WorldWideScience

Sample records for current laser applications

  1. Current military laser applications

    Energy Technology Data Exchange (ETDEWEB)

    Flinchbaugh, D.E.

    1975-08-01

    Several important military applications with the predominant laser type used are reviewed. Most of these lasers are infrared lasers of one sort or another. Airborne tactical programs utilizing laser designator/illuminators are pictorially summarized, including range finding, target seeking, designation, tracking, reconnaissance, and surveillance. A typical designator optical system configuration is presented and discussed. Examples of operational laser systems are given. It is seen that many of the laser applications in the civilian community have either direct or indirect analogs in the military field. A self-contained HF/DF chemical laser weapon that recirculates its by-products is examined.

  2. The current status of laser applications in dentistry.

    Science.gov (United States)

    Walsh, L J

    2003-09-01

    A range of lasers is now available for use in dentistry. This paper summarizes key current and emerging applications for lasers in clinical practice. A major diagnostic application of low power lasers is the detection of caries, using fluorescence elicited from hydroxyapatite or from bacterial by-products. Laser fluorescence is an effective method for detecting and quantifying incipient occlusal and cervical carious lesions, and with further refinement could be used in the same manner for proximal lesions. Photoactivated dye techniques have been developed which use low power lasers to elicit a photochemical reaction. Photoactivated dye techniques can be used to disinfect root canals, periodontal pockets, cavity preparations and sites of peri-implantitis. Using similar principles, more powerful lasers can be used for photodynamic therapy in the treatment of malignancies of the oral mucosa. Laser-driven photochemical reactions can also be used for tooth whitening. In combination with fluoride, laser irradiation can improve the resistance of tooth structure to demineralization, and this application is of particular benefit for susceptible sites in high caries risk patients. Laser technology for caries removal, cavity preparation and soft tissue surgery is at a high state of refinement, having had several decades of development up to the present time. Used in conjunction with or as a replacement for traditional methods, it is expected that specific laser technologies will become an essential component of contemporary dental practice over the next decade.

  3. Application of x-ray lasers to current and future experiments in atomic and molecular physics

    International Nuclear Information System (INIS)

    Caldwell, C. Denise

    1995-01-01

    The use of intrinsically narrow-banded, intense x-ray lasers has the potential for a significant