Rhodamine 6G as probe. We could observe significant enhancement of Raman signal from Rhodamine 6G using the colloidal solution of silver nanoparticles the average magnitude of which is estimated to be 103.

  13. A laser scanner for imaging fluorophore labeled molecules in electrophoretic gels

    Energy Technology Data Exchange (ETDEWEB)

    Fisk, D.J.; Sutherland, J.C. [Brookhaven National Lab., Upton, NY (United States). Biology Dept.

    1995-08-01

    A laser scanner for imaging electrophoretic gels was constructed and tested. The scanner incorporates a green helium-neon (HeNe) laser (543.5nm wavelength) and can achieve a spatial resolution of 19{micro}m. The instrument can function in two modes : snap-shot and finish-line. In snapshot mode, all samples are electrophoresed for the same time and the gel is scanned after completion of electrophoresis, while in finish-line mode, fluorophore labeled samples are electrophoresed for a constant distance and the image is formed as the samples pass under the detector. The resolving power of the finish-line mode of imaging is found to be greater than that of the snapshot mode of imaging. This laser scanner is also compared with a Charge Coupled Device (CCD) camera and in terms of resolving power is found to be superior. Sensitivity of the instrument is presented in terms of the minimum amount of DNA that can be detected verses its molecular length.

  14. A 1.82 m^2 ring laser gyroscope for nano-rotational motion sensing

    CERN Document Server

    Belfi, Jacopo; Bosi, Filippo; Carelli, Giorgio; Di Virgilio, Angela; Maccioni, Enrico; Ortolan, Antonello; Stefani, Fabio

    2011-01-01

    We present a fully active-controlled He-Ne ring laser gyroscope, operating in square cavity 1.35 m in side. The apparatus is designed to provide a very low mechanical and thermal drift of the ring cavity geometry and is conceived to be operative in two different orientations of the laser plane, in order to detect rotations around the vertical or the horizontal direction. Since June 2010 the system is active inside the Virgo interferometer central area with the aim of performing high sensitivity measurements of environmental rotational noise. So far, continuous not attempted operation of the gyroscope has been longer than 30 days. The main characteristics of the laser, the active remote-controlled stabilization systems and the data acquisition techniques are presented. An off-line data processing, supported by a simple model of the sensor, is shown to improve the effective long term stability. A rotational sensitivity at the level of ten nanoradiants per squareroot of Hz below 1 Hz, very close to the required ...

  15. Real time confocal laser scanning microscopy: Potential applications in space medicine and cell biology

    Science.gov (United States)

    Rollan, Ana; Ward, Thelma; McHale, Anthony P.

    Photodynamic therapy (PDT), in which tissues may be rendered fatally light-sensitive represents a relatively novel treatment for cancer and other disorders such as cardiovascular disease. It offers significant application to disease control in an isolated environment such as space flight. In studying PDT in the laboratory, low energy lasers such as HeNe lasers are used to activate the photosensitized cellular target. A major problem associated with these studies is that events occurring during actual exposure of the target cells to the system cannot be examined in real time. In this study HeLa cells were photosensitized and photodynamic activation was accomplished using the scanning microbeam from a confocal laser scanning microscope. This form of activation allowed for simultaneous photoactivation and observation and facilitated the recording of events at a microscopic level during photoactivation. Effects of photodynamic activation on the target cells were monitored using the fluorophores rhodamine 123 and ethidium homodimer-1. Potential applications of these forms of analyses to space medicine and cell biology are discussed.

  16. Light attenuation in rat skin following low level laser therapy on burn healing process

    Science.gov (United States)

    Teixeira Silva, Daniela Fátima; Simões Ribeiro, Martha

    2010-04-01

    Low-level laser therapy (LLLT) is commonly used to accelerate wound healing. Besides, the technique of imaging the light distribution inside biological tissues permits us to understand several effects about light-tissue interaction. The purpose of this study was to determine the relative attenuation coefficient of the light intensity in healthy and burned skin rats during cutaneous repair following LLLT or not. Two burns about 6mm in diameter were cryogenerated using liquid N2 on the back of 15 rats. Lesion L was irradiated by a He-Ne laser (λ= 632.8nm) and fluence 1.0J/cm2; Lesion C was control and received sham irradiation. A healthy skin area (H) was also analyzed. The lesions were irradiated at days 3, 7, 10 and 14 post-burning. The animals were euthanized at days 3, 10 and 31 and skin samples were carefully removed and placed between two microscope slides, spaced by z= 1mm. A laser beam irradiated the sandwiched tissue from epidermis to dermis. A CCD camera was placed orthogonal to the beam path and it photographed the distribution of the scattered light. The light decay occurred according to the Beer's Law. Significance was accepted at p exponential. Burned skin samples presented decay significantly faster than healthy skin samples. Besides, attenuation coefficient changed during burning healing comparing treated and control lesions. These findings suggest that the relative attenuation coefficient is a suitable parameter to optimize LLLT during wound healing.

  17. Low-level laser therapy on MCF-7 cells: a micro-Fourier transform infrared spectroscopy study

    Science.gov (United States)

    Magrini, Taciana D.; dos Santos, Nathalia Villa; Milazzotto, Marcella Pecora; Cerchiaro, Giselle; da Silva Martinho, Herculano

    2012-10-01

    Low-level laser therapy (LLLT) is an emerging therapeutic approach for several clinical conditions. The clinical effects induced by LLLT presumably scale from photobiostimulation/photobioinhibition at the cellular level to the molecular level. The detailed mechanism underlying this effect remains unknown. This study quantifies some relevant aspects of LLLT related to molecular and cellular variations. Malignant breast cells (MCF-7) were exposed to spatially filtered light from a He-Ne laser (633 nm) with fluences of 5, 28.8, and 1000 mJ/cm2. The cell viability was evaluated by optical microscopy using the Trypan Blue viability test. The micro-Fourier transform infrared technique was employed to obtain the vibrational spectra of each experimental group (control and irradiated) and identify the relevant biochemical alterations that occurred due to the process. It was observed that the red light influenced the RNA, phosphate, and serine/threonine/tyrosine bands. We found that light can influence cell metabolism depending on the laser fluence. For 5 mJ/cm2, MCF-7 cells suffer bioinhibition with decreased metabolic rates. In contrast, for the 1 J/cm2 laser fluence, cells present biostimulation accompanied by a metabolic rate elevation. Surprisingly, at the intermediate fluence, 28.8 mJ/cm2, the metabolic rate is increased despite the absence of proliferative results. The data were interpreted within the retrograde signaling pathway mechanism activated with light irradiation.

  18. A real-time, nonintrusive trace gas detector based on laser photothermal deflection

    Science.gov (United States)

    de Vries, H. S. M.; Dam, N.; van Lieshout, M. R.; Sikkens, C.; Harren, F. J. M.; Reuss, J.

    1995-09-01

    We present the layout and technical details of a trace gas monitor based on photothermal deflection. The operating principle of this instrument, i.e., the deflection of a (weak) probe laser beam by the thermal refractive index gradient induced by trace gas absorption of an intense pump laser beam, allows nonintrusive measurements with good space and time resolution. An intra-cavity CO2 laser is used as the pump beam and a red HeNe laser as the probe. The latter runs perpendicular to the pump beam to optimize spatial resolution. To increase sensitivity, the probe laser is incorporated in a multipass setup. The instrument is demonstrated by the localization of ethylene emission sites on a cherry tomato and by monitoring ammonia production due to nitrogen fixation by cyanobacteria. Both C2H4 and NH3 can be detected at the 1-3 ppb level, at a spatial resolution of 2 mm (along the pump laser)×0.6 mm (perpendicular to it), and a response time of 0.1 s (without background correction) or 15 s (including background correction). Sensitivity can be increased at the expense of spatial resolution, and vice versa. In principle, this instrument is applicable to all those gases possessing a characteristic (``fingerprint'') spectrum in the CO2 laser range. The great advantage of the photothermal deflection technique with respect to other trace gas detection schemes lies in the nonintrusive character of the measurements. There is no need to enclose the sample in a vessel or to suck large volumes of air into the detector; measurements can be performed in open air and in real time. This should prove especially useful where sticky (polar) gases, like H2O, NH3, CH3OH, etc., are to be detected quantitatively. Main applications include air quality monitoring, especially concerning dry deposition rate measurements using the eddy correlation technique, and the study of volatile metabolite emission of biological samples.

  19. Clinical effectiveness of low-level laser treatment on peripheral somatosensory neuropathy.

    Science.gov (United States)

    Fallah, Alireza; Mirzaei, Alireza; Gutknecht, Norbert; Demneh, Amir Saberi

    2017-04-01

    Peripheral sensory neuropathy treatment is one of the common treatment problems and causes morbidity and mortality in people suffering from that. Although treatment depends on the underlying cause of the condition, nevertheless, in some cases, there is no cure for it, and it requires palliative and symptomatic treatment. In laboratory studies, low-level laser has been effective in the nerves protection and restoration. The aim of this article is to investigate the clinical efficacy of low-level laser on improvement of the peripheral somatosensory neuropathy. Search in the articles published up to 30 October 2015 (full text and abstracts) in databases PubMed (Medline), Cochrane library, Physiotherapy Evidence Database was performed. The studies of low-level laser trials on patients with peripheral neuropathy were carried out and evaluated in terms of the exclusion criteria. There are 35 articles among which 10 articles had the intended and required criteria. 1, 3, and 6 articles study the patients with diabetes, neuropathy caused by trauma, and carpal tunnel syndrome, respectively. In six studies, laser led to a reduction in sensory impairment and improvement of the physiological function of the sensory nerves. In these articles, lasers (Diode, GaAlAs, He-Ne) had wavelength range 660-860 nm, radiation power 20-250 mW, energy density 0.45-70 J/cm(2). The intervention sessions range was 6-21 times and patient follow-up was 0-6 months. According to the results of these studies, low-level laser therapy can improve sensory function in patients with peripheral somatosensory neuropathy, although little research have not been done, laser treatment regimens are varied and do not recommend a specific treatment protocol. It seems it requires more research to sum up better, particularly in relation to diabetes.

  20. Photo-stimulatory effect of low energy helium-neon laser irradiation on excisional diabetic wound healing dynamics in wistar rats

    Directory of Open Access Journals (Sweden)

    Maiya Arun

    2009-01-01

    Full Text Available Background: Generally, the significances of laser photo stimulation are now accepted, but the laser light facilitates wound healing and tissue repair remains poorly understood. Aims: We have examined the hypothesis that the laser photo stimulation can enhance the collagen production in diabetic wounds using the excision wound model in the Wistar rat model. Methods: The circular wounds were created on the dorsum of the back of the animals. The animals were divided into two groups. The study group (N = 24 wound was treated with 632.8 nm He-Ne laser at a dose of 3-9J/cm 2 for 5 days a week until the wounds healed completely. The control group was sham irradiated. Result: A significant increase in the hydroxyproline content and reduction in the wound size were observed in the study group. The pro-healing actions seem to be due to increased collagen deposition as well as better alignment and maturation. Conclusion: The biochemical analysis and clinical observation suggested that 3-6 J/cm 2 laser photo stimulation facilitates the tissue repair process by accelerating collagen production in diabetic wound healing.

  1. Experimental investigation of two-frequency up-conversion in ZBLAN: Pr,Yb%ZBLAN:Pr,Yb中双频上转换实验研究

    Institute of Scientific and Technical Information of China (English)

    刘名扬

    2012-01-01

    This paper reports an investigation for the two frequency up-conversion luminescence of Pr3+ ion. In the experiment, Pr3+, Yb3+ :ZBLAN glass is chosen as the frequency up-conversion fluorescence material. The relation between up-conversion fluorescence intensity and ion doped concentration is analyzed. The experimental conditions to realize the clear two frequency up-conversion 3-D display are therefore obtained.%本文对Pr3+离子双频上转换发光进行了研究.实验中选用Pr3+和Yb3+:ZBLAN玻璃作为频率上转换发光材料;分析了上转换发光强度和离子掺杂浓度的关系,得出了实现较清晰双频上转换三维立体图像的实验条件.

  2. KrF laser deposition of chromium films from Cr(CO)[sub 6]: in situ detection of film growth by laser transmission experiments

    Energy Technology Data Exchange (ETDEWEB)

    Konstantinov, L. (Inst. of Applied Mineralogy, Bulgarian Academy of Sciences, Sofia (Bulgaria)); Nowak, R.; Hess, P. (Inst. of Physical Chemistry, Heidelberg Univ. (Germany))

    1992-10-15

    The results of a detailed study of laser-induced chemical vapour deposition (LICVD) of thin chromium films from Cr(CO)[sub 6] using a KrF excimer laser are presented. The following deposition parameters were varied: the laser fluence, the pulse repetition rate, the total gas pressure in the deposition cell, the flow rate of the gas mixture supply, the type of carrier or buffer gas and the substrate temperature. The influence of these parameters on the nucleation time and rate, and the main film growth rate as well as on film properties such as the optical absorption coefficient was investigated. The film growth kinetics was monitored in situ by measuring the transmission of an HeNe laser probe beam through the deposit. The experimental results are discussed in the framework of a model of pulsed LICVD based on gas phase diffusion mass transport to the substrate surface of chromium-containing precursor species as the rate-limiting step. The model describes the experimental data reasonably well, the deviations observed being indicative of processes not included in the model such as reactions at the film surface. The results indicate that in pulsed LICVD of chromium films from Cr(CO)[sub 6] at 248 nm the main precursors of the film growth during the nucleation period are chromium atoms and other highly reactive unsaturated chromium carbonyls formed on illumination in the gas phase, while during the main growth stage the role of more stable saturated species adsorbed on the surface between the laser pulses may be dominant.

  3. Laser Micromachining and Information Discovery Using a Dual Beam Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Theppakuttaikomaraswamy, Senthil P. [Iowa State Univ., Ames, IA (United States)

    2001-01-01

    Lasers have proven to be among the most promising tools for micromachining because they can process features down to the size of the laser wavelength (smaller than 1 micrometer) and they provide a non-contact technology for machining. The demand for incorporating in-situ diagnostics technology into the micromachining environment is driven by the increasing need for producing micro-parts of high quality and accuracy. Laser interferometry can be used as an on-line monitoring tool and it is the aim of this work to enhance the understanding and application of Michelson interferometry principle for the in-situ diagnostics of the machining depth on the sub-micron and micron scales. micromachining is done on two different materials and a comprehensive investigation is done to control the width and depth of the machined feature. To control the width of the feature, laser micromachining is done on copper and a detailed analysis is performed. The objective of this experiment is to make a precision mask for sputtering with an array of holes on it using an Nd:YAG laser of 532 nm wavelength. The diameter of the hole is 50 μm and the spacing between holes (the distance between the centers) is 100 μm. Michelson interferometer is integrated with a laser machining system to control the depth of machining. An excimer laser of 308 nm wavelength is used for micromachining. A He-Ne laser of 632.8 nm wavelength is used as the light source for the interferometer. Interference patterns are created due to the change in the path length between the two interferometer arms. The machined depth information is obtained from the interference patterns on an oscilloscope detected by a photodiode. To compare the predicted depth by the interferometer with the true machining depth, a surface profilometer is used to measure the actual machining depth on the silicon. It is observed that the depths of machining obtained by the surface profile measurement are in accordance with the interferometer

  4. Laser Micromachining and Information Discovery Using a Dual Beam Interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Senthil P. Theppakuttaikomaraswamy

    2001-12-31

    Lasers have proven to be among the most promising tools for micromachining because they can process features down to the size of the laser wavelength (smaller than 1 micrometer) and they provide a non-contact technology for machining. The demand for incorporating in-situ diagnostics technology into the micromachining environment is driven by the increasing need for producing micro-parts of high quality and accuracy. Laser interferometry can be used as an on-line monitoring tool and it is the aim of this work to enhance the understanding and application of Michelson interferometry principle for the in-situ diagnostics of the machining depth on the sub-micron and micron scales. micromachining is done on two different materials and a comprehensive investigation is done to control the width and depth of the machined feature. To control the width of the feature, laser micromachining is done on copper and a detailed analysis is performed. The objective of this experiment is to make a precision mask for sputtering with an array of holes on it using an Nd:YAG laser of 532 nm wavelength. The diameter of the hole is 50 {micro}m and the spacing between holes (the distance between the centers) is 100 {micro}m. Michelson interferometer is integrated with a laser machining system to control the depth of machining. An excimer laser of 308 nm wavelength is used for micromachining. A He-Ne laser of 632.8 nm wavelength is used as the light source for the interferometer. Interference patterns are created due to the change in the path length between the two interferometer arms. The machined depth information is obtained from the interference patterns on an oscilloscope detected by a photodiode. To compare the predicted depth by the interferometer with the true machining depth, a surface profilometer is used to measure the actual machining depth on the silicon. It is observed that the depths of machining obtained by the surface profile measurement are in accordance with the

  5. Development of high resolution Michelson interferometer for stable phase-locked ultrashort pulse pair generation.

    Science.gov (United States)

    Okada, Takumi; Komori, Kazuhiro; Goshima, Keishiro; Yamauchi, Shohgo; Morohashi, Isao; Sugaya, Takeyoshi; Ogura, Mutsuo; Tsurumachi, Noriaki

    2008-10-01

    We developed a high resolution Michelson interferometer with a two-frequency He-Ne laser positioning system in order to stabilize the relative phase of a pulse pair. The control resolution corresponded to a 12 as time resolution or a phase of 1.5 degrees at 900 nm. This high resolution Michelson interferometer can generate a phase-locked pulse pair either with a specific relative phase such as 0 or pi radians or with an arbitrary phase. Coherent control of an InAs self-assembled quantum dot was demonstrated using the high resolution Michelson interferometer with a microspectroscopy system.

  6. Effect of Caffeic Acid and Low-Power Laser Light Co-Exposure on Viability of Pseudomonas aeruginosa

    Directory of Open Access Journals (Sweden)

    Gheibi

    2015-08-01

    Full Text Available Background The resistance of Pseudomonas aeruginosa to antibiotics is a big problem, especially in burns and wound infections. Laser irradiation affects microorganisms by denaturing their proteins, which involves changes in the chemical or physical properties of the protein. Objectives The aim of this study was to investigate the effect of caffeic acid and low-power laser light co-exposure on Pseudomonas aeruginosa isolated from burn wounds. Materials and Methods Ten bacterial samples were collected from patients with burn wound infections at Shahid Motahhari medical center of Tehran. The He-Ne laser was used in this study with output power of 2 mW. Results The data significantly indicated that both the caffeic acid and laser treatment alone reduced the number of colony-forming units compared to control cultures. Co-exposure of bacterial suspensions to caffeic acid and laser at three time points showed the following number of colony-forming units 240.23 ± 60.15, 148.13 ± 52.66 and 84.57 ± 35, respectively. The best concentrations of caffeic acid to achieve countable colonies were 1.5 and 1.75 mM. At the concentration of 1.5 mM of caffeic acid, the number of colonies significantly reduced to 280.78 ± 59 (P = 0.008 while at 1.75 mM the number of colonies reduced to 234.07 ± 72.28 (P = 0.0001. Conclusions Caffeic acid treatment reduced bacterial growth and resulted in a decreased number of colony formation. The simultaneous effect of caffeic acid and laser at three time courses showed a synergic effect in reducing colony formation compared to the control and caffeic acid, and laser alone.

  7. Laser Materials and Laser Spectroscopy - A Satellite Meeting of IQEC '88

    Science.gov (United States)

    Wang, Zhijiang; Zhang, Zhiming

    1989-03-01

    Langmuir-Blodgett Monolayer by Surface Enhanced Raman Scattering * Dynamics of Laser-induced Etching of Si(III) Surface of Chlorine * Fourier Transform Heterodyne Spectroscopy of Liquid Interfaces * Generation of High Power UV Femtosecond Pulses * Femtosecond Photon Echoes * Transition Radiation of Femtosecond Optical Pulses * Observation of DFWN in a Saturable Absorber inside the CPM Ring Dye Laser Cavity * Study on the Induced Spectral Superbroadening of Ultrafast Laser Pulse in a Nonlinear Medium * Laser Cooling and Trapping of Atoms * Femtosecond Absorption Spectroscopy of Primary Processes in Bacterial Photosynthesis Reaction Centers * Observation of the Motion of Slow Atoms in a Standing Wave Field * The Interrelation between the Optical Properties and the MBE Growth Control of Quantum Well Structures * Ionic Excimers * Optical SHG Study on Polymerization of Langmuir-Blodgett Molecular Layers * Weak Localization of Light * Statistical Fragmentation Patterns of Metastable Ion: Comparison with Experiment * Oxygeneration Reaction of Cerium with XeCl Laser * Measurement of Verdet Coefficient and Magneto-optic Spectroscopy in terms of Beats * Study on Rhodamine 6G/Xylene and Red B Laser Dye Mixture System * Ultranarrow Absorption Resonances of Cold Particles and their Application in Spectroscopy and Optical Frequency Standards * The Dynamics of Ion Clouds in Paul Traps: Implications for Frequency Standard Applications * Frequency Stability Measurement of Zeeman Stabilized He-Ne Laser * Multi-wavelength CW He-Ne Laser and its Frequency Stabilization * Efficient Isotope Separation using Semiconductor Lasers * Multi-beam Circularly Polarized Holography * Ring Laser Opticity Meter * Improved Rademacher Functions and Rademacher Transform * Note

  8. Directional spectra of ocean waves from microwave backscatter: A physical optics solution with application to the short-pulse and two-frequency measurement techniques

    Science.gov (United States)

    Jackson, F. C.

    1979-01-01

    Two simple microwave radar techniques that are potentially capable of providing routine satellite measurements of the directional spectrum of ocean waves were developed. One technique, the short pulse technique, makes use of very short pulses to resolve ocean surface wave contrast features in the range direction; the other technique, the two frequency correlation technique makes use of coherency in the transmitted waveform to detect the large ocean wave contrast modulation as a beat or mixing frequency in the power backscattered at two closely separated microwave frequencies. A frequency domain analysis of the short pulse and two frequency systems shows that the two measurement systems are essentially duals; they each operate on the generalized (three frequency) fourth-order statistical moment of the surface transfer function in different, but symmetrical ways, and they both measure the same directional contrast modulation spectrum. A three dimensional physical optics solution for the fourth-order moment was obtained for backscatter in the near vertical, specular regime, assuming Gaussian surface statistics.

  9. Experimental Study of Effect of Low Power Laser on Telomere Length of Cells%低功率激光对细胞端粒DNA长度影响的实验研究

    Institute of Scientific and Technical Information of China (English)

    黄玲; 吴智辉; 莫华

    2013-01-01

    To investigate the effect of low power helium neon laser (He-Ne laser) on the telomere length of human fetal lung diploid fibroblast (2BS) cell,we used the laser (λ=632.8nm,P=2mW) to treat the young 2BS cells.Cell growth and proliferation was observed through MTT method after treating with low power laser.The relative telomere length of 2BS cells was detected by fluorescence real-time quantitative PCR (q-PCR).The results showed that the cells of the treated groups grew better than the untreated groups.The telomere DNA length of the old 2BS cells,treated by low power He-Ne laser when they were young,was longer than that of untreated group.The results of the present study indicated that the low power He-Ne laser might decrease shortening rate of telomere and delay the aging of cells.Therefore,this study provides the experimental basis for us to further investigate the effect of low power laser on cell aging at the gene level.%本研究目的是探讨低功率氦氖激光对人胚肺二倍体成纤维(2BS)细胞端粒DNA长度的影响.低功率氦氖激光(波长632.8 nm,功率2 mW可调)对年轻2BS细胞进行照射处理,采用四甲基偶氮唑盐微量酶反应比色法(MTT)检测细胞生长和增殖的变化,采用实时荧光定量聚合酶链式反应(q-PCR)方法检测细胞端粒DNA相对长度.结果表明,激光照射组细胞生长趋势均优于非激光照射组(P<0.05);2BS细胞在年轻时经激光照射后传代至老年时的端粒长度较对照组的老年细胞端粒长度长(P<0.05).研究结果提示,经适当激光照射后,细胞端粒DNA因衰老而变短的趋势得到减缓.本研究从基因水平为探讨低功率激光延缓细胞衰老的激光生物效应提供实验依据.

  10. Separation and quantitation of phycobiliproteins using phytic acid in capillary electrophoresis with laser-induced fluorescence detection.

    Science.gov (United States)

    Viskari, Pertti J; Colyer, Christa L

    2002-10-01

    The similar electrophoretic mobilities and sizes of several of the phycobiliproteins, which are derived from the photosynthetic apparatus of cyanobacteria and eukaryotic algae, render their separation and quantitation a challenging problem. However, we have developed a suitable capillary electrophoresis (CE) method that employs a phytic acid-boric acid buffer and laser-induced fluorescence (LIF) detection with a single 594 nm He-Ne laser. This method takes advantage of the remarkably high quantum yields of these naturally fluorescent proteins, which can be attributed to their linear tetrapyrrole chromophores covalently bound to cysteinyl residues. As such, limits of detection of 1.18 x 10(-14), 5.26 x 10(-15), and 2.38 x 10(-15) mol/l were obtained for R-phycoerythrin, C-phycocyanin, and allophycocyanin proteins, respectively, with a linear dynamic range of eight orders of magnitude in each case. Unlike previously published CE-LIF methods, this work describes the separation of all three major classes of phycobiliproteins in under 5 min. Very good recoveries, ranging from 93.2 to 105.5%, were obtained for a standard mixture of the phycobiliproteins, based on seven-point calibration curves for both peak height and peak area. It is believed that this development will prove useful for the determination of phycobiliprotein content in naturally occurring cyanobacteria populations, thus providing a useful tool for understanding biological and chemical oceanographic processes.

  11. Vibrational spectroscopy characterization of low level laser therapy on mammary culture cells: a micro-FTIR study

    Science.gov (United States)

    Magrini, Taciana D.; Villa dos Santos, Nathalia; Pecora Milazzotto, Marcella; Cerchiaro, Giselle; da Silva Martinho, Herculano

    2011-03-01

    Low level laser therapy (LLLT) is an emerging therapeutic approach for several clinical conditions. The clinical effects induced by LLLT presumably go from the photobiostimulation/photobioinibition at cellular level to the molecular level. The detailed mechanism underlying this effect is still obscure. This work is dedicated to quantify some relevant aspects of LLLT related to molecular and cellular variations. This goal was attached by exposing malignant breast cells (MCF7) to spatially filtered light of a He-Ne laser (633 nm) with 28.8 mJ/cm2 of fluency. The cell viability was evaluated by microscopic observation using Trypan Blue viability test. The vibrational spectra of each experimental group (micro- FTIR technique) were used to identify the relevant biochemical alterations occurred due the process. The red light had influence over RNA, phosphate and serine/threonine/tyrosine bands. Light effects on cell number or viability were not detected. However, the irradiation had direct influence on metabolic activity of cells.

  12. Effect of Low Power Laser Irradiation on the Ability of Cell Growth and Myogenic Differentiation of Myoblasts Cultured In Vitro

    Directory of Open Access Journals (Sweden)

    Cui-Ping Zhang

    2014-01-01

    Full Text Available As a therapeutic modality, low power laser irradiation (LPLI has been used clinically in the treatment of skeletal muscle injuries and other myopathic conditions, but the cellular and molecular mechanisms attributed to this therapy were still unclear. Myoblasts are a type of myogenic stem cells quiescence in mature skeletal muscle fibers and are considered as the source cells during the regenerating process. The purpose of this paper was to investigate the effects of LPLI on the proliferation and myogenic differentiation of the cultured myoblasts and to find out the major candidates responsible for LPLI-induced muscle regeneration in vivo. In this study, primary rat myoblasts were exposed to helium-neon (He-Ne laser. Cell proliferation, differentiation, and the cellular responses to LPLI were monitored by using morphological observation and molecular biological methods. It was found that LPLI at a certain fluence could increase the cell growth potential for myoblasts and further induce more cells entering into S phase of the mitotic cycle as indicated by high levels of bromodeoxyuridine (BrdU incorporation, while at the same time inhibiting their in vitro differentiation and decreasing the expression of myogenic regulatory genes to a certain extent. Taken together, these results provide experimental evidence for the clinical applications of LPLI in regenerating skeletal muscle.

  13. Development and evaluation of fiber optic probe-based helium-neon low-level laser therapy system for tissue regeneration--an in vivo experimental study.

    Science.gov (United States)

    Prabhu, Vijendra; Rao, Satish B S; Rao, Nageshwara B; Aithal, Kiran B; Kumar, Pramod; Mahato, Krishna K

    2010-01-01

    We report the design and development of an optical fiber probe-based Helium-Neon (He-Ne) low-level laser therapy system for tissue regeneration. Full thickness excision wounds on Swiss albino mice of diameter 15 mm were exposed to various laser doses of 1, 2, 3, 4, 6, 8 and 10 J cm(-2) of the system with appropriate controls, and 2 J cm(-2) showing optimum healing was selected. The treatment schedule for applying the selected laser dose was also standardized by irradiating the wounds at different postwounding times (0, 24 and 48 h). The tissue regeneration potential was evaluated by monitoring the progression of wound contraction and mean wound healing time along with the hydroxyproline and glucosamine estimation on wound ground tissues. The wounds exposed to 2 J cm(-2) immediately after wounding showed considerable contraction on days 5, 9, 12, 14, 16 and 19 of postirradiation compared with the controls and other treatment schedules, showing significant (P < 0.001) decrease in the healing time. A significant increase in hydroxyproline and glucosamine levels was observed for the 2 J cm(-2) irradiation group compared with the controls and other treatment groups. In conclusion, the wounds treated with 2 J cm(-2) immediately after the wounding show better healing compared with the controls.

  14. Biphotonic holographic gratings in azobenzene polyesters: Surface relief phenomena and polarization effects

    DEFF Research Database (Denmark)

    Sánchez, C.; Alcalá, R.; Hvilsted, Søren

    2000-01-01

    Biphotonic holographic gratings have been recorded in a side-chain azobenzene liquid crystalline polyester using a blue incoherent source and a He-Ne laser. Intensity gratings and the appearance of surface relief have been observed when two linearly polarized beams from a He-Ne laser are made...

  15. Multi-image acquisition-based distance sensor using agile laser spot beam.

    Science.gov (United States)

    Riza, Nabeel A; Amin, M Junaid

    2014-09-01

    We present a novel laser-based distance measurement technique that uses multiple-image-based spatial processing to enable distance measurements. Compared with the first-generation distance sensor using spatial processing, the modified sensor is no longer hindered by the classic Rayleigh axial resolution limit for the propagating laser beam at its minimum beam waist location. The proposed high-resolution distance sensor design uses an electronically controlled variable focus lens (ECVFL) in combination with an optical imaging device, such as a charged-coupled device (CCD), to produce and capture different laser spot size images on a target with these beam spot sizes different from the minimal spot size possible at this target distance. By exploiting the unique relationship of the target located spot sizes with the varying ECVFL focal length for each target distance, the proposed distance sensor can compute the target distance with a distance measurement resolution better than the axial resolution via the Rayleigh resolution criterion. Using a 30 mW 633 nm He-Ne laser coupled with an electromagnetically actuated liquid ECVFL, along with a 20 cm focal length bias lens, and using five spot images captured per target position by a CCD-based Nikon camera, a proof-of-concept proposed distance sensor is successfully implemented in the laboratory over target ranges from 10 to 100 cm with a demonstrated sub-cm axial resolution, which is better than the axial Rayleigh resolution limit at these target distances. Applications for the proposed potentially cost-effective distance sensor are diverse and include industrial inspection and measurement and 3D object shape mapping and imaging.

  16. Evaluation of Laser Stabilization and Imaging Systems for LCLS-II - Final Paper

    Energy Technology Data Exchange (ETDEWEB)

    Barry, Matthew [Auburn Univ., AL (United States)

    2015-08-20

    By combining the top performing commercial laser beam stabilization system with the most ideal optical imaging configuration, the beamline for the Linear Accelerator Coherent Light Source II (LCLS-II) will deliver the highest quality and most stable beam to the cathode. To determine the optimal combination, LCLS-II beamline conditions were replicated and the systems tested with a He-Ne laser. The Guidestar-II and MRC active laser beam stabilization systems were evaluated for their ideal positioning and stability. Both a two and four lens optical imaging configuration was then evaluated for beam imaging quality, magnification properties, and natural stability. In their best performances when tested over fifteen hours, Guidestar-II kept the beam stable over approximately 70-110um while the MRC system kept it stable over approximately 90-100um. During short periods of time, Guidestar-II kept the beam stable between 10-20um, but was more susceptible to drift over time, while the MRC system maintained the beam between 30-50um with less overall drift. The best optical imaging configuration proved to be a four lens system that images to the iris located in the cathode room and from there, imaged to the cathode. The magnification from the iris to the cathode was 2:1, within an acceptable tolerance to the expected 2.1:1 magnification. The two lens configuration was slightly more stable in small periods of time (less than 10 minutes) without the assistance of a stability system, approximately 55um compared to approximately 70um, but the four lens configurations beam image had a significantly flatter intensity distribution compared to the two lens configuration which had a Gaussian distribution. A final test still needs to be run with both stability systems running at the same time through the four lens system. With this data, the optimal laser beam stabilization system can be determined for the beamline of LCLS-II.

  17. Low-power pulsed Nd:YAG laser irradiation for pre-emptive anaesthesia: A morphological and histological study.

    Science.gov (United States)

    Chan, Ambrose; Punnia-Moorthy, Arumugam; Armati, Patricia

    2014-12-27

    To determine if tooth structure or dental pulp of normal healthy human premolar teeth to be extracted for orthodontic reasons exhibit morphological or histological changes following dental anaesthesia by pulsed Nd:YAG laser and subsequent cavity preparation (CP). Materials (Subjects) and Methods: 54 bilateral paired of human, healthy premolar teeth identified for inclusion in a clinical trial of Nd:YAG-induced anaesthesia and subsequently extracted for orthodontic reasons, were randomly divided into 4 treatment groups: Group 1 - teeth (n=44) were irradiated with 150 µs pulsed Nd:YAG laser-1064 nm (American Dental Laser, dLase300, Sunrise Technologies Inc., Folsom, CA, USA; Average power: 1.1 ± 0.2 W, power density: 39+ 0.7 W/cm(2), area 0.28 cm(2), 15 Hz; energy density:0. 260+ 0.047 J/cm(2)) +Sham EMLA (cream without active component) followed by cavity preparation (CP); Group 2 - Teeth (n=44) - were treated with EMLA + Sham Laser (1 mW 632.8-nm He:Ne laser aiming beam only) with CP; Group 3 Teeth (n=10) - were irradiated with pulsed Nd:YAG laser as above but minus CP; Group 4 (n=10)- was a Control group with teeth untreated (no Laser, EMLA or CP). Clinical anaesthesia was assessed by electric pulp testing (EPT) and CP. Teeth in each of the 4 groups were processed for examination by i) scanning electron microscopy (SEM); ii) longitudinal undecalcified ground sectioning (LUGS); iii) light microscopy of pulpal tissues or iv) dye penetration. Both Laser and EMLA groups demonstrated no alteration to mineralized tooth structure and dentinal permeability. Mild superficial pulpal changes were found in both groups (3/18 teeth) and of no statistical difference (p>0.99, the McNemar test). Neither Laser nor the Control groups minus CP, showed pulpal changes. Low-power pulsed Nd:YAG laser dose, as used in the clinical trial to induce anaesthesia, does not cause morphological damage to the mineralized tooth structure. Both Laser and EMLA groups showed minor superficial

  18. Low level laser therapy with trigger points technique: a clinical study on 243 patients.

    Science.gov (United States)

    Simunovic, Z

    1996-08-01

    Among the various methods of application techniques in low level laser therapy (LLLT) (HeNe 632.8 nm visible red or infrared 820-830 nm continuous wave and 904 nm pulsed emission) there are very promising "trigger points" (TPs), i.e., myofascial zones of particular sensibility and of highest projection of focal pain points, due to ischemic conditions. The effect of LLLT and the results obtained after clinical treatment of more than 200 patients (headaches and facial pain, skeletomuscular ailments, myogenic neck pain, shoulder and arm pain, epicondylitis humery, tenosynovitis, low back and radicular pain, Achilles tendinitis) to whom the "trigger points" were applied were better than we had ever expected. According to clinical parameters, it has been observed that the rigidity decreases, the mobility is restored (functional recovery), and the spontaneous or induced pain decreases or even disappears, by movement, too. LLLT improves local microcirculation and it can also improve oxygen supply to hypoxic cells in the TP areas and at the same time it can remove the collected waste products. The normalization of the microcirculation, obtained due to laser applications, interrupts the "circulus vitiosus" of the origin of the pain and its development (Melzak: muscular tension > pain > increased tension > increased pain, etc.). Results measured according to VAS/VRS/PTM: in acute pain, diminished more than 70%; in chronic pain more than 60%. Clinical effectiveness (success or failure) depends on the correctly applied energy dose--over/underdosage produces opposite, negative effects on cellular metabolism. We did not observe any negative effects on the human body and the use of analgesic drugs could be reduced or completely excluded. LLLT suggests that the laser beam can be used as monotherapy or as a supplementary treatment to other therapeutic procedures for pain treatment.

  19. Investigations of the potential functions of weakly bound diatomic molecules and laser-assisted excitive Penning ionization

    Energy Technology Data Exchange (ETDEWEB)

    Goble, J.H. Jr.

    1982-05-01

    Three variations on the Dunham series expansion function of the potential of a diatomic molecule are compared. The differences among these expansions lie in the choice of the expansion variable, lambda. The functional form of these variables are lambda/sub s/ = l-r/sub e//r for the Simon-Parr-Finlan version, lambda/sub T/ - 1-(r/sub e//r)/sup p/ for that of Thakkar, and lambda/sub H/ = 1-exp(-rho(r/r/sub e/-1) for that of Huffaker. A wide selection of molecular systems are examined. It is found that, for potentials in excess of thirty kcal/mole, the Huffaker expansion provides the best description of the three, extrapolating at large internuclear separation to a value within 10% of the true dissociation energy. For potentials that result from the interaction of excited states, all series expansions show poor behavior away from the equilibrium internuclear separation of the molecule. The series representation of the potentials of weakly bound molecules are examined in more detail. The ground states of BeAr/sup +/, HeNe/sup +/, NaAr, and Ar/sub 2/ and the excited states of HeNe+, NaNe, and NaAr are best described by the Thakkar expansion. Finally, the observation of laser-assisted excitive Penning ionization in a flowing afterglow is reported. The reaction Ar(/sup 3/P/sub 2/) + Ca + h nu ..-->.. Ar + Ca/sup +/(5p /sup 2/P/sub J/) + e/sup -/ occurs when the photon energy, h nu, is approximately equal to the energy difference between the metastable argon and one of the fine structure levels of the ion's doublet. By monitoring the cascade fluorescence of the above reaction and comparing it to the flourescence from the field-free process Ar(/sup 3/P/sub 2/) + Ca ..-->.. Ar + Ca/sup +/(4p /sup 2/P/sub J/) + e/sup -/ a surprisingly large cross section of 6.7 x 10/sup 3/ A/sup 2/ is estimated.

  20. Fast capillary electrophoresis-laser induced fluorescence analysis of ligase chain reaction products: human mitochondrial DNA point mutations causing Leber's hereditary optic neuropathy.

    Science.gov (United States)

    Muth, J; Williams, P M; Williams, S J; Brown, M D; Wallace, D C; Karger, B L

    1996-12-01

    High speed capillary electrophoresis-laser-induced fluorescence (CE-LIF) has been used to separate and detect point mutations using the ligase chain reaction (LCR). The method utilizes short capillary columns (7.5 cm effective length) and fields of 400 V/cm to analyze DNA-ethidium bromide complexes using an He/Ne laser. The method was first demonstrated with a commercially available kit for LCR based on a lacI gene fragment inserted in a Bluescript II phagemid. LCR-CE-LIF was then applied to detect point mutations in human mitochondrial DNA, resulting in Leber's hereditary optic neuropathy (LHON). Three severe mutations were analyzed in which the original base is substituted by a thymidine base at positions 3460, 11778 and 14459. Appropriate primers were designed with polyT tails for length discrimination of pooled samples. Successful detection of mutated samples was achieved, with appropriate correction for small amounts of nonspecific ligated product. The method is rapid, easy to implement, and automatable.

  1. Two-frequency heating technique at the 18 GHz electron cyclotron resonance ion source of the National Institute of Radiological Sciences

    CERN Document Server

    Biri, S; Muramatsu, M; Drentje, A G; Rácz, R; Yano, K; Kato, Y; Sasaki, N; Takasugi, W

    2015-01-01

    The two-frequency heating technique was studied to increase the beam intensities of highly charged ions provided by the high-voltage extraction configuration (HEC) ion source at the National Institute of Radiological Sciences (NIRS). The observed dependences on microwave power and frequency suggested that this technique improved plasma stability but it required precise frequency tuning and more microwave power than was available before 2013. Recently, a new, high-power (1200 W) wide bandwidth (17.1-18.5 GHz) travelling-wave-tube amplifier (TWTA) was installed. After some single tests with klystron and TWT amplifiers the simultaneous injection of the two microwaves has been successfully realized. The dependence of highly charged ions (HCI) currents on the superposed microwave power was studied by changing only the output power of one of the two amplifiers, alternatively. While operating the klystron on its fixed 18.0 GHz, the frequency of the TWTA was swept within its full limits (17.1-18.5 GHz), and the effec...

  2. You can achieve anything with a laser: ingenuity in the design of the impossible

    Science.gov (United States)

    Davies, Ray

    2009-06-01

    In the area of Photonics Research as to what can be achieved with Low Power Photonics Sources, such as a Class 2 HeNe Laser, a Laser Diode, or an ultra high intensity LED, the Photonics Academy at OpTIC possesses a highly impressive array of functional Prototype Designs. Each of these visually attractive Prototype Designs illustrates the Ingenuity in Design that has been achieved by students, in the range of 15 - 25 years of age, who have been engaged in personal opportunities to Investigate the potential application of Photonics concepts to, and within, a whole range of highly Innovative outcomes, that are clear demonstrations of many students' individual Originality and Ingenuity in creating new ideas for the application of Low Power Photonics Concepts. This Paper will highlight some of the highly Perceptive Prototype Design achievements of students in the application of Photonics principles, with these applications ranging from the Use of a Laser to identify the Letters of a Word in an ordinary book before translating them into Braille for a Visually Handicapped person, to the transmission of audio information over a distance; from a Book Page turning device for a paralysed person, to a pair of Laser Activated Mobile Feet; from a Mobile Guide Robot for a Blind person, to a five-Laser beam Combination Lock for a high Security application; from a Laser Birefringent Seismograph, to a Laser Speckle Activated Robotic Hand; and many, many more. All of the many functioning Prototype Design ideas that will be demonstrated have one characteristic that is common, namely, they are all designed with the intention to help improve the day-to-day experiences of other people, especially those who are impaired in some way. One of the most interesting challenges that can be presented to students is to apply Low Power Laser Photonics to help any visually impaired person within a whole range of activities, and several of the Prototype Designs will illustrate that particular type of

  3. Detailed in situ laser calibration of the infrared imaging video bolometer for the JT-60U tokamak

    Science.gov (United States)

    Parchamy, H.; Peterson, B. J.; Konoshima, S.; Hayashi, H.; Seo, D. C.; Ashikawa, N.; JT-60U Team

    2006-10-01

    The infrared imaging video bolometer (IRVB) in JT-60U includes a single graphite-coated gold foil with an effective area of 9 × 7 cm 2 and a thickness of 2.5 μ m . The thermal images of the foil resulting from the plasma radiation are provided by an IR camera. The calibration technique of the IRVB gives confidence in the absolute levels of the measured values of the plasma radiation. The in situ calibration is carried out in order to obtain local foil properties such as the thermal diffusivity κ and the product of the thermal conductivity k and the thickness t f of the foil. These quantities are necessary for solving the two-dimensional heat diffusion equation of the foil which is used in the experiments. These parameters are determined by comparing the measured temperature profiles (for k t f ) and their decays (for κ ) with the corresponding results of a finite element model using the measured HeNe laser power profile as a known radiation power source. The infrared camera (Indigo/Omega) is calibrated by fitting the temperature rise of a heated plate to the resulting camera data using the Stefan-Boltzmann law.

  4. Lasers technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2011-07-01

    The Lasers Technology Program of IPEN is committed to the development of new lasers based on the research of optical materials and new technologies, as well to laser applications in several areas: Nuclear, Medicine, Dentistry, Industry, Environment and Advanced Research. The Program is basically divided into two main areas: Material and Laser Development and Laser Applications.

  5. Erythrocyte aggregation under high pressure studied by laser photometry and mathematical analysis.

    Science.gov (United States)

    Toyama, Yoshiharu; Yoshida, Hisashi; Yamamoto, Takao; Dobashi, Toshiaki

    2016-04-01

    The effects of hydrostatic pressure on erythrocyte aggregation have been studied by laser photometry and analysis based on a phenomenological theory. Samples were prepared by suspending swine erythrocytes in their own plasma. A high-pressure vessel consisting of a stainless-steel block with a hole to hold a sample cell and two sapphire windows to allows the passage of a He-Ne laser beam was used in the experimental setup. The suspension was stirred at 1500 rpm to disperse the erythrocytes homogeneously. Immediately after reducing the stirring rate from 1500 rpm to 300 rpm, the transmitted light intensity (I) was recorded every 10 ms under a high pressure of 40-200 MPa. The value of I increased with time (t) owing to erythrocyte aggregation. From the phenomenological theory, the equation ΔI(t)=ΔIeq[1-e(-Kt)/(1-B(1-e(-Kt)))] was derived for the change in the transmitted light intensity (ΔI) due to erythrocyte aggregation, where ΔIeq is the transmitted light intensity in the steady state, K is a time constant and B is a constant that represents the ratio of the number of interaction sites on erythrocyte aggregates at time t to that in the steady state. The observed time courses of ΔI obtained at all pressures could be closely fitted to the theoretical equation. ΔIeq roughly increased with increasing pressure. On the other hand, K and B abruptly decreased above 120 MPa. The growth rate of aggregates decreased above 120 MPa. These results suggest a change in the mechanism of erythrocyte aggregation at approximately 120 MPa. We discuss the physical meaning of the parameters.

  6. Detection of bacterial infection of agave plants by laser-induced fluorescence

    Science.gov (United States)

    Cervantes-Martinez, Jesus; Flores-Hernandez, Ricardo; Rodriguez-Garay, Benjamin; Santacruz-Ruvalcaba, Fernando

    2002-05-01

    Greenhouse-grown plants of Agave tequilana Weber var. azul were inoculated with Erwinia carotovora, the causal agent of stem soft rot. We investigated the laser-induced fluorescence (LIF) of agave plants to determine whether LIF can be used as a noninvasive sensing tool for pathological studies. The LIF technique was also investigated as a means of detecting the effect of the polyamine biosynthesis inhibitor beta-hydroxyethylhydrazine as a bactericide against the pathogenic bacterium Erwinia carotovora. A He-Ne laser at 632.8 nm was used as the excitation source, and in vivo fluorescence emission spectra were recorded in the 660-790-range. Fluorescence maxima were at 690 and 740 nm. The infected plants that were untreated with the bactericide showed a definite increase in fluorescence intensity at both maxima within the first three days after infection. Beginning on the fifth day, a steady decrease in fluorescence intensity was observed, with a greater effect at 740 than at 690 nm. After 30 days there was no fluorescence. The infected plants that had been treated with the bactericide showed no significant change in fluorescence compared with that of the uninfected plants. The ratio of fluorescence intensities was determined to be F 690 nm/F 740 nm for all treatments. These studies indicate that LIF measurements of agave plants may be used for the early detection of certain types of disease and for determining the effect of a bactericide on bacteria. The results also showed that fluorescence intensity ratios can be used as a reliable indicator of the progress of disease.

  7. Blue Laser.

    Science.gov (United States)

    1985-12-01

    HOLLOW CATHODE LASER FABRICATION 13 4. EXPERIENCE WITH THE BLUE LASER 18 4.1 Operational and Processing Experience 18 4.2 Performance Testing 20 5...34 -. - . •. SECTION 3 BLUE HOLLOW CATHODE LASER FABRICATION This section presents an overview of the steps taken in creating a HCL. There is...to the laser assembly. These steps can actually be considered as the final steps in laser fabrication because some of them involve adding various

  8. Thermally stimulated third-order optical nonlinearity in Cd-doped CuO-PVA thin films under cw laser illumination

    Science.gov (United States)

    Tamgadge, Y. S.; Pahurkar, V. G.; Talwatkar, S. S.; Sunatkari, A. L.; Muley, G. G.

    2015-08-01

    We report synthesis, linear and third-order nonlinear optical properties of Cd-doped CuO-PVA nanocomposite thin films. Cd-doped CuO nanoparticles (NPs) were obtained by chemical synthesis method, and spin coating technique was used to obtain thin films in polyvinyl alcohol matrix. X-ray diffraction (XRD) shows formation of crystalline CuO having monoclinic phase with average particle size of 10 nm. Ultraviolet-visible (UV-Vis) spectroscopy attests formation of NPs by witnessing strong blue shift in the excitonic absorption. Absorption wavelength of CuO NPs shifts from 365 to 342 nm for Cd doping of 1-5 wt%. Both XRD and UV-Vis data confirm decrease in particle size with increase in Cd-doping concentration. Thin films have been characterized by Z-scan technique under continuous-wave He-Ne laser, and enhanced values of nonlinear refractive index n 2 and nonlinear absorption coefficient β have been obtained. Enhancements in the nonlinear optical properties have been attributed to the thermal effect due to strong linear absorption coefficient combined with increased thermo-optic coefficient. Contributing mechanisms such as photoacoustic effect, surface states effect and dielectric effect due to dopant and thin film structure have been discussed.

  9. Interventional effect of laser acupoint radiation on the expression of Nissl body and brain-derived neurotrophic factor in newborn rat models with ischemic/hypoxic cerebral injury

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    BACKGROUND:Some researches report that He-Ne laser can activate function of erythrocytes and increase content of blood and oxygen via bio-stimulating effect;therefore,it suspects that laser radiation at Baihui and Dazhui can partially increase blood circulation for oxygen-supplying content of brain and improve functional status of neurons.OBJECTIVE:To verify the effects of laser radiation at Baihui and Dazhui on the expression of Nissl body of brain tissue neurons and brain-derived neurotrophic factor (BDNF) in newborn rats with ischemic/hypoxic cerebral injury.DESIGN:Randomized controlled animal study.SETTING:Department of Neurological Histochemistry,Xianning University.MATERIALS:Forty Wistar rats of 7 - 8 days old,weighing 15 - 20 g and of both genders,were selected from Wuhan Experimental Animal Center.All the rats were randomly divided into sham operation group (n =8),model group (n =16) and radiation group (n =16).The experimental animals were disposed according to ethical criteria.BDNF kit was provided by Wuhan Boster Bioengineering Co.,Ltd.METHODS:The experiment was carried out in the Department of Neurological Histochemistry,Xianning University from April 2005 to October 2006.Rats in the radiation group and model group were performed with ligation of left common carotid artery,recovered at room temperature for 1-6 days,maintained in self-made hypoxic cabin under normal pressure and injected mixture gas (0.05 volume fraction of O2 and 0.92 volume fraction of N2) for 2 hours.In addition,rats in the sham operation group were treated with separation of left common carotid artery but not ligation and hypoxia.Rats in the model group were not given any treatment;while,rats in the radiation group were exposed with He-Ne laser of 63.28 nm in the wave length at Baihui and Dazhui acupoints on the second day after ischemia-hypoxia.The radiation was given for 10 minutes per day and once a day.Ten days were regarded as a course and the rats were exposed for 2 courses in

  10. Lasers technology

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The Laser Technology Program of IPEN is developed by the Center for Lasers and Applications (CLA) and is committed to the development of new lasers based on the research of new optical materials and new resonator technologies. Laser applications and research occur within several areas such as Nuclear, Medicine, Dentistry, Industry, Environment and Advanced Research. Additional goals of the Program are human resource development and innovation, in association with Brazilian Universities and commercial partners.

  11. Lasers (Rev.)

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Hal

    1969-01-01

    A laser is an instrument that produces an enormously intense pencil-thin beam of light. In this booklet we shall learn what there is about the laser that gives it so much promise. We shall investigate what it is, how it works, and the different kinds of lasers there are.

  12. Laser device

    Science.gov (United States)

    Scott, Jill R.; Tremblay, Paul L.

    2007-07-10

    A laser device includes a target position, an optical component separated a distance J from the target position, and a laser energy source separated a distance H from the optical component, distance H being greater than distance J. A laser source manipulation mechanism exhibits a mechanical resolution of positioning the laser source. The mechanical resolution is less than a spatial resolution of laser energy at the target position as directed through the optical component. A vertical and a lateral index that intersect at an origin can be defined for the optical component. The manipulation mechanism can auto align laser aim through the origin during laser source motion. The laser source manipulation mechanism can include a mechanical index. The mechanical index can include a pivot point for laser source lateral motion and a reference point for laser source vertical motion. The target position can be located within an adverse environment including at least one of a high magnetic field, a vacuum system, a high pressure system, and a hazardous zone. The laser source and an electro-mechanical part of the manipulation mechanism can be located outside the adverse environment. The manipulation mechanism can include a Peaucellier linkage.

  13. Laser thruster

    Science.gov (United States)

    Jalufka, N. W.

    1989-01-01

    Laser propulsion can reduce fuel by 57 t to 105 t over chemical propulsion for a 144 t Lunar base, with no significant increase in trip time. Laser propulsion reduces trip time by a factor of 40 to 120 over nuclear electric propulsion and time in radiation belts by a factor of 100 to 1700. Either solar or nuclear driven laser diode arrays could produce multimegawatt beams, typically 3,700 t for a 235 MW laser system. Laser diode arrays have high payoff due to short wavelength (850 nm) and high diode efficiency (70 percent). A dry laser OTV of 8790 kg and 60 percent efficiency can transport a 144 t lunar base. Laser propulsion could carry both personnel and cargo safely to the lunar base.

  14. Láser helio-neón combinado con clorhexidina al 0,2 %.: Efectos clínicos y microbiológicos en el tratamiento de la gingivitis crónica Helium-neon laser combined with 0.2% chlorhexidine: Clinical and microbiological effects in the treatment of chronic gingivitis.

    Directory of Open Access Journals (Sweden)

    Tatiana Peña Ruiz

    2007-09-01

    Full Text Available La gingivitis crónica constituye una de las formas más frecuentes de enfermedad periodontal, caracterizada por la inflamación crónica de la encías, tumefacción, enrojecimiento y sangramiento. Su principal factor de riesgo lo constituye la microbiota del surco gingival, que resulta necesario, pero no suficiente para desencadenarla. Se realizó un ensayo clínico-terapéutico fase II, controlado, aleatorizado y a simple ciegas, para evaluar los efectos clínicos y microbiológicos del tratamiento combinado de la radiación láser helio-neón (He-Ne con la clorhexidina al 0,2 %. Todos los pacientes recibieron tratamiento inicial; al mes de finalizado este, se distribuyeron aleatoriamente en 2 grupos: un grupo estudio que recibió la combinación láser-neón y clorhexidina al 0,2 % y otro grupo control que solo recibió clorhexidina al 0,2 %. Se realizó una evaluación a los 15, 30 y 45 días, con criterios de eficacia clínicos y microbiológicos. Los resultados clínicos fueron satisfactorios en el grupo estudio con predominio de los morfotipos I, caracterizados por cocos gramnegativos y positivos, compatibles con un periodonto sano. Los eventos adversos detectados con esta terapéutica fueron mínimos, todos relacionados con la somnolencia.Chronic gingivitis is one of the most common periodontal diseases that is characterized by chronic inflammation, tumefaction, redness and bleeding. The main risk factor is gingival sulcus microbiota that is essential but not enough to unleash it. A phase II controlled randomized blind clinical/therapeutical assay was conducted to evaluate the clinical and microbiological effects of the combined treatment based on helium-neon laser (He-Ne with 0.2% chlorhexidine. All the patients were initially treated; after a month, they were randomly distributed into two groups, that is, the study group received a helium-neon laser plus 0.2% chlorhexidine combination and the control group was treated with 0

  15. Laser photocoagulation - eye

    Science.gov (United States)

    Laser coagulation; Laser eye surgery; Photocoagulation; Laser photocoagulation - diabetic eye disease; Laser photocoagulation - diabetic retinopathy; Focal photocoagulation; Scatter (or pan retinal) photocoagulation; Proliferative ...

  16. [Comparison of therapeutic effects between plum-blossom needle tapping plus cupping and laser irradiation in the treatment of acute facial palsy patients with concomitant peri-auricular pain].

    Science.gov (United States)

    Zhang, Cui-Yan; Wang, Yan-Xiang

    2011-12-01

    To compare the therapeutic effects of plum-blossom needle therapy with cupping and laser irradiation in the treatment of acute facial paralysis with ipsilateral peri-auricular pain. Sixty outpatients with acute facial paralysis and ipsilateral peri-auricular pain were divided into plum-blossom needle (treatment) group (n = 28) and laser-irradiation (control) group (n = 32). In the acute stage, patients of the treatment group were treated with plum-blossom needle tapping in combination with cupping at Yifeng (TE 17) and Wangu (GB 12), while those of the control group treated with He-Ne laser irradiation over the same two acupoints until the peri-auricular pain disappeared. The treatment was given once daily. Following disappearance of the pain, routine acupuncture treatment of Yifeng (TE 17), Wangu (GB 12), Dicang (ST 4), etc. was given continuously to patients of the two groups, once daily for 20 times. The treatment times for healing ipsilateral peri-auricular pain, and the electromyogram (EMG, compound muscle action potential) of the ipsilateral musculus orbicularis oris were recorded. Scores of the facial nerve function were given to House-Brackmann Facial Nerve Grading System. The treatment times for healing peri-auricular pain in the treatment group and laser irradiation group were 2.9 +/- 1. 0 and 6.0 +/- 2.2 respectively (t = 6.816, P = 0.000). The scores of House-Brackmann scale of the paralyzed side in the treatment group and control group were (3.3 +/- 1.5) points and (3.3 +/- 1.4) points (P > 0.05) before the treatment; (1.8 +/- 1.1) points and (2.5 +/- 1.2) points (P 0.05) during the first two weeks after onset, and (79.2 +/- 11.3)% and (69.8 +/- 17.9)% (P facial and muscular functions in the treatment of acute facial paralysis patients.

  17. Dual-polarization mode-locked Nd:YAG laser.

    Science.gov (United States)

    Thévenin, J; Vallet, M; Brunel, M

    2012-07-15

    A mode-locked solid-state laser containing a birefringent element is shown to emit synchronously two frequency combs associated to the two polarization eigenstates of the cavity. An analytical model predicts the polarization evolution of the pulse train, which is determined by the adjustable intracavity birefringence. Experiments realized with a Nd:YAG laser passively mode locked by a semiconductor saturable absorber mirror are in perfect agreement with the model. Locking between the two combs arises for particular values of their frequency difference, e.g., half the repetition rate, and the pulse train polarization sequence is then governed by the relative overall phase offset of the two combs.

  18. Measurement of large nonlinear refractive index of natural pigment extracted from Hibiscus rosa-sinensis leaves with a low power CW laser and by spatial self-phase modulation technique

    Science.gov (United States)

    Biswas, S.; Kumbhakar, P.

    2017-02-01

    We have reported here, for the first time, to the best of our knowledge, a high nonlinear refractive index (n2e) of a natural pigment extracted from Hibiscus rosa-sinensis leaves by using spatial self-phase modulation technique (SSPM) with a low power CW He-Ne laser radiation at 632.8 nm. It is found by UV-Vis absorption spectroscopic analysis that chlrophyll-a, chlrophyll-b and carotenoid are present in the pigment extract with 56%, 25% and 19%, respectively. The photoluminescence (PL) emission characteristics of the extracted samples have also been measured at room temperature as well as in the temperature range of 283-333 K to investigate the effect of temperature on luminescent properties of the sample. By analyzing the SSPM experimental data, the nonlinear refractive index value of pigment extract has been determined to be 3.5 × 10- 5 cm2/W. The large nonlinear refractive index has been assigned due to asymmetrical structure, molecular reorientation and thermally induced nonlinearity in the sample. The presented results might open new avenues for the green and economical technique of syntheses of organic dyes with such a large nonlinear optical property.

  19. 紫外氦氖诱变选育高产聚苹果酸菌株%Breeding of High Poly (Malic Acid)-Producing Mutation Induced by UV, He and Ne laser

    Institute of Scientific and Technical Information of China (English)

    乔长晟; 郝华旋; 姜少丽; 敖爱华; 王坤

    2011-01-01

    In this study, ninety mutants with acid-producing capabilities were induced from Aureobasidium Pullulans TKPM00006 by UV and He Ne laser. Then they were primarily screened by Bromocresol green and the only carbon source fermentation of succinic acid and citric acid. Through the determination of poly (malic acid)-producing capability, a high poly (malic acid)-producing mutant was obtained. With this strain, PMLA yield reached 12.62g/L> which was 2.97 times than its parent strain. The results showed that the mutant was genetically stable.%以出芽短梗霉(Aureobasidium Pullulans) TKPM00006为出发菌株,用紫外和氦氖激光结合诱变,通过溴甲酚绿变色指示平板和分别以丁二酸、柠檬酸为唯一碳源的摇瓶初筛得到90株产酸明显的菌株,再经过摇床产量测定,复筛得到1株高产聚苹果酸( PMLA)的菌株.其摇瓶产量为12.62 g/L,较原菌聚苹果酸产量提高了2.97倍.经过传代培养,证明遗传性状稳定.

  20. A laser

    Energy Technology Data Exchange (ETDEWEB)

    Togo, N.; Syundzo, Yo.

    1984-06-19

    It is reported that an improved gas laser design using pumping of the active medium has been developed. A diagram of the laser system is given in graph form and its principle of operation is briefly described. A special sealing element is used in such lasers to seal the reservoir containing the oil in the pump which pumps the gas active medium. When the sealing element fails, there is the danger of oil penetration into the active laser medium. It is proposed that an additional pump which continually evacuates the oil reservoir during laser system operation be used. Thus, a low pressure is maintained in the reservoir. If the sealing element fails, the secondary pump generates a gas flow from the pumping system to the reservoir and eliminates gas penetration into the laser medium.

  1. Biocavity Lasers

    Energy Technology Data Exchange (ETDEWEB)

    Gourley, P.L.; Gourley, M.F.

    2000-10-05

    Laser technology has advanced dramatically and is an integral part of today's healthcare delivery system. Lasers are used in the laboratory analysis of human blood samples and serve as surgical tools that kill, burn or cut tissue. Recent semiconductor microtechnology has reduced the size o f a laser to the size of a biological cell or even a virus particle. By integrating these ultra small lasers with biological systems, it is possible to create micro-electrical mechanical systems that may revolutionize health care delivery.

  2. High power lasers & systems

    OpenAIRE

    Chatwin, Chris; Young, Rupert; Birch, Philip

    2015-01-01

    Some laser history;\\ud Airborne Laser Testbed & Chemical Oxygen Iodine Laser (COIL);\\ud Laser modes and beam propagation;\\ud Fibre lasers and applications;\\ud US Navy Laser system – NRL 33kW fibre laser;\\ud Lockheed Martin 30kW fibre laser;\\ud Conclusions

  3. Laser yellowing

    Indian Academy of Sciences (India)

    M B Sai Prasad; Salvatore Siano

    2010-12-01

    Over the past few years there has been an increasing interest in researches related to the application of lasers in conservation, analysis and diagnostics of artwork surfaces. Among the many interesting problems to be tackled, one issue was drawing more interest because of the limitations it can impose on the use of lasers. Laser yellowing is a phenomenon wherein artwork surfaces assume a yellow hue when cleaned with Q-switched Nd:YAG (1064 nm) lasers in particular. Here the effect of yellowing has been studied and quantified for artwork surfaces (marble) using SFR Nd:YAG and LQS Nd:YAG lasers. Colorimetric measurements by employing a spectroradiometer helps to quantify the effect of yellowing by analysing three variables (chromaticity coordinates) of interest.

  4. Ultrahigh-gradient acceleration of injected eletrons by laser-excited relativistic electron plasma waves

    Science.gov (United States)

    Clayton, C. E.; Marsh, K. A.; Dyson, A.; Everett, M.; Lal, A.; Leemans, W. P.; Williams, R.; Joshi, C.

    1993-01-01

    High-gradient acceleration of externally injected 2.1-MeV electrons by a laser beat wave driven relativistic plasma wave has been demonstrated for the first time. Electrons with energies up to the detection limit of 9.1 MeV were detected when such a plasma wave was resonantly excited using a two-frequency laser. This implies a gradient of 0.7 GeV/m, corresponding to a plasma-wave amplitude of more than 8%. The electron signal was below detection threshold without injection or when the laser was operated on a single frequency.

  5. Dual-frequency injection-locked continuous-wave near-infrared laser

    CERN Document Server

    Gavara, Trivikramarao; Sasaki, Yusuke; Kawashima, Takuya; Hamano, Hiroaki; Yoshizaki, Ryo; Fujimura, Yuki; Yoshii, Kazumichi; Ohae, Chiaki; Katsuragawa, Masayuki

    2016-01-01

    We report a dual-frequency injection-locked continuous-wave near-infrared laser. The entire system consists of a Ti:sapphire ring laser as a power oscillator, two independent diode-lasers employed as seed lasers, and a master cavity providing a frequency reference. Stable dual-frequency injection-locked oscillation is achieved with a maximum output power of 2.8 W. As fundamental performance features of this laser system, we show its single longitudinal/transverse mode characteristics and practical power stability. Furthermore, as advanced features, we demonstrate arbitrary selectivity of the two frequencies and flexible control of their relative powers by simply manipulating the seed lasers.

  6. High throughput laser processing

    Science.gov (United States)

    Harley, Gabriel; Pass, Thomas; Cousins, Peter John; Viatella, John

    2016-12-27

    A solar cell is formed using a solar cell ablation system. The ablation system includes a single laser source and several laser scanners. The laser scanners include a master laser scanner, with the rest of the laser scanners being slaved to the master laser scanner. A laser beam from the laser source is split into several laser beams, with the laser beams being scanned onto corresponding wafers using the laser scanners in accordance with one or more patterns. The laser beams may be scanned on the wafers using the same or different power levels of the laser source.

  7. [Lipolysis lasers].

    Science.gov (United States)

    Mazer, J-M

    2009-10-01

    We use lipolysis lasers for around five years. The principle of those lasers is that, for some wavelengths, the fat, located in the adipocytes reacts as a chromophor. In order to allow the direct exposure of the adipocytes to the optical fiber (around 1mm diameter), this has to be inserted in the hypodermis, then move back and forth inside the treated areas. The theorical benefits, compared to the liposuction procedures are related to the fact that the thermal effect of the laser emission allows to avoid laxity, sometimes observed after a liposuction. If we consider the first publications related to this emerging procedure, the profile of tolerance seems good, and even possibly better than the liposuctions. Nevertheless, this procedure with lasers is still a surgical procedure, exposing theorically to the side effects related in and after each surgery: infections, ecchymosis... Recently, some cases of severe side effects (infection of the skin, and necrosis) have been reported. They seem to be related to a homogeneous distribution of the energy inducing an excessive thermal injury. Some new improvements, with the last generation lasers, could allow us to avoid, or at least to dramatically reduce those side effects. The efficacy of those lasers is visibly satisfying; the key question is to precise the optimal modalities of use : in a surgery room, after an optimal training, with the last generation lasers?

  8. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    2008-01-01

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., frequency doubling in external cavities, reliable cw-parametric oscillators, tunable narrow-band UV sources, more sensitive detection techniques, tunable femtosecond and sub-femtosecond lasers (X-ray region and the attosecond range), control of atomic and molecular excitations, frequency combs able to synchronize independent femtosecond lasers, coherent matter waves, and still more applications in chemical analysis, medical diagnostics, and engineering.

  9. Laser spectroscopy

    CERN Document Server

    Demtröder, Wolfgang

    Keeping abreast of the latest techniques and applications, this new edition of the standard reference and graduate text on laser spectroscopy has been completely revised and expanded. While the general concept is unchanged, the new edition features a broad array of new material, e.g., ultrafast lasers (atto- and femto-second lasers) and parametric oscillators, coherent matter waves, Doppler-free Fourier spectroscopy with optical frequency combs, interference spectroscopy, quantum optics, the interferometric detection of gravitational waves and still more applications in chemical analysis, medical diagnostics, and engineering.

  10. He, Ne and Ar isotopic composition of Fe-Mn crusts from the western and central Pacific Ocean and implications for their genesis

    Institute of Scientific and Technical Information of China (English)

    BU WenRui; SHI XueFa; ZHANG MingJie; LIU JiHua; G.P. GLASBY

    2007-01-01

    The noble gas nuclide abundances and isotopic ratios of the upmost layer of Fe-Mn crusts from the western and central Pacific Ocean have been determined. The results indicate that the He and Ar nuclide abundances and isotopic ratios can be classified into two types: low 3He/4He type and high 3He/4He type. The low 3He/4He type is characterized by high 4He abundances of 191×10-9 cm3.STP.g-1 on average, with variable 4He, 20Ne and 40Ar abundances in the range (42.8-421)×10-9 cm3.STP.g-1, (5.40-141)×10-9 cm3.STP.g-1, and (773- 10976)×10-9 cm3.STP.g-1, respectively. The high 3He/4He samples are characterized by low 4He abundances of 11.7×10-9 cm3.STP.g-1 on average, with 4He, 20Ne and 40Ar abundances in the range of (7.57-17.4)×10-9 cm3.STP.g-1, (10.4-25.5)×10-9 cm3.STP.g-1 and (5354-9050)×10-9 cm3.STP.g-1, respectively. The low 3He/4He samples have 3He/4He ratios (with R/RA ratios of 2.04-2.92) which are lower than those of MORB (R/RA=8±1) and 40Ar/36Ar ratios (447-543) which are higher than those of air (295.5). The high 3He/4He samples have 3He/4He ratios (with R/RA ratios of 10.4-12.0) slightly higher than those of MORB (R/RA=8±1) and 40Ar/36Ar ratios (293-299) very similar to those of air (295.5). The Ne isotopic ratios (20Ne/22Ne and 21Ne/22Ne ratios of 10.3-10.9 and 0.02774-0.03039, respectively) and the 38Ar/36Ar ratios (0.1886-0.1963) have narrow ranges which are very similar to those of air (the 20Ne/22Ne, 21Ne/22Ne, 38Ar/36Ar ratios of 9.80, 0.029 and 0.187, respectively),and cannot be differentiated into different groups. The noble gas nuclide abundances and isotopic ratios, together with their regional variability, suggest that the noble gases in the Fe-Mn crusts originate primarily from the lower mantle. The low 3He/4He type and high 3He/4He type samples have noble gas characteristics similar to those of HIMU (High U/Pb Mantle)- and EM (Enriched Mantle)-type mantle material, respectively. The low 3He/4He type samples with HIMU-type noble gas isotopic ratios occur in the Magellan Seamounts, Marcus-Wake Seamounts, Marshall Island Chain and the Mid-Pacific Seamounts whereas the high 3He/4He type samples with EM-type noble gas isotopic ratios occur in the Line Island Chain. This difference in noble gas characteristics of these crust types implies that the Magellan Seamounts, Marcus-Wake Seamounts, Marshall Island Chain, and the Mid-Pacific Seamounts originated from HIMU-type lower mantle material whereas the Line Island Chain originated from EM-type lower mantle material. This finding is consistent with variations in the Pb-isotope and trace element signatures in the seamount lavas. Differences in the mantlesource may therefore be responsible for variations in the noble gas abundances and isotopic ratios in the Fe-Mn crusts. Mantle degassing appears to be the principal factor controlling noble gas isotopic abundances in Fe-Mn crusts. Decay of radioactive isotopes has a negligible influence on the nuclide abundances and isotopic ratios of noble gases in these crusts on the timescale of their formation.

  11. Multidiffusion mechanisms for noble gases (He, Ne, Ar) in silicate glasses and melts in the transition temperature domain: Implications for glass polymerization

    Science.gov (United States)

    Amalberti, Julien; Burnard, Pete; Laporte, Didier; Tissandier, Laurent; Neuville, Daniel R.

    2016-01-01

    Noble gases are ideal probes to study the structure of silicate glasses and melts as the modifications of the silicate network induced by the incorporation of noble gases are negligible. In addition, there are systematic variations in noble gas atomic radii and several noble gas isotopes with which the influence of the network itself on diffusion may be investigated. Noble gases are therefore ideally suited to constrain the time scales of magma degassing and cooling. In order to document noble gas diffusion behavior in silicate glass, we measured the diffusivities of three noble gases (4He, 20Ne and 40Ar) and the isotopic diffusivities of two Ar isotopes (36Ar and 40Ar) in two synthetic basaltic glasses (G1 and G2; 20Ne and 36Ar were only measured in sample G1). These new diffusion results are used to re-interpret time scales of the acquisition of fractionated atmospheric noble gas signatures in pumices. The noble gas bearing glasses were synthesized by exposing the liquids to high noble gas partial pressures at high temperature and pressure (1750-1770 K and 1.2 GPa) in a piston-cylinder apparatus. Diffusivities were measured by step heating the glasses between 423 and 1198 K and measuring the fraction of gas released at each temperature step by noble gas mass spectrometry. In addition we measured the viscosity of G1 between 996 and 1072 K in order to determine the precise glass transition temperature and to estimate network relaxation time scales. The results indicate that, to a first order, that the smaller the size of the diffusing atom, the greater its diffusivity at a given temperature: D(He) > D(Ne) > D(Ar) at constant T. Significantly, the diffusivities of the noble gases in the glasses investigated do not display simple Arrhenian behavior: there are well-defined departures from Arrhenian behavior which occur at lower temperatures for He than for Ne or Ar. We propose that the non-Arrhenian behavior of noble gases can be explained by structural modifications of the silicate network itself as the glass transition temperature is approached: as the available free volume (available site for diffusive jumps) is modified, noble gas diffusion is no longer solely temperature-activated but also becomes sensitive to the kinetics of network rearrangements. The non-Arrhenian behavior of noble gas diffusion close to Tg is well described by a modified Vogel-Tammann-Fulcher (VTF) equation: Finally, our step heating diffusion experiments suggest that at T close to Tg, noble gas isotopes may suffer kinetic fractionation at a degree larger than that predicted by Graham's law. In the case of 40Ar and 36Ar, the traditional assumption based on Graham's law is that the ratio D40Ar/D36Ar should be equal to 0.95 (the square root of the ratio of the mass of 36Ar over the mass of 40Ar). In our experiment with glass G1, D40Ar/D36Ar rapidly decreased with decreasing temperature, from near unity (0.98 ± 0.14) at T > 1040 K to 0.76 when close to Tg (T = 1003 K). Replicate experiments are needed to confirm the strong kinetic fractionation of heavy noble gases close to the transition temperature.

  12. He, Ne and Ar isotope compositions of fluid inclusions in hy-drothermal sulfides from the TAG hydrothermal field, Mid-Atlantic Ridge

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Helium, neon and argon isotope compositions of fluid inclusionshave been measured in hydrothermal sulfide samples from the TAG hydrothermal field at the Mid-Atlantic Ridge. Fluid-inclusion 3He/4He ratios are 2.2-13.3 times the air value (Ra), and with a mean of 7.2 Ra. Com-parison with the local vent fluids (3He/4He=7.5-8.2 Ra) and mid-ocean ridge basalt values (3He/4He=6-11 Ra) shows that the variation range of 3He/4He ratios from sulfide-hosted fluid inclu-sions is significantly large. Values for 20Ne/22Ne are from 10.2 to 11.4, which are significantly higher than the atmospheric ratio (9.8). And fluid-inclusion 40Ar/36Ar ratios range from 287 to 359, which are close to the atmospheric values (295.5). These results indicate that the noble gases of fluid inclu-sions in hydrothermal sulfides are a mixture of mantle- and seawater-derived noble gases; the partial mantle-derived components of trapped hydrothermal fluids may be from the lower mantle; the helium of fluid inclusions is mainly from upper mantle; and the Ne and Ar components are mainly from seawater.

  13. He, Ne and Ar isotope compositions of fluid inclusions in hy-drothermal sulfides from the TAG hydrothermal field, Mid-Atlantic Ridge

    Institute of Scientific and Technical Information of China (English)

    ZENG; Zhigang; (

    2001-01-01

    [1]Rona, P. A. , Klinkhammer, G. , Nelsen, T. A. et al. , Black smokers, massive sulphides and vent biota at the Mid-Atlantic Ridge, Nature, 1986, 321: 33.[2]Edmonds, H. N. , German, C. R. , Green, D. R. H. et al. , Continuation of the hydrothermal fluid chemistry time series at TAG, and the effects of ODP drilling, Geophys. Res. Lett., 1996, 23: 3487.[3]Charlou, J. L. , Donval, J. P. , Jean-Baptiste, P. et al. , Gases and helium isotopes in high temperature solutions sampled before and after ODP Leg158 drilling at TAG hydrothermal field (26°N, MAR), Geophys. Res. Lett., 1996, 23: 3491. [4]Rudnicki, M. D. , Elderfield, H. , Helium, radon and manganese at the TAG and Snakepit hydrothermal vent fields, 26°and 23°N, Mid-Atlantic Ridge, Earth Planet. Sci. Lett., 1992, 113: 307. [5]Butterfield, D. A. , Massoth, G. J. , McDuff, R. E. et al. , Geochemistry of fluids from Axial Seamount hydrothermal emissions study vent field, Juan de Fuca Ridge: Subseafloor boiling and subsequent fluid-rock interaction, Journal of Geophysical Research, 1990, 95: 12895. [6]Baker, E. T. , Lupton, J. E. , Changes in submarine hydrothermal 3He/heat ratios as an indicator of magmatic/tectonic activity, Nature, 1990, 346: 556. [7]Jean-Baptiste, P. , Fouquet, Y. , Abundance and isotopic composition of helium in hydrothermal sulfides from the East Pacific Rise at 13°N, Geochimica et Cosmochimica Acta, 1996, 60: 87. [8]Stuart, F. M. , Turner, G. , Duckworth, R. C. et al. , Helium isotopes as tracers of trapped hydrothermal fluids in ocean-floor sulfides, Geology, 1994, 22: 823. [9]Stuart, F. M. , Duckworth, R. , Turner, G. et al. , Helium and sulfur isotopes in sulfide minerals from Middle Valley, Northern Juan de Fuca Ridge, Proceedings of the Ocean Drilling Program, Scientific Results, 1994, 139: 387. [10]Turner, G. , Stuart, F. , Helium/heat ratios and deposition temperatures of sulphides from the ocean floor, Nature, 1992, 357: 581.[11]Elderfield, H. , Schultz, A. , Mid-ocean ridge hydrothermal fluxes and the chemical composition of the ocean, Annu. Rev. Earth Planet. Sci. , 1996, 24: 191.[12]Hou, Z. Q. , Li, Y. H. , Ai, Y. D. , The helium isotopic compositions of activity hydrothermal system in the Okinawa trough?/FONT>mantle-derived helium evidence, Science in China, Ser. D, 1999, 42(2): 155.[13]Herzig, P. M. , Petersen, S. , Hannington, M D. , Geochemistry and sulfur-isotopic composition of the TAG hydrothermal mound, Mid-Atlantic Ridge, 26°N, Proc ODP, Sci. Results, 1998, 158: 47.[14]Meyer, P. S. , Bryan, W. B. , Petrology of basaltic glasses from the TAG segment: Implications for a deep hydrothermal heat source, Geophysical Research Letters, 1996, 23: 3435.[15]Thompson, G. , Humphris, S. E. , Schroeder, B. et al. , Active vents and massive sulfides at 26°N (TAG) and 23°N (Snakepit) on the Mid-Atlantic Ridge, Canadian Mineralogist, 1988, 26: 697.[16]Lalou, C. , Reyss, J. L. , Brichet, E. et al. , Hydrothermal activity on a 105-year scale at a slow-spreading ridge, TAG hydrothermal field, Mid-Atlantic ridge 26°N, Journal of Geophysical Research, 1995, 100: 17855.[17]Stuart, F. M. , Turner, G. , Mantle-derived 40Ar in mid-ocean ridge hydrothermal fluids: implications for the source of volatiles and mantle degassing rates, Chemical Geology, 1998, 147: 77.[18]Lalou, C. , Reyss, J. L. , Brichet, E. et al. , New age data for Mid-Atlantic Ridge hydrothermal sites: TAG and Snakepit chronology revisited, Journal of Geophysical Research, 1993, 98: 9705.[19]Lalou, C. , Reyss, J. L. , Brichet, E. , Age of sub-bottom sulfide samples at the TAG active mound, Proc. ODP, Sci. Results, 1998, 158: 111.[20]You, C. F. , Bickle, M. J. , Evolution of an active sea-floor massive sulphide deposit, Nature, 1998, 394: 668.[21]Kurz, M. D. , Jenkins, W. J. , Schilling, J. G. et al. , Helium isotopic variations in the mantle beneath the central North Atlantic Ocean, Earth and Planetary Science Letters, 1982, 58: 1.[22]O’Nions, R. K. , Tolstikhin, I. N. , Behaviour and residence times of lithophile and rare gas tracers in the upper mantle, Earth and Planetary Science Letters, 1994, 124: 131.[23]Hiyagon, H. , Ozima, M. , Marty, B. et al. , Noble gases in submarine glasses from mid-oceanic ridges and Loihi seamount: Constraints on the early history of the earth, Geochimica et Cosmochimica Acta, 1992, 56: 1301.[24]Niedermann, S. , Bach, W. , Erzinger, J. , Noble gas evidence for a lower mantle component in MORBs from the southern East Pacific Rise: Decoupling of helium and neon isotope systematics, Geochim. Cosmochim. Acta, 1997, 61: 2697.[25]Sarda, P. , Staudacher, T. , Allegre, C. J. , Neon isotopes in submarine basalts, Earth and Planetary Science Letters, 1988, 91: 73.[26]Marty, B. , Neon and xenon isotopes in MORB: implications for the earth-atmosphere evolution, Earth Planet. Sci. Lett., 1989, 94: 45.[27]Allegre, C. J. , Staudacher, T. , Sarda, P. , Rare gas systematics: formation of the atmosphere, evolution and structure of the Earth’s mantle, Earth and Planetary Science Letters, 1986/87, 81: 127.[28]Langmuir, C. H. , Vocke, R. D. Jr. , Hanson, G. N. et al. , A general mixing equation with applications to Icelandic basalts, Earth and Planetary Science Letters, 1978, 37: 380.

  14. Intermolecular polarizabilities in H{sub 2}-rare-gas mixtures (H{sub 2}–He, Ne, Ar, Kr, Xe): Insight from collisional isotropic spectral properties

    Energy Technology Data Exchange (ETDEWEB)

    Głaz, Waldemar, E-mail: glaz@kielich.amu.edu.pl; Bancewicz, Tadeusz [Nonlinear Optics Division, Faculty of Physics, Adam Mickiewicz University, Umultowska 85, 61-614 Poznań (Poland); Godet, Jean-Luc [Laboratoire de photonique d’Angers, Université d’Angers, 2 boulevard Lavoisier, 49045 Angers (France); Gustafsson, Magnus [Department of Chemistry and Molecular Biology, University of Gothenburg, SE 412 96 Gothenburg (Sweden); Maroulis, George; Haskopoulos, Anastasios [Department of Chemistry, University of Patras, GR-26500 Patras (Greece)

    2014-08-21

    The report presents results of theoretical and numerical analysis of the electrical properties related to the isotropic part of the polarizability induced by interactions within compounds built up of a hydrogen H{sub 2} molecule and a set of noble gas atoms, Rg, ranging from the least massive helium up to the heaviest xenon perturber. The Cartesian components of the collisional polarizabilities of the H{sub 2}–Rg systems are found by means of the quantum chemistry methods and their dependence on the intermolecular distance is determined. On the basis of these data, the spherical, symmetry adapted components of the trace polarizability are derived in order to provide data sets that are convenient for evaluating collisional spectral profiles of the isotropic polarized part of light scattered by the H{sub 2}–Rg mixtures. Three independent methods of numerical computing of the spectral intensities are applied at room temperature (295 K). The properties of the roto-translational profiles obtained are discussed in order to determine the role played by contributions corresponding to each of the symmetry adapted parts of the trace polarizability. By spreading the analysis over the collection of the H{sub 2}–Rg systems, evolution of the spectral properties with the growing masses of the supermolecular compounds can be observed.

  15. Laser Refractography

    CERN Document Server

    Rinkevichyus, B.S; Raskovskaya, I.L

    2010-01-01

    This book describes the basic principles of laser refractography, a flexible new diagnostic tool for measuring optically inhomogeneous media and flows. Laser refractography is based on digital imaging and computer processing of structured laser beam refraction (SLR) in inhomogeneous transparent media. Laser refractograms provide both qualitative and quantitative measurements and can be used for the study of fast and transient processes. In this book, the theoretical basis of refractography is explored in some detail, and experimental setups are described for measurement of transparent media using either 2D (passed radiation) or 3D (scattered radiation) refractograms. Specific examples and applications are discussed, including visualization of the boundary layer near a hot or cold metallic ball in water, and observation of edge effects and microlayers in liquids and gases. As the first book to describe this new and exciting technique, this monograph has broad cross-disciplinary appeal and will be of interest t...

  16. Laser Dentistry

    Science.gov (United States)

    ... whitening procedures. What are the benefits of using dental lasers? There are several advantages. Dentists may not need to use a drill or administer anesthesia in some procedures, allowing the patient to enjoy ...

  17. Laser Optomechanics

    CERN Document Server

    Yang, Weijian; Ng, Kar Wei; Rao, Yi; Chase, Christopher; Chang-Hasnain, Connie J

    2015-01-01

    Cavity optomechanics explores the coupling between the optical field and the mechanical oscillation to induce cooling and regenerative oscillation in a mechanical oscillator. So far, optomechanics relies on the detuning between the cavity and an external pump laser, where the laser acts only as a power supply. Here, we report a new scheme with mutual coupling between a mechanical oscillator that supports a mirror of a vertical-cavity surface-emitting laser (VCSEL) and the optical field, greatly enhancing the light-matter energy transfer. In this work, we used an ultra-light-weight (130 pg) high-contrast-grating (HCG) mirror in a VCSEL, whose reflectivity spectrum is designed to facilitate strong optomechanical coupling, to demonstrate optomechanically-induced regenerative oscillation of the laser optomechanical cavity with > 550 nm self-oscillation amplitude of the micro-mechanical oscillator, two to three orders of magnitude larger than typical. This new scheme not only offers an efficient approach for high-...

  18. Il laser

    CERN Document Server

    Smith, William V

    1974-01-01

    Verso il 1960, il laser era ancora "una soluzione alla ricerca di un problema", ma fin dagli anni immediatamente successivi si è rivelato uno strumento insostituibile per le applicazioni più svariate.

  19. [Laser myringotomy].

    Science.gov (United States)

    Hassmann-Poznańska, Elzbieta; Skotnicka, Bozena

    2002-01-01

    The aim of the study was assessment of the qualities of laser-assisted myringotomy (LAM) as a treatment for acute and secretory otitis media. Laser-assisted myringotomy was performed on 65 children (113 ears) mean age 6.2 years diagnosed with secretory otitis media (80%), recurrent secretory otitis media (11%) and acute otitis media (9%). Myringotomy was performed under general anesthesia using the OtoLAM device (ESC/Sharplan, Israel). In 64 ears pressure equalisation tubes were inserted after fenestration of the tympanic membrane with laser. Adenoidectomy alone or with tonsillectomy was performed at the same time in 51 cases. Laser tympanostomies remained patent for 7-32 days. All tympanostomies healed with no noticeable scarring. LAM appears to be a safe, and easy to performed, alternative technique in the treatment of otitis media.

  20. A laser

    Energy Technology Data Exchange (ETDEWEB)

    Togo, N.

    1984-06-19

    It is reported that an improved laser design employing pumping of the active gas medium has been developed. A diagram of the laser system is given and its principle of operation is described in detail. Gas pumping is achieved using a pump whose oil reservoir is sealed by a sealing element. When the sealing element fails, the oil from the reservoir pollutes the laser substance. It is proposed that an additional oil reservoir pumping loop be used to maintain a lower pressure. The reservoir pressure is recorded by a sensor. When the sealing element fails, the pressure in the reservoir increases. The sensor records the change in pressure and generates a signal which shuts down the laser system. Thus, the possibility for oil penetration into the gas system is totally eliminated.

  1. Green lasers

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin

    2010-01-01

    Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range......Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range...

  2. Green lasers

    DEFF Research Database (Denmark)

    Jensen, Ole Bjarlin

    2010-01-01

    Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range......Well over a dozen papers at this year's Photonics West meeting in San Francisco boasted improvements in harmonic generation to produce visible laser beams, most of them in the green spectral range...

  3. Laser Physics and Laser Techniques

    Science.gov (United States)

    1989-06-01

    Other types of laser-assisted materials process- Planck Institute for Quantum Optics. Garching . West ing and machining, including laser cutting, welding...detectors with microstructured electrodes, 134[ G. N. Maracas. G. L. Harrs, C. A. Lee. and R. A. McFarlane. Opt. Le’tt., vol. 7, pp. 575-577, Dcc . 1982...A. E. Siegman Max-Planck Institut f’r Quantenoptik, D-8046 Garching , West Germany and E. L. Ginzton Laboratory, Stanford University, Stanford

  4. Ramsey-comb spectroscopy with intense ultrashort laser pulses

    CERN Document Server

    Morgenweg, Jonas; Eikema, Kjeld S E

    2014-01-01

    Optical frequency combs based on mode-locked lasers have revolutionised the field of metrology and precision spectroscopy by providing precisely calibrated optical frequencies and coherent pulse trains. Amplification of the pulsed output from these lasers is very desirable, as nonlinear processes can then be employed to cover a much wider range of transitions and wavelengths for ultra-high precision, direct frequency comb spectroscopy. Therefore full repetition rate laser amplifiers and enhancement resonators have been employed to produce up to microjoule-level pulse energies. Here we show that the full frequency comb accuracy and resolution can be obtained by using only two frequency comb pulses amplified to the millijoule pulse energy level, orders of magnitude more energetic than what has previously been possible. The novel properties of this approach, such as cancellation of optical light-shift effects, is demonstrated on weak two-photon transitions in atomic rubidium and caesium, thereby improving the fr...

  5. Early caries detection by laser induced fluorescence spectrum%早期龋齿的激光感生荧光光谱探测

    Institute of Scientific and Technical Information of China (English)

    刘莉; 唐静; 李颂战

    2009-01-01

    A non-invasive method adapted for optical diagnosis of early caries by using low-power He-Ne laser (λ=632.8 nm, 2.0±0.1 mW) was represented, and the comparison with the dental explorer, Photon undulatory Non-linear Conversion (PNC) method and DIAGNodent was given. This method without light filter, differed from the DIAGNodent and PNC method in its ability for registering fluorescence spectrum. The characteristic spectrum of dental tissue contained rich information such as dental components, structure, spatial conformation. The research was conducted in vitro. Three parts of characteristic spectrum including backscattering, reflection and auto-fluorescence were analyzed. It enables not only to evaluate chemical changes in tooth by analyzing characteristic frequencies of auto-fluorescence spectrum, but also to estimate structure and morphological changes in tissue by means of anti -stoke's fluorescence spectrum. Preliminary results show that this method has a potential application in the quantitive diagnosis of various stages of dental caries and is more sensitive for detecting early caries and the surface damage of health enamel.%提出了一种利用低功率He.Ne laser(λ=632.8mm,2.0±0.1 mW)光学无损诊断早期龋齿的方法,并与探诊方法、光子波动非线性转换方法(PNC)以及DIAGNodent龋齿诊断仪进行了比较.这种探测方法不使用滤光片,采集荧光光谱的能力与PNC方法和DIAGNodent龋齿诊断仪不同,所获得的牙齿特征光谱含有大量的关于牙齿成分、结构、空间构象等的信息.该项研究在离体牙齿上进行.牙齿的特征光谱由后向散射光、反射光、自体荧光3个部分组成,对自体荧光光谱的特征频率进行分析可以确定牙齿化学成分的改变,而对反斯托克斯荧光光谱进行分析则可以评价牙齿组织结构和形态学的变化.初步研究结果表明:文中方法在定量诊断各种龋齿方面极具应用潜力,对于探测早期龋齿、

  6. Laser therapy for cancer

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/patientinstructions/000905.htm Laser therapy for cancer To use the sharing features ... Lasers are also used on the skin. How Laser Therapy is Used Laser therapy can be used ...

  7. Laser acceleration

    Science.gov (United States)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  8. Header For Laser Diode

    Science.gov (United States)

    Rall, Jonathan A. R.; Spadin, Paul L.

    1990-01-01

    Header designed to contain laser diode. Output combined incoherently with outputs of other laser diodes in grating laser-beam combiner in optical communication system. Provides electrical connections to laser diode, cooling to thermally stabilize laser operation, and optomechanical adjustments that steer and focus laser beam. Range of adjustments provides for correction of worst-case decentering and defocusing of laser beam encountered with laser diodes. Mechanical configuration made simple to promote stability and keep cost low.

  9. Influence of electron beam irradiation on nonlinear optical properties of Al doped ZnO thin films for optoelectronic device applications in the cw laser regime

    Science.gov (United States)

    Antony, Albin; Pramodini, S.; Poornesh, P.; Kityk, I. V.; Fedorchuk, A. O.; Sanjeev, Ganesh

    2016-12-01

    We present the studies on third-order nonlinear optical properties of Al doped ZnO thin films irradiated with electron beam at different dose rate. Al doped ZnO thin films were deposited on a glass substrate by spray pyrolysis deposition technique. The thin films were irradiated using the 8 MeV electron beam from microtron ranging from 1 kG y to 5 kG y. Nonlinear optical studies were carried out by employing the single beam Z-scan technique to determine the sign and magnitude of absorptive and refractive nonlinearities of the irradiated thin films. Continuous wave He-Ne laser operating at 633 nm was used as source of excitation. The open aperture Z-scan measurements indicated the sample displays reverse saturable absorption (RSA) process. The negative sign of the nonlinear refractive index n2 was noted from the closed aperture Z-scan measurements indicates, the films exhibit self-defocusing property due to thermal nonlinearity. The third-order nonlinear optical susceptibility χ(3) varies from 8.17 × 10-5 esu to 1.39 × 10-3 esu with increase in electron beam irradiation. The present study reveals that the irradiation of electron beam leads to significant changes in the third-order optical nonlinearity. Al doped ZnO displays good optical power handling capability with optical clamping of about ∼5 mW. The irradiation study endorses that the Al doped ZnO under investigation is a promising candidate photonic device applications such as all-optical power limiting.

  10. Dyestuff laser

    Energy Technology Data Exchange (ETDEWEB)

    Brinkmann, U.; Raue, R.; Schellhammer, C.; Telle, H.

    1981-06-16

    Laser light in the wavelength range of 400 - 480 nm is obtained with a dyestuff laser containing a dyestuff of the general formula wherein E denotes one of the radicals R1-R4 independently of one another denote hydrogen, alkyl, trifluoromethyl, alkoxy, aralkoxy, halogen, alkenyloxy, the carboxyl, cyano, alkylsulphone, arylsulphone, carboxamide or sulphonamide group or the carboxylic acid ester group, or R1 and R2, or R3 and R4, conjointly represent a fused benzene ring and M and N independently of one another denote 0, 1 or 2, with the proviso that the radical E contains at least one sulphonic acid group if M and N represent 0, and wherein the radical E can be further substituted, in a solvent which does not interfere with the emission, at a concentration, which emits laser beams, of, preferably, 10-2 to 10-5 mols/liter.

  11. A laser

    Energy Technology Data Exchange (ETDEWEB)

    Togo, N.

    1984-06-19

    The development of an improved gas laser system employing pumping of the active gaseous medium is reported. The layout of the design is given and its principle of operation is described in detail. The oil reservoir in the vacuum pump which pumps the gas through the laser system is separated by a sealing element; when this element fails, the oil may pollute the active medium. It is proposed that an additional oil reservoir pumping loop be used with the pump that operates continuously and maintains a lower pressure in the reservoir. The pressure in the reservoir is monitored by a special sensor. When the sealing element fails, the pressure sensor records the pressure drop in the oil reservoir. A signal is then generated and the laser system ceases operation, and eliminates the possibility for the oil penetrating into the pumping system.

  12. A bidirectional dual-comb ring laser for simple and robust dual-comb spectroscopy

    CERN Document Server

    Ideguchi, Takuro; Kobayashi, Yohei; Goda, Keisuke

    2015-01-01

    Fourier-transform spectroscopy is an indispensable tool for analyzing chemical samples in scientific research as well as chemical and pharmaceutical industries. Recently, its measurement speed, sensitivity, and precision have been shown to be significantly enhanced by using dual frequency combs. However, wide acceptance of this technique is hindered by its requirement for two frequency combs and active stabilization of the combs. Here we overcome this predicament with a Kerr-lens mode-locked bidirectional ring laser that generates two frequency combs with slightly different pulse repetition rates and a tunable yet highly stable rate difference. This peculiar lasing principle builds on a slight difference in optical cavity length between two counter-propagating lasing modes due to Kerr lensing. Since these combs are produced by the one and same laser cavity, their relative coherence stays passively stable without the need for active stabilization. To show its utility, we demonstrate broadband dual-comb spectro...

  13. Laser barometer

    Science.gov (United States)

    Abercrombie, Kevin R.; Shiels, David; Rash, Tim

    2001-02-06

    A pressure measuring instrument that utilizes the change of the refractive index of a gas as a function of pressure and the coherent nature of a laser light to determine the barometric pressure within an environment. As the gas pressure in a closed environment varies, the index of refraction of the gas changes. The amount of change is a function of the gas pressure. By illuminating the gas with a laser light source, causing the wavelength of the light to change, pressure can be quantified by measuring the shift in fringes (alternating light and dark bands produced when coherent light is mixed) in an interferometer.

  14. Laser Heterodyning

    CERN Document Server

    Protopopov, Vladimir V

    2009-01-01

    Laser heterodyning is now a widespread optical technique, based on interference of two waves with slightly different frequencies within the sensitive area of a photo-detector. Its unique feature – preserving phase information about optical wave in the electrical signal of the photo-detector – finds numerous applications in various domains of applied optics and optoelectronics: in spectroscopy, polarimetry, radiometry, laser radars and Lidars, microscopy and other areas. The reader may be surprised by a variety of disciplines that this book covers and satisfied by detailed explanation of the phenomena. Very well illustrated, this book will be helpful for researches, postgraduates and students, working in applied optics.

  15. Combined liquid helium neon laser with magnesium sulfate and lidocaineNursing experience of treating phlebitis%硫酸镁与利多卡因混合液联合氦氖激光治疗静脉炎的护理体会

    Institute of Scientific and Technical Information of China (English)

    叶秀珍

    2015-01-01

    目的:观察硫酸镁与利多卡因混合液联合多功能氦氖激光治疗静脉炎的效果。方法将67例静脉炎患者随机分为实验组和对照组两组。实验组使用硫酸镁与利多卡因混合液联合氦氖激光治疗;对照组使用硫酸镁与利多卡因混合液外敷。结果实验组治疗静脉炎的效果明显高于对照组﹙P<0.05﹚。结论使用硫酸镁与利多卡因混合液联合氦氖激光治疗静脉炎的效果好,值得临床推广。%ObjectiveTo observe the Magnesium sulfate and lidocaine combined multifunctional He-Ne laser treatment of phlebitis.Method67 patients with phlebitis were randomLy divided into experimental group and control group two groups.The experimental group used Magnesium sulfate and lidocaine combined with helium neon laser treatment;The control group used Magnesium sulfate and lidocaine ointment.ResultExperimental treatment of phlebitis is obviously higher than that of the control group (P<0.05).Conclusion The use of Magnesium sulfate and lidocaine combined with helium neon laser for the treatment of phlebitis, It is worthy of clinical promotion.

  16. Laser device

    DEFF Research Database (Denmark)

    2013-01-01

    The present invention provides a light source for light circuits on a silicon platform. A vertical laser cavity is formed by a gain region arranged between a first mirror structure and a second mirror structure, both acting as mirrors, by forming a grating region including an active material...

  17. Nanowire Lasers

    Science.gov (United States)

    Couteau, C.; Larrue, A.; Wilhelm, C.; Soci, C.

    2015-05-01

    We review principles and trends in the use of semiconductor nanowires as gain media for stimulated emission and lasing. Semiconductor nanowires have recently been widely studied for use in integrated optoelectronic devices, such as light-emitting diodes (LEDs), solar cells, and transistors. Intensive research has also been conducted in the use of nanowires for subwavelength laser systems that take advantage of their quasione- dimensional (1D) nature, flexibility in material choice and combination, and intrinsic optoelectronic properties. First, we provide an overview on using quasi-1D nanowire systems to realize subwavelength lasers with efficient, directional, and low-threshold emission. We then describe the state of the art for nanowire lasers in terms of materials, geometry, andwavelength tunability.Next,we present the basics of lasing in semiconductor nanowires, define the key parameters for stimulated emission, and introduce the properties of nanowires. We then review advanced nanowire laser designs from the literature. Finally, we present interesting perspectives for low-threshold nanoscale light sources and optical interconnects. We intend to illustrate the potential of nanolasers inmany applications, such as nanophotonic devices that integrate electronics and photonics for next-generation optoelectronic devices. For instance, these building blocks for nanoscale photonics can be used for data storage and biomedical applications when coupled to on-chip characterization tools. These nanoscale monochromatic laser light sources promise breakthroughs in nanophotonics, as they can operate at room temperature, can potentially be electrically driven, and can yield a better understanding of intrinsic nanomaterial properties and surface-state effects in lowdimensional semiconductor systems.

  18. Nanowire Lasers

    Directory of Open Access Journals (Sweden)

    Couteau C.

    2015-05-01

    Full Text Available We review principles and trends in the use of semiconductor nanowires as gain media for stimulated emission and lasing. Semiconductor nanowires have recently been widely studied for use in integrated optoelectronic devices, such as light-emitting diodes (LEDs, solar cells, and transistors. Intensive research has also been conducted in the use of nanowires for subwavelength laser systems that take advantage of their quasione- dimensional (1D nature, flexibility in material choice and combination, and intrinsic optoelectronic properties. First, we provide an overview on using quasi-1D nanowire systems to realize subwavelength lasers with efficient, directional, and low-threshold emission. We then describe the state of the art for nanowire lasers in terms of materials, geometry, andwavelength tunability.Next,we present the basics of lasing in semiconductor nanowires, define the key parameters for stimulated emission, and introduce the properties of nanowires. We then review advanced nanowire laser designs from the literature. Finally, we present interesting perspectives for low-threshold nanoscale light sources and optical interconnects. We intend to illustrate the potential of nanolasers inmany applications, such as nanophotonic devices that integrate electronics and photonics for next-generation optoelectronic devices. For instance, these building blocks for nanoscale photonics can be used for data storage and biomedical applications when coupled to on-chip characterization tools. These nanoscale monochromatic laser light sources promise breakthroughs in nanophotonics, as they can operate at room temperature, can potentially be electrically driven, and can yield a better understanding of intrinsic nanomaterial properties and surface-state effects in lowdimensional semiconductor systems.

  19. Excimer Laser Technology

    CERN Document Server

    Basting, Dirk

    2005-01-01

    This comprehensive survey on Excimer Lasers investigates the current range of the technology, applications and devices of this commonly used laser source, as well as the future of new technologies, such as F2 laser technology. Additional chapters on optics, devices and laser systems complete this compact handbook. A must read for laser technology students, process application researchers, engineers or anyone interested in excimer laser technology. An effective and understandable introduction to the current and future status of excimer laser technology.

  20. Laser Development for Laser Fusion Applications

    Science.gov (United States)

    1978-09-01

    SLL 80 676 copy 1 SAN D78-2306 Unlimited Release UC-21 aM* m ml 8 H Laser Development for Laser Fusion Applications Research Progress...Printed Copy $6.00; Microfiche $3.00 Accession Number: 3885 Publication Date: Dec 01,1978 Title: Laser Development for Laser Fusion Applications...Document: Archive, RRI, DEW Descriptors, Keywords: Laser Development Fusion Application Oscillator Amplifier Geometry Electron Beam Iodine Hydrogen

  1. RILIS laser room

    CERN Multimedia

    2016-01-01

    Footage of the RILIS laser room at ISOLDE. The Resonance Ionization Laser Ion Source (RILIS) is a chemically selective ion source which relies on resonant excitation of atomic transitions using tunable laser radiation. This video shows you the laser table with the different lenses and optics as well as an overview of the RILIS laser setup. It also shows laser light with different colors and operation by the RILIS laser experts. The last part of the video shows you the laser path from the RILIS laser room into the ISOLDE GPS separator room where it enters the GPS separator magnet.

  2. RILIS laser room HD

    CERN Multimedia

    2016-01-01

    Footage of the RILIS laser room at ISOLDE. The Resonance Ionization Laser Ion Source (RILIS) is a chemically selective ion source which relies on resonant excitation of atomic transitions using tunable laser radiation. This video shows you the laser table with the different lenses and optics as well as an overview of the RILIS laser setup. It also shows laser light with different colors and operation by the RILIS laser experts. The last part of the video shows you the laser path from the RILIS laser room into the ISOLDE GPS separator room where it enters the GPS separator magnet.

  3. Laser Drilling Practical Applications

    CERN Document Server

    Yilbas, Bekir Sami

    2013-01-01

    This book introduces laser drilling processes including modelling, quality assessment of drilled holes, and laser drilling applications. It provides insights into the laser drilling process and the relation among the drilling parameters pertinent to improved end product quality. This book is written for engineers and scientists working on laser machining, particularly laser drilling.

  4. Mirrorless lasers

    Indian Academy of Sciences (India)

    Hema Ramachandran

    2002-02-01

    Experimental realization of mirrorless lasers in the last decade have resulted in hectic activity in this field, due to their novelty, simplicity and ruggedness and their great potential for application. In this article, I will review the various developments in this field in roughly chronological order, and discuss some possible applications of this exciting phenomenon, also termed as ‘random lasing’.

  5. Nanowire Lasers

    OpenAIRE

    Couteau C.; Larrue A.; Wilhelm C.; Soci C.

    2015-01-01

    We review principles and trends in the use of semiconductor nanowires as gain media for stimulated emission and lasing. Semiconductor nanowires have recently been widely studied for use in integrated optoelectronic devices, such as light-emitting diodes (LEDs), solar cells, and transistors. Intensive research has also been conducted in the use of nanowires for subwavelength laser systems that take advantage of their quasione- dimensional (1D) nature, fl...

  6. Laser Research Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Laser Research lab is thecenter for the development of new laser sources, nonlinear optical materials, frequency conversion processes and laser-based sensors for...

  7. Lasers in medicine.

    Science.gov (United States)

    Viherkoski, E

    1990-01-01

    Since its discovery, the laser has been intensively investigated and used in medicine, first in ophthalmology then in ear, nose and throat surgery, gynaecology, neurosurgery etc. Development spans from the ruby and argon lasers in outpatient eye surgery to the carbon dioxide and Nd:YAG lasers in the operating theatres and further on to the PDT-dye lasers, excimer and solid state angioplasty lasers or flash lamp pumped "gallstone cracker" lasers. The CO2-Nd: YAG laser combination will be described as the state-of-art surgical laser. This simultaneous, coaxial and coherent combination laser offers a new possibility to cut and coagulate effectively at the same time. Operating times are shortened and bleeding volumes minimised. The CO2-Nd: YAG laser represents a new type of interaction between laser and tissue, laser enhanced tissue absorption, which will be described.

  8. Laser therapy (image)

    Science.gov (United States)

    A laser is used for many medical purposes. Because the laser beam is so small and precise, it enables ... without injuring surrounding tissue. Some uses of the laser are retinal surgery, excision of lesions, and cauterization ...

  9. Laser-Driven Fusion.

    Science.gov (United States)

    Gibson, A. F.

    1980-01-01

    Discusses the present status and future prospects of laser-driven fusion. Current research (which is classified under three main headings: laser-matter interaction processes, compression, and laser development) is also presented. (HM)

  10. Gasdynamic lasers: an introduction

    Energy Technology Data Exchange (ETDEWEB)

    Anderson, J.D. Jr.

    1976-01-01

    The following topics are covered: elementary physics, thermodynamics and vibrational kinetics of the CO/sub 2/--N/sub 2/--H/sub 2/O or He gasdynamic laser, calculation of gasdynamic laser performance, comparison between theory and experiment, inversions behind normal shock waves, CO/sub 2/--N/sub 2/ gasdynamic lasers: state-of-the-art, the carbon monoxide gasdynamic laser, downstream mixing gasdynamic lasers, optical cavity considerations for gasdynamic lasers, aerodynamic windows, and diffusers. (MHR)

  11. Laser accidents: Being Prepared

    Energy Technology Data Exchange (ETDEWEB)

    Barat, K

    2003-01-24

    The goal of the Laser Safety Officer and any laser safety program is to prevent a laser accident from occurring, in particular an injury to a person's eyes. Most laser safety courses talk about laser accidents, causes, and types of injury. The purpose of this presentation is to present a plan for safety offices and users to follow in case of accident or injury from laser radiation.

  12. Semiconductor Laser Measurements Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The Semiconductor Laser Measurements Laboratory is equipped to investigate and characterize the lasing properties of semiconductor diode lasers. Lasing features such...

  13. Laser Protection TIL

    Data.gov (United States)

    Federal Laboratory Consortium — The Laser Protection TIL conducts research and analysis of laser protection materials along with integration schemes. The lab's objectives are to limit energy coming...

  14. Laser biophotonics

    Science.gov (United States)

    Bashkatov, A. N.; Genina, E. A.; Priezzhev, A. V.; Tuchin, V. V.

    2016-06-01

    This issue of Quantum Electronics presents the papers that reflect the state-of-the-art of laser technologies used in biomedical studies and medical practice. Among the new technologies, one can note the methods of correlation and Doppler spectroscopy, as well as THz spectroscopy, in which biologically significant molecules are characterised by specific resonances. The latter topic is considered in the paper by Nazarov et al., where the dielectric function of aqueous solutions of glucose and albumin is studied using pulsed THz spectroscopy.

  15. Synchronizing femtosecond laser with x-ray synchrotron operating at arbitrarily different frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Wonhyuk [Department of Physics, Soongsil University, Seoul 156-743 (Korea, Republic of); Lee, Sooheyong, E-mail: sooheyong@gmail.com [Korea Research Institute of Standards and Science, Daejeon 305-600 (Korea, Republic of); Eom, Intae, E-mail: neplus@postech.ac.kr [Pohang Accelerator Laboratory, Pohang 790-784 (Korea, Republic of); Landahl, Eric C. [Department of Physics, DePaul University, Chicago, Illinois 60614 (United States)

    2014-12-15

    The ability to synchronize a femtosecond laser to x-ray pulses is crucial for performing ultrafast time-resolved x-ray scattering experiments at synchrotrons. Conventionally, the task has been achieved by locking a harmonic frequency of the laser oscillator to the storage ring master radio-frequency (RF). However, when the frequency mismatch between the two sources cannot be compensated by small adjustments to the laser cavity length, synchronization to a harmonic frequency requires modifying the optical components of the laser system. We demonstrate a novel synchronization scheme, which is a flexible alternative for synchronizing these two sources operating at arbitrarily different frequencies. First, we find the greatest common divisor (GCD) of the two frequencies that is still within the limited tuning range of the laser cavity length. The GCD is generated by dividing down from the storage ring RF, and is separately multiplied up to provide a feedback signal for synchronizing the laser cavity. Unique to our scheme, the GCD also serves as a harmonic RF source for the laser amplifier such that only laser oscillator pulses at fixed integer multiples of the storage ring RF are selected for amplification and delivery to experiments. Our method is implemented at the Photon Test Facility beamline of Pohang Light Source where timing-jitter less than 4 ps (r.m.s.) is measured using a new shot-to-shot method.

  16. Visible Solid State Lasers

    NARCIS (Netherlands)

    Hikmet, R.A.M.

    2007-01-01

    Diode lasers can be found in various applications most notably in optical communication and optical storage. Visible lasers were until recently were all based on IR diode lasers. Using GaN, directly blue and violet emitting lasers have also been introduced to the market mainly in the area of optical

  17. Applications of Semiconductor Lasers

    Institute of Scientific and Technical Information of China (English)

    LI Te; SUN Yan-fang; NING Yong-qiang; WANG Li-jun

    2005-01-01

    An overview of the applications of semiconductor lasers is presented. Diode lasers are widely used today,and the most prevalent use of the laser is probably in CD and DVD drives for computers and audio/video media systems. Semiconductor lasers are also used in many other fields ranging from optical fiber communications to display,medicine and pumping sources.

  18. Visible Solid State Lasers

    NARCIS (Netherlands)

    Hikmet, R.A.M.

    2007-01-01

    Diode lasers can be found in various applications most notably in optical communication and optical storage. Visible lasers were until recently were all based on IR diode lasers. Using GaN, directly blue and violet emitting lasers have also been introduced to the market mainly in the area of optical

  19. Diode Pumped Fiber Laser.

    Science.gov (United States)

    1984-12-01

    FIBER LASERS I. Nd:YAG FIBER LASER FABRICATION .............. 5 A. FIBER GROWTH .......................... 5 B. FIBER PROCESSING 7...1.32 pm FIBER LASERS I. Nd:YAG FIBER LASER FABRICATION A. FIBER GROWTH The single crystal fibers used in this work were grown at Stanford University

  20. Obstacles to Laser Safety

    Energy Technology Data Exchange (ETDEWEB)

    Barat, K

    2005-04-25

    The growth of laser development & technology has been remarkable. Unfortunately, a number of traps or obstacles to laser safety have also developed with that growth. The goal of this article is to highlight those traps, in the hope that an aware laser user will avoid them. These traps have been the cause or contributing factor of many a preventable laser accident.

  1. Lasers in cosmetic dentistry.

    Science.gov (United States)

    Pang, Peter

    2008-01-01

    Lasers have become a necessary instrument in the esthetic restorative armamentarium. This article presents smile design guidelines for soft tissue lasers, as well as an overview of hard tissue procedures that may be performed using all-tissue lasers. The goal is to help dentists determine the appropriate laser for a given clinical situations.

  2. New laser materials for laser diode pumping

    Science.gov (United States)

    Jenssen, H. P.

    1990-01-01

    The potential advantages of laser diode pumped solid state lasers are many with high overall efficiency being the most important. In order to realize these advantages, the solid state laser material needs to be optimized for diode laser pumping and for the particular application. In the case of the Nd laser, materials with a longer upper level radiative lifetime are desirable. This is because the laser diode is fundamentally a cw source, and to obtain high energy storage, a long integration time is necessary. Fluoride crystals are investigated as host materials for the Nd laser and also for IR laser transitions in other rare earths, such as the 2 micron Ho laser and the 3 micron Er laser. The approach is to investigate both known crystals, such as BaY2F8, as well as new crystals such as NaYF8. Emphasis is on the growth and spectroscopy of BaY2F8. These two efforts are parallel efforts. The growth effort is aimed at establishing conditions for obtaining large, high quality boules for laser samples. This requires numerous experimental growth runs; however, from these runs, samples suitable for spectroscopy become available.

  3. Multibeam fiber laser cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove; Hansen, Klaus Schütt; Nielsen, Jakob Skov

    2009-01-01

    The appearance of the high power high brilliance fiber laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating Cutting laser, the CO2 laser. However, quality problems in fiber-laser...... cutting have until now limited its application to metal cutting. In this paper the first results of proof-of-principle Studies applying a new approach (patent pending) for laser cutting with high brightness and short wavelength lasers will be presented. In the approach, multibeam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from two single mode fiber lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W...

  4. Multibeam Fibre Laser Cutting

    DEFF Research Database (Denmark)

    Olsen, Flemming Ove

    The appearance of the high power high brilliance fibre laser has opened for new possibilities in laser materials processing. In laser cutting this laser has demonstrated high cutting performance compared to the dominating cutting laser, the CO2-laser. However, quality problems in fibre-laser...... cutting have until now limited its application in metal cutting. In this paper the first results of proof-of-principle studies applying a new approach (patent pending) for laser cutting with high brightness short wavelength lasers will be presented. In the approach, multi beam patterns are applied...... to control the melt flow out of the cut kerf resulting in improved cut quality in metal cutting. The beam patterns in this study are created by splitting up beams from 2 single mode fibre lasers and combining these beams into a pattern in the cut kerf. The results are obtained with a total of 550 W of single...

  5. Calibration and Testing of a Large-Scale Electric Gun for Shock Hugoniot Measurements

    Science.gov (United States)

    1993-10-01

    Fibre - optic coupler Figure 9: Single...break-beam arrangement. Beam Barrel displacing prism ’• • • •.__--I f He--Ne laser Laser line fi fi ter Fibre - optic cable Fibre - optic 0 coupler Figure...10: Dual break-beam arrangement. 16 Barrel Laser beams Flyer plate - 4 Photodetector Fibreoptic Figure 11: Thefront-on fibre optic impact

  6. High power fiber lasers

    Institute of Scientific and Technical Information of China (English)

    LOU Qi-hong; ZHOU Jun

    2007-01-01

    In this review article, the development of the double cladding optical fiber for high power fiber lasers is reviewed. The main technology for high power fiber lasers, including laser diode beam shaping, fiber laser pumping techniques, and amplification systems, are discussed in de-tail. 1050 W CW output and 133 W pulsed output are ob-tained in Shanghai Institute of Optics and Fine Mechanics, China. Finally, the applications of fiber lasers in industry are also reviewed.

  7. Laser Hardening of Metals

    Institute of Scientific and Technical Information of China (English)

    Institute for Laser Physics; V.A.Serebryakov; K.V.Gratzianov; A.S.Eremenko; A.A.Timopheev; SPBSUITMO; M.V.Volkov

    2006-01-01

    Results of experiments on laser hardening of various materials with intensity 109~1010W/cm2 are represented. Nd:glass laser with energy up to 45J with a pulse duration ~30ns was used as a source of ra diation. Comparative researches of the laser peening for the various target areas are fulfilled. Results of laser hardening were determined by the microstructure analysis. The new approach to creation of the industrial laser for peening is discussed.

  8. The laser in urology

    Science.gov (United States)

    Hofstetter, Alfons G.

    2002-10-01

    Laser is an acronym for a physical principle and means: Light Amplification by stimulated Emission of Radiation. This principle offers a lot of tissue/light effects caused by the parameters: power density/time and the special qualities of the laser light. Nowadays for diagnosis and therapy following lasers are used in urology: Krypton- and Dye-lasers as well as the Neodymium-YAG- (nd:YAG-), Holmium-YAG (Ho:YAG-), Diode-, Argon- and the CO2-lasers.

  9. Laser ablation principles and applications

    CERN Document Server

    1994-01-01

    Laser Ablation provides a broad picture of the current understanding of laser ablation and its many applications, from the views of key contributors to the field. Discussed are in detail the electronic processes in laser ablation of semiconductors and insulators, the post-ionization of laser-desorbed biomolecules, Fourier-transform mass spectroscopy, the interaction of laser radiation with organic polymers, laser ablation and optical surface damage, laser desorption/ablation with laser detection, and laser ablation of superconducting thin films.

  10. Laser-surface interactions

    CERN Document Server

    Ganeev, Rashid A

    2014-01-01

    This book is about the interaction of laser radiation with various surfaces at variable parameters of radiation. As a basic principle of classification we chose the energetic or intensity level of interaction of laser radiation with the surfaces. These two characteristics of laser radiation are the most important parameters defining entire spectrum of the processes occurring on the surfaces during interaction with electromagnetic waves. This is a first book containing a whole spectrum of the laser-surface interactions distinguished by the ranges of used laser intensity. It combines the surface response starting from extremely weak laser intensities (~1 W cm-2) up to the relativistic intensities (~1020 W cm-2 and higher). The book provides the basic information about lasers and acquaints the reader with both common applications of laser-surface interactions (laser-related printers, scanners, barcode readers, discs, material processing, military, holography, medicine, etc) and unusual uses of the processes on t...

  11. Ceramic Laser Materials

    Directory of Open Access Journals (Sweden)

    Guillermo Villalobos

    2012-02-01

    Full Text Available Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements.

  12. Ceramic Laser Materials

    Science.gov (United States)

    Sanghera, Jasbinder; Kim, Woohong; Villalobos, Guillermo; Shaw, Brandon; Baker, Colin; Frantz, Jesse; Sadowski, Bryan; Aggarwal, Ishwar

    2012-01-01

    Ceramic laser materials have come a long way since the first demonstration of lasing in 1964. Improvements in powder synthesis and ceramic sintering as well as novel ideas have led to notable achievements. These include the first Nd:yttrium aluminum garnet (YAG) ceramic laser in 1995, breaking the 1 KW mark in 2002 and then the remarkable demonstration of more than 100 KW output power from a YAG ceramic laser system in 2009. Additional developments have included highly doped microchip lasers, ultrashort pulse lasers, novel materials such as sesquioxides, fluoride ceramic lasers, selenide ceramic lasers in the 2 to 3 μm region, composite ceramic lasers for better thermal management, and single crystal lasers derived from polycrystalline ceramics. This paper highlights some of these notable achievements. PMID:28817044

  13. Dye laser chain for laser isotope separation

    Science.gov (United States)

    Doizi, Denis; Jaraudias, Jean; Pochon, E.; Salvetat, G.

    1993-05-01

    Uranium enrichment by laser isotope separation uses a three step operation which requires four visible wavelengths to boost an individual U235 isotope from a low lying atomic energy level to an autoionizing state. The visible wavelengths are delivered by dye lasers pumped by copper vapor lasers (CVL). In this particular talk, a single dye chain consisting of a master oscillator and amplifier stages will be described and some of its performance given.

  14. Chaos synchronization based on a continuous chaos control method in semiconductor lasers with optical feedback.

    Science.gov (United States)

    Murakami, A; Ohtsubo, J

    2001-06-01

    Chaos synchronization using a continuous chaos control method was studied in two identical chaotic laser systems consisting of semiconductor lasers and optical feedback from an external mirror. Numerical calculations for rate equations indicate that the stability of chaos synchronization depends significantly on the external mirror position. We performed a linear stability analysis for the rate equations. Our results show that the stability of the synchronization is much influenced by the mode interaction between the relaxation oscillation frequency of the semiconductor laser and the external cavity frequency. Due to this interaction, an intensive mode competition between the two frequencies destroys the synchronization, but stable synchronization can be achieved when the mode competition is very weak.

  15. Controlling Chaotic Lasers

    Science.gov (United States)

    Gills, Zelda; Roy, Rajarshi

    1995-01-01

    Irregular fluctuations in intensity have long plagued the operation of a wide variety of solid-state lasers. We are exploring the possibility of exploiting rather than avoiding a laser's chaotic output. As an important step in that direction, we have applied a novel control technique to stabilize a solid state laser. By making small periodic changes in only one input parameter of the laser, we are able to stabilize complex periodic waveforms and steady state behavior in the laser output. We demonstrate the application of this approach in a diode pumped Nd:/YAG laser system.

  16. Lasers in periodontics.

    Science.gov (United States)

    Elavarasu, Sugumari; Naveen, Devisree; Thangavelu, Arthiie

    2012-08-01

    Laser is one of the most captivating technologies in dental practice since Theodore Maiman in 1960 invented the ruby laser. Lasers in dentistry have revolutionized several areas of treatment in the last three and a half decades of the 20(th) century. Introduced as an alternative to mechanical cutting device, laser has now become an instrument of choice in many dental applications. Evidence suggests its use in initial periodontal therapy, surgery, and more recently, its utility in salvaging implant opens up a wide range of applications. More research with better designs are a necessity before lasers can become a part of dental armamentarium. This paper gives an insight to laser in periodontics.

  17. Laser cooling of solids

    OpenAIRE

    Nemova, Galina

    2009-01-01

    Parallel to advances in laser cooling of atoms and ions in dilute gas phase, which has progressed immensely, resulting in physics Nobel prizes in 1997 and 2001, major progress has recently been made in laser cooling of solids. I compare the physical nature of the laser cooling of atoms and ions with that of the laser cooling of solids. I point out all advantages of this new and very promising area of laser physics. Laser cooling of solids (optical refrigeration) at the present time can be lar...

  18. Effects of laser pretreatment on cells of broad bean in UV-B-induced damage protection%激光预处理可保护蚕豆细胞免受UV-B辐射的损伤

    Institute of Scientific and Technical Information of China (English)

    齐智; 岳明; 王勋陵

    2000-01-01

    The embryos of broad bean (Vicia faba L.) were irradiated for 5 min by a He-Ne laser (632.8 nm,1.63 J·mm-2) or for 1 min by a CO2 laser (1,060 nm,2.53 J·mm-2).Afterwards they were cultivated in Petri dish in the constant temperature incubator in Knop until the length of epicotyl of broad bean was perhaply 3 cm that could be treated by ultraviolet-B (UV-B) radiation.The epicotyl of broad bean was irradiated for 7 h by 1.02,3.03,4.52 kJ·m-2 UV-B respectively in the ambient condition of 70 μmol·m-2·s-1 photosynthetically active radiation (PAR) in the growth cabinet.According to the changes of content of MDA,ascorbate acid (AsA) and UV-B absorbing compounds (absorbance at 300 nm),the effects of protecting of laser to the epicotyl of broad bean from UV-B radiation were tested.The results showed that laser pretreatment on the embryos could enhance the resistance of UV-B stress in epicotyl.Comparing with the control (without UV-B or laser radiation) and UV-B radiation alone,the MDA content was decreased significantly while AsA content was increased in the condition of laser pretreatment.It was also found that laser pretreatment alone could improve the content of UV-B absorbing compounds.If laser pretreatment followed UV-B radiation,the content of UV-B absorbing compounds was improved higher than laser treatment and UV-B treatment respectively.We suppose that laser pretreatment could enhance stress resistance in plant by a pathway of increasing the content of AsA and UV-B absorbing compounds while decreasing the MDA concentration.%当蚕豆的胚被He-Ne激光(632.8 nm,1.63 J·mm-2)照射5 min或被CO2激光(1060 nm,2.53 J·mm-2) 照射1 min后,将其置入Knop营养液中进行恒温培养.当蚕豆的上胚轴长到大约3 cm时,在光背景(PAR)为70 μmol·m-2·s-1条件下,分别用1.02、3.03、4.52 kJ·m-2的UV-B 辐射蚕豆的上胚轴7 h.根据蚕豆丙二醛(MDA)、抗坏血酸(AsA)和UV-B吸收物的含量变化,来测试激光对UV-B照射蚕豆的上

  19. LASIK - Laser Eye Surgery

    Science.gov (United States)

    ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ... Uveitis Focus On Pediatric Ophthalmology Education Center Oculofacial Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center ...

  20. Laser Processing and Chemistry

    CERN Document Server

    Bäuerle, Dieter

    2011-01-01

    This book gives an overview of the fundamentals and applications of laser-matter interactions, in particular with regard to laser material processing. Special attention is given to laser-induced physical and chemical processes at gas-solid, liquid-solid, and solid-solid interfaces. Starting with the background physics, the book proceeds to examine applications of lasers in “standard” laser machining and laser chemical processing (LCP), including the patterning, coating, and modification of material surfaces. This fourth edition has been enlarged to cover the rapid advances in the understanding of the dynamics of materials under the action of ultrashort laser pulses, and to include a number of new topics, in particular the increasing importance of lasers in various different fields of surface functionalizations and nanotechnology. In two additional chapters, recent developments in biotechnology, medicine, art conservation and restoration are summarized. Graduate students, physicists, chemists, engineers, a...

  1. Transmyocardial Laser Revascularization

    Science.gov (United States)

    ... Vascular Access for Hemodialysis Ventricular Assist Devices Transmyocardial Laser Revascularization Like every other organ or tissue in ... bypass surgery, there is a procedure called transmyocardial laser revascularization, also called TMLR or TMR. TMLR cannot ...

  2. Wavelength sweepable laser source

    DEFF Research Database (Denmark)

    2014-01-01

    Wavelength sweepable laser source is disclosed, wherein the laser source is a semiconductor laser source adapted for generating laser light at a lasing wavelength. The laser source comprises a substrate, a first reflector, and a second reflector. The first and second reflector together defines...... and having a rest position, the second reflector and suspension together defining a microelectromechanical MEMS oscillator. The MEMS oscillator has a resonance frequency and is adapted for oscillating the second reflector on either side of the rest position.; The laser source further comprises electrical...... connections adapted for applying an electric field to the MEMS oscillator. Furthermore, a laser source system and a method of use of the laser source are disclosed....

  3. Laser in operative dentistry

    Directory of Open Access Journals (Sweden)

    E. Yasini

    1994-06-01

    Full Text Available Today laser has a lot of usage in medicine and dentistry. In the field of dentistry, laser is used in soft tissue surgery, sterilization of canals (in root canal therapy and in restorative dentistry laser is used for cavity preparation, caries removal, sealing the grooves (in preventive dentistry, etching enamel and dentin, composite polymerization and removal of tooth sensitivity. The use of Co2 lasers and Nd: YAG for cavity preparation, due to creating high heat causes darkness and cracks around the region of laser radiation. Also due to high temperature of these lasers, pulp damage is inevitable. So today, by using the Excimer laser especially the argon floride type with a wavelength of 193 nm, the problem of heat stress have been solved, but the use of lasers in dentistry, especially for cavity preparation needs more researches and evaluations.

  4. Laser surgery - skin

    Science.gov (United States)

    Surgery using a laser ... used is directly related to the type of surgery being performed and the color of the tissue ... Laser surgery can be used to: Close small blood vessels to reduce blood loss Remove warts , moles , sunspots, and ...

  5. Laser removal of tattoos.

    Science.gov (United States)

    Kuperman-Beade, M; Levine, V J; Ashinoff, R

    2001-01-01

    Tattoos are placed for different reasons. A technique for tattoo removal which produces selective removal of each tattoo pigment, with minimal risk of scarring, is needed. Nonspecific methods have a high incidence of scarring, textural, and pigmentary alterations compared with the use of Q-switched lasers. With new advances in Q-switched laser technology, tattoo removal can be achieved with minimal risk of scarring and permanent pigmentary alteration. There are five types of tattoos: amateur, professional, cosmetic, medicinal, and traumatic. Amateur tattoos require less treatment sessions than professional multicolored tattoos. Other factors to consider when evaluating tattoos for removal are: location, age and the skin type of the patient. Treatment should begin by obtaining a pre-operative history. Since treatment with the Q-switched lasers is painful, use of a local injection with lidocaine or topical anaesthesia cream may be used prior to laser treatment. Topical broad-spectrum antibacterial ointment is applied immediately following the procedure. Three types of lasers are currently used for tattoo removal: Q-switched ruby laser (694 nm), Q-switched Nd:YAG laser (532 nm, 1064 nm), and Q-switched alexandrite laser (755 nm). The Q-switched ruby and alexandrite lasers are useful for removing black, blue and green pigments. The Q-switched 532 nm Nd:YAG laser can be used to remove red pigments and the 1064 nm Nd:YAG laser is used for removal of black and blue pigments. The most common adverse effects following laser tattoo treatment with the Q-switched ruby laser include textural change, scarring, and pigmentary alteration. Transient hypopigmentation and textural changes have been reported in up to 50 and 12%, respectively, of patients treated with the Q-switched alexandrite laser. Hyperpigmentation and textural changes are infrequent adverse effects of the Q-switched Nd:YAG laser and the incidence of hypopigmentary changes is much lower than with the ruby laser

  6. Tunable laser optics

    CERN Document Server

    Duarte, FJ

    2015-01-01

    This Second Edition of a bestselling book describes the optics and optical principles needed to build lasers. It also highlights the optics instrumentation necessary to characterize laser emissions and focuses on laser-based optical instrumentation. The book emphasizes practical and utilitarian aspects of relevant optics including the essential theory. This revised, expanded, and improved edition contains new material on tunable lasers and discusses relevant topics in quantum optics.

  7. Laser cutting system

    Science.gov (United States)

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  8. CO2 laser modeling

    Science.gov (United States)

    Johnson, Barry

    1992-01-01

    The topics covered include the following: (1) CO2 laser kinetics modeling; (2) gas lifetimes in pulsed CO2 lasers; (3) frequency chirp and laser pulse spectral analysis; (4) LAWS A' Design Study; and (5) discharge circuit components for LAWS. The appendices include LAWS Memos, computer modeling of pulsed CO2 lasers for lidar applications, discharge circuit considerations for pulsed CO2 lidars, and presentation made at the Code RC Review.

  9. Photonic bandgap fiber lasers and multicore fiber lasers for next generation high power lasers

    DEFF Research Database (Denmark)

    Shirakawa, A.; Chen, M.; Suzuki, Y.

    2014-01-01

    Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA.......Photonic bandgap fiber lasers are realizing new laser spectra and nonlinearity mitigation that a conventional fiber laser cannot. Multicore fiber lasers are a promising tool for power scaling by coherent beam combination. © 2014 OSA....

  10. Application of Various Lasers to Laser Trimming Resistance System

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-feng

    2007-01-01

    Though the laser trimming resistance has been an old laser machining industry for over 30 years, the development of technology brings new alternative lasers which can be used for the traditional machining. The paper describes application of various lasers to laser trimming resistance system including early traditional krypton arc lamp pumped Nd:YAG to laser, modern popular diode pumped solid state laser and the present advanced harmonic diode pumped solid state laser. Using the new alternative lasers in the laser trimming resistance system can dramatically improve the yields and equipment performance.

  11. Zeeman laser gyroscopes

    Energy Technology Data Exchange (ETDEWEB)

    Azarova, V V; Golyaev, Yu D; Saveliev, I I [Open Joint-Stock Company M.F. Stel' makh Polyus Research Institute, Moscow (Russian Federation)

    2015-02-28

    The history of invention and development of Zeeman laser gyroscopes, specific features of their optical scheme and operation principle are described. The construction and element base of modern laser angular velocity sensors with Zeeman-based frequency biasing are considered. The problems and prospects of their development are discussed. (laser gyroscopes)

  12. Lasers for nonlinear microscopy.

    Science.gov (United States)

    Wise, Frank

    2013-03-01

    Various versions of nonlinear microscopy are revolutionizing the life sciences, almost all of which are made possible because of the development of ultrafast lasers. In this article, the main properties and technical features of short-pulse lasers used in nonlinear microscopy are summarized. Recent research results on fiber lasers that will impact future instruments are also discussed.

  13. Laser power transmission

    Science.gov (United States)

    Conway, Edmund J.

    1992-01-01

    An overview of previous studies related to laser power transmission is presented. Particular attention is given to the use of solar pumped lasers for space power applications. Three general laser mechanisms are addressed: photodissociation lasing driven by sunlight, photoexcitation lasing driven directly by sunlight, and photoexcitation lasing driven by thermal radiation.

  14. Laser Programs Highlights 1998

    Energy Technology Data Exchange (ETDEWEB)

    Lowdermilk, H.; Cassady, C.

    1999-12-01

    This report covers the following topics: Commentary; Laser Programs; Inertial Confinement Fusion/National Ignition Facility (ICF/NIF); Atomic Vapor Laser Isotope Separation (AVLIS); Laser Science and Technology (LS&T); Information Science and Technology Program (IS&T); Strategic Materials Applications Program (SMAP); Medical Technology Program (MTP) and Awards.

  15. On g -ray laser

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    We review various possibilities for realizing a g-ray laser. We conclude that, similar to the free-electron laser, it is practical to generate the g-ray laser by the stimulated emission of radiation from wiggling positrons channelled in a periodically bent crystal. It is the time to research this possi-bility both theoretically and experimentally with big efforts.

  16. LaserFest Celebration

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Alan Chodos; Elizabeth A. Rogan

    2011-08-25

    LaserFest was the yearlong celebration, during 2010, of the 50th anniversary of the demonstration of the first working laser. The goals of LaserFest were: to highlight the impact of the laser in its manifold commercial, industrial and medical applications, and as a tool for ongoing scientific research; to use the laser as one example that illustrates, more generally, the route from scientific innovation to technological application; to use the laser as a vehicle for outreach, to stimulate interest among students and the public in aspects of physical science; to recognize and honor the pioneers who developed the laser and its many applications; to increase awareness among policymakers of the importance of R&D funding as evidenced by such technology as lasers. One way in which LaserFest sought to meet its goals was to encourage relevant activities at a local level all across the country -- and also abroad -- that would be identified with the larger purposes of the celebration and would carry the LaserFest name. Organizers were encouraged to record and advertise these events through a continually updated web-based calendar. Four projects were explicitly detailed in the proposals: 1) LaserFest on the Road; 2) Videos; 3) Educational material; and 4) Laser Days.

  17. Laser bottom hole assembly

    Science.gov (United States)

    Underwood, Lance D; Norton, Ryan J; McKay, Ryan P; Mesnard, David R; Fraze, Jason D; Zediker, Mark S; Faircloth, Brian O

    2014-01-14

    There is provided for laser bottom hole assembly for providing a high power laser beam having greater than 5 kW of power for a laser mechanical drilling process to advance a borehole. This assembly utilizes a reverse Moineau motor type power section and provides a self-regulating system that addresses fluid flows relating to motive force, cooling and removal of cuttings.

  18. Diode laser and endoscopic laser surgery.

    Science.gov (United States)

    Sullins, Kenneth E

    2002-05-01

    Two functionally important differences exist between the diode laser and the carbon dioxide (CO2) laser (used more commonly in small animal surgery). Diode laser energy is delivered through a quartz fiber instead of being reflected through an articulated arm or waveguide. Quartz fibers are generally more flexible and resilient than waveguides and can be inserted through an endoscope for minimally invasive procedures. Laser-tissue interaction is the other significant difference. The CO2 laser is completely absorbed by water, which limits the effect to visible tissue. The diode wavelength is minimally absorbed by water and may affect tissue as deep as 10 mm below the surface in the free-beam mode. With proper respect for the tissue effect, these differences can be used to the advantage of the patient.

  19. Introduction to laser technology

    CERN Document Server

    Hitz, C Breck; Hecht, Jeff; Hitz, C Breck; John Wiley & Sons

    2001-01-01

    Electrical Engineering Introduction to Laser Technology , Third Edition. Would you like to know how a laser works, and how it can be modified for your own specific tasks? This intuitive third edition-previously published as Understanding Laser Technology , First and Second Editions-introduces engineers, scientists, technicians, and novices alike to the world of modern lasers, without delving into the mathematical details of quantum electronics. It is the only introductory text on the market today that explains the underlying physics and engineering applicable to all lasers. A unique combinatio.

  20. Lasers In Dentistry

    Directory of Open Access Journals (Sweden)

    Prasanth. S

    2011-07-01

    Full Text Available The uses of Lasers in dentistry have revolutionized several areas of treatment in the last three & a half decades of the 20th century. Initially it was used for ablating the hard tissues for acid etch treatment. Later Lasers were used for cutting, coagulation & cauterization of the soft tissues. It is also been used for the diagnosis of carious lesions& to test pulp vitality with Doppler. There are more than 40 uses for Laser. Initially Lasers were very expensive, but now they have become much cheaper. Portable models are available which have increased its versatility. Lasers will be the main weapon in the armamentarium of the dental surgeons.

  1. Tunable laser applications

    CERN Document Server

    Duarte, FJ

    2008-01-01

    Introduction F. J. Duarte Spectroscopic Applications of Tunable Optical Parametric Oscillators B. J. Orr, R. T. White, and Y. He Solid-State Dye Lasers Costela, I. García-Moreno, and R. Sastre Tunable Lasers Based on Dye-Doped Polymer Gain Media Incorporating Homogeneous Distributions of Functional Nanoparticles F. J. Duarte and R. O. James Broadly Tunable External-Cavity Semiconductor Lasers F. J. Duarte Tunable Fiber Lasers T. M. Shay and F. J. Duarte Fiber Laser Overview and Medical Applications

  2. Coherent laser beam combining

    CERN Document Server

    Brignon, Arnaud

    2013-01-01

    Recently, the improvement of diode pumping in solid state lasers and the development of double clad fiber lasers have allowed to maintain excellent laser beam quality with single mode fibers. However, the fiber output power if often limited below a power damage threshold. Coherent laser beam combining (CLBC) brings a solution to these limitations by identifying the most efficient architectures and allowing for excellent spectral and spatial quality. This knowledge will become critical for the design of the next generation high-power lasers and is of major interest to many industrial, environme

  3. Photoionization in alkali lasers.

    Science.gov (United States)

    Knize, R J; Zhdanov, B V; Shaffer, M K

    2011-04-11

    We have calculated photoionization rates in alkali lasers. The photoionization of alkali atoms in the gain medium of alkali lasers can significantly degrade the laser performance by reducing the neutral alkali density and with it the gain. For a ten atmosphere Rb laser and a Cs exciplex laser, the photoionization induced alkali atom loss rates are greater than 10(5) sec(-1). These high loss rates will quickly deplete the neutral alkali density, reducing gain, and may require fast, possibly, supersonic flow rates to sufficiently replenish the neutral medium for CW operation.

  4. Laser Diode Ignition (LDI)

    Science.gov (United States)

    Kass, William J.; Andrews, Larry A.; Boney, Craig M.; Chow, Weng W.; Clements, James W.; Merson, John A.; Salas, F. Jim; Williams, Randy J.; Hinkle, Lane R.

    1994-01-01

    This paper reviews the status of the Laser Diode Ignition (LDI) program at Sandia National Labs. One watt laser diodes have been characterized for use with a single explosive actuator. Extensive measurements of the effect of electrostatic discharge (ESD) pulses on the laser diode optical output have been made. Characterization of optical fiber and connectors over temperature has been done. Multiple laser diodes have been packaged to ignite multiple explosive devices and an eight element laser diode array has been recently tested by igniting eight explosive devices at predetermined 100 ms intervals.

  5. Quantum well lasers

    CERN Document Server

    Zory, Jr, Peter S; Kelley, Paul

    1993-01-01

    This book provides the information necessary for the reader to achieve a thorough understanding of all aspects of QW lasers - from the basic mechanism of optical gain, through the current technolgoical state of the art, to the future technologies of quantum wires and quantum dots. In view of the growing importance of QW lasers, this book should be read by all those with an active interest in laser science and technology, from the advanced student to the experienced laser scientist.* The first comprehensive book-length treatment of quantum well lasers* Provides a detailed treatment

  6. Semiconductor nanowire lasers

    Science.gov (United States)

    Eaton, Samuel W.; Fu, Anthony; Wong, Andrew B.; Ning, Cun-Zheng; Yang, Peidong

    2016-06-01

    The discovery and continued development of the laser has revolutionized both science and industry. The advent of miniaturized, semiconductor lasers has made this technology an integral part of everyday life. Exciting research continues with a new focus on nanowire lasers because of their great potential in the field of optoelectronics. In this Review, we explore the latest advancements in the development of nanowire lasers and offer our perspective on future improvements and trends. We discuss fundamental material considerations and the latest, most effective materials for nanowire lasers. A discussion of novel cavity designs and amplification methods is followed by some of the latest work on surface plasmon polariton nanowire lasers. Finally, exciting new reports of electrically pumped nanowire lasers with the potential for integrated optoelectronic applications are described.

  7. ORION laser target diagnostics.

    Science.gov (United States)

    Bentley, C D; Edwards, R D; Andrew, J E; James, S F; Gardner, M D; Comley, A J; Vaughan, K; Horsfield, C J; Rubery, M S; Rothman, S D; Daykin, S; Masoero, S J; Palmer, J B; Meadowcroft, A L; Williams, B M; Gumbrell, E T; Fyrth, J D; Brown, C R D; Hill, M P; Oades, K; Wright, M J; Hood, B A; Kemshall, P

    2012-10-01

    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  8. Alternate laser fusion drivers

    Energy Technology Data Exchange (ETDEWEB)

    Pleasance, L.D.

    1979-11-01

    Over the past few years, several laser systems have been considered as possible laser fusion drivers. Recently, there has been an increasing effort to evaluate these systems in terms of a reactor driver application. The specifications for such a system have become firmer and generally more restrictive. Several of the promising candidates such as the group VI laser, the metal vapor excimers and some solid state lasers can be eliminated on the basis of inefficiency. New solid state systems may impact the long range development of a fusion driver. Of the short wavelength gas lasers, the KrF laser used in conjunction with Raman compression and pulse stacking techniques is the most promising approach. Efficiencies approaching 10% may be possible with this system. While technically feasible, these approaches are complex and costly and are unsatisfying in an aethetic sense. A search for new lasers with more compelling features is still needed.

  9. Laser Applications in Orthodontics

    Science.gov (United States)

    Heidari, Somayeh; Torkan, Sepideh

    2013-01-01

    A laser is a collimated single wavelength of light which delivers a concentrated source of energy. Soon after different types of lasers were invented, investigators began to examine the effects of different wavelengths of laser energy on oral tissues, routine dental procedures and experimental applications. Orthodontists, along with other specialist in different fields of dentistry, can now benefit from several different advantages that lasers provide during the treatment process, from the beginning of the treatment, when separators are placed, to the time of resin residues removal from the tooth surface at the end of orthodontic treatment. This article outlines some of the most common usages of laser beam in orthodontics and also provides a comparison between laser and other conventional method that were the standard of care prior to the advent of laser in this field. PMID:25606324

  10. Lasers in orthodontics

    Science.gov (United States)

    Nalcaci, Ruhi; Cokakoglu, Serpil

    2013-01-01

    Many types of dental lasers are currently available that can be efficiently used for soft and hard tissue applications in the field of orthodontics. For achieving the desired effects in the target tissue, knowledge of laser characteristics such as power, wavelength and timing, is necessary. Laser therapy is advantageous because it often avoids bleeding, can be pain free, is non-invasive and is relatively quick. The high cost is its primary disadvantage. It is very important to take the necessary precautions to prevent possible tissue damage when using laser dental systems. Here, we reviewed the main types and characteristics of laser systems used in dental practice and discuss the applications of lasers in orthodontics, harmful effects and laser system safety. PMID:24966719

  11. Lasers in materials science

    CERN Document Server

    Ossi, Paolo; Zhigilei, Leonid

    2014-01-01

    This book covers various aspects of lasers in materials science, including a comprehensive overview on basic principles of laser-materials interactions and applications enabled by pulsed laser systems.  The material is organized in a coherent way, providing the reader with a harmonic architecture. While systematically covering the major current and emerging areas of lasers processing applications, the Volume provides examples of targeted modification of material properties achieved through careful control of the processing conditions and laser irradiation parameters. Special emphasis is placed on specific strategies aimed at nanoscale control of material structure and properties to match the stringent requirements of modern applications.  Laser fabrication of novel nanomaterials, which expands to the domains of photonics, photovoltaics, sensing, and biomedical applications, is also discussed in the Volume. This book assembles chapters based on lectures delivered at the Venice International School on Lasers...

  12. Flexible Laser Metal Cutting

    DEFF Research Database (Denmark)

    Villumsen, Sigurd; Jørgensen, Steffen Nordahl; Kristiansen, Morten

    2014-01-01

    This paper describes a new flexible and fast approach to laser cutting called ROBOCUT. Combined with CAD/CAM technology, laser cutting of metal provides the flexibility to perform one-of-a-kind cutting and hereby realises mass production of customised products. Today’s laser cutting techniques...... possess, despite their wide use in industry, limitations regarding speed and geometry. Research trends point towards remote laser cutting techniques which can improve speed and geometrical freedom and hereby the competitiveness of laser cutting compared to fixed-tool-based cutting technology...... such as punching. This paper presents the concepts and preliminary test results of the ROBOCUT laser cutting technology, a technology which potentially can revolutionise laser cutting....

  13. Mode selection laser

    DEFF Research Database (Denmark)

    2014-01-01

    The invention relates to a semiconductor mode selection laser, particularly to a VCSEL laser (200) having mode selection properties. The mode selection capability of the laser is achieved by configuring one of the reflectors (15,51) in the resonance cavity so that a reflectivity of the reflector...... (15) varies spatially in one dimension or two dimensions. Accordingly, the reflector (15) with spatially varying reflectivity is part both of the resonance cavity and the mode selection functionality of the laser. A plurality of the lasers configured with different mode selectors, i.e. different...... spatial reflector variations, may be combined to generate a laser beam containing a plurality of orthogonal modes. The laser beam may be injected into a few- mode optical fiber, e.g. for the purpose of optical communication. The VCSEL may have intra-cavity contacts (31,37) and a Tunnel junction (33...

  14. Nanofabrication with pulsed lasers.

    Science.gov (United States)

    Kabashin, Av; Delaporte, Ph; Pereira, A; Grojo, D; Torres, R; Sarnet, Th; Sentis, M

    2010-02-24

    An overview of pulsed laser-assisted methods for nanofabrication, which are currently developed in our Institute (LP3), is presented. The methods compass a variety of possibilities for material nanostructuring offered by laser-matter interactions and imply either the nanostructuring of the laser-illuminated surface itself, as in cases of direct laser ablation or laser plasma-assisted treatment of semiconductors to form light-absorbing and light-emitting nano-architectures, as well as periodic nanoarrays, or laser-assisted production of nanoclusters and their controlled growth in gaseous or liquid medium to form nanostructured films or colloidal nanoparticles. Nanomaterials synthesized by laser-assisted methods have a variety of unique properties, not reproducible by any other route, and are of importance for photovoltaics, optoelectronics, biological sensing, imaging and therapeutics.

  15. ORION laser target diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Bentley, C. D.; Edwards, R. D.; Andrew, J. E.; James, S. F.; Gardner, M. D.; Comley, A. J.; Vaughan, K.; Horsfield, C. J.; Rubery, M. S.; Rothman, S. D.; Daykin, S.; Masoero, S. J.; Palmer, J. B.; Meadowcroft, A. L.; Williams, B. M.; Gumbrell, E. T.; Fyrth, J. D.; Brown, C. R. D.; Hill, M. P.; Oades, K. [Plasma Physics Department, Atomic Weapons Establishment, Aldermaston, Reading, Berkshire RG7 4PR (United Kingdom); and others

    2012-10-15

    The ORION laser facility is one of the UK's premier laser facilities which became operational at AWE in 2010. Its primary mission is one of stockpile stewardship, ORION will extend the UK's experimental plasma physics capability to the high temperature, high density regime relevant to Atomic Weapons Establishment's (AWE) program. The ORION laser combines ten laser beams operating in the ns regime with two sub ps short pulse chirped pulse amplification beams. This gives the UK a unique combined long pulse/short pulse laser capability which is not only available to AWE personnel but also gives access to our international partners and visiting UK academia. The ORION laser facility is equipped with a comprehensive suite of some 45 diagnostics covering optical, particle, and x-ray diagnostics all able to image the laser target interaction point. This paper focuses on a small selection of these diagnostics.

  16. Raman fiber lasers

    Science.gov (United States)

    Supradeepa, V. R.; Feng, Yan; Nicholson, Jeffrey W.

    2017-02-01

    High-power fiber lasers have seen tremendous development in the last decade, with output powers exceeding multiple kilowatts from a single fiber. Ytterbium has been at the forefront as the primary rare-earth-doped gain medium owing to its inherent material advantages. However, for this reason, the lasers are largely confined to the narrow emission wavelength region of ytterbium. Power scaling at other wavelength regions has lagged significantly, and a large number of applications rely upon the diversity of emission wavelengths. Currently, Raman fiber lasers are the only known wavelength agile, scalable, high-power fiber laser technology that can span the wavelength spectrum. In this review, we address the technology of Raman fiber lasers, specifically focused on the most recent developments. We will also discuss several applications of Raman fiber lasers in laser pumping, frequency conversion, optical communications and biology.

  17. Laser physics and physiology.

    Science.gov (United States)

    Pierce, L A

    1997-01-01

    Laser light begins when an excited and unstable electron moves from its unstable state back to a more stable state producing energy in the form of a photon. Laser light is coherent which means that the light waves move in phase together in space and time. Laser light is monochromatic which means it is comprised of only one color or wavelength. Laser light is also collimated which means it is perfectly parallel and travels in a single direction with very little divergence. Medical lasers fall in the infrared and visible as well as ultraviolet portion of the electromagnetic spectrum and are available at different wavelengths. The wavelength of each laser partially determines the effect it will have on tissue. A specific wavelength or color can be used to selectively target a specific tissue such as hemoglobin, water, or melanin. Heat is produced by the laser, destroying the targeted tissues.

  18. Tunable lasers for waste management photochemistry applications. [Dye lasers, excimer lasers, IR lasers

    Energy Technology Data Exchange (ETDEWEB)

    Finch, F.T. (comp.)

    1978-09-01

    A review of lasers with potential photochemical applications in waste management indicates that dye lasers, as a class, can provide tunable laser output through the visible and near-uv regions of the spectrum of most interest to photochemistry. Many variables can affect the performance of a specific dye laser, and the interactions of these variables, at the current state of the art, are complex. The recent literature on dye-laser characteristics has been reviewed and summarized, with emphasis on those parameters that most likely will affect the scaling of dye lasers in photochemical applications. Current costs are reviewed and correlated with output power. A new class of efficient uv lasers that appear to be scalable in both energy output and pulse rate, based on rare-gas halide excimers and similar molecules, is certain to find major applications in photochemistry. Because the most important developments are too recent to be adequately described in the literature or are the likely outcome of current experiments, the basic physics underlying the class of excimer lasers is described. Specific cost data are unavailable, but these new gas lasers should reflect costs similar to those of existing gas lasers, in particular, the pulsed CO/sub 2/ lasers. To complete the survey of tunable-laser characteristics, the technical characteristics of the various classes of lasers in the ir are summarized. Important developments in ir laser technology are being accelerated by isotope-separation research, but, initially at least, this portion of the spectrum is least likely to receive emphasis in waste-management-oriented photochemistry.

  19. Lasers in space

    Science.gov (United States)

    Michaelis, M. M.; Forbes, A.; Bingham, R.; Kellett, B. J.; Mathye, A.

    2008-05-01

    A variety of laser applications in space, past, present, future and far future are reviewed together with the contributions of some of the scientists and engineers involved, especially those that happen to have South African connections. Historically, two of the earliest laser applications in space, were atmospheric LIDAR and lunar ranging. These applications involved atmospheric physicists, several astronauts and many of the staff recruited into the Soviet and North American lunar exploration programmes. There is a strong interest in South Africa in both LIDAR and lunar ranging. Shortly after the birth of the laser (and even just prior) theoretical work on photonic propulsion and space propulsion by laser ablation was initiated by Georgii Marx, Arthur Kantrowitz and Eugen Saenger. Present or near future experimental programs are developing in the following fields: laser ablation propulsion, possibly coupled with rail gun or gas gun propulsion; interplanetary laser transmission; laser altimetry; gravity wave detection by space based Michelson interferometry; the de-orbiting of space debris by high power lasers; atom laser interferometry in space. Far future applications of laser-photonic space-propulsion were also pioneered by Carl Sagan and Robert Forward. They envisaged means of putting Saenger's ideas into practice. Forward also invented a laser based method for manufacturing solid antimatter or SANTIM, well before the ongoing experiments at CERN with anti-hydrogen production and laser-trapping. SANTIM would be an ideal propellant for interstellar missions if it could be manufactured in sufficient quantities. It would be equally useful as a power source for the transmission of information over light year distances. We briefly mention military lasers. Last but not least, we address naturally occurring lasers in space and pose the question: "did the Big Bang lase?"

  20. Optical coatings for fiber lasers

    Institute of Scientific and Technical Information of China (English)

    HONG Dong-mei; ZHU Zhen; YUE Wei

    2005-01-01

    Fiber laser is the future development direction for the high energy lasers. This paper describs two kinds of optical coatings for fiber laser, including long and short wave pass filters. The one characteristic of fiber laser coatings lies in that coatings should separate two closely wavelength light including laser pump wavelength (980 nm) and laser irradiation wavelength(1 050~1 100 nm). At the same time, the coatings should have high laser damage threshold.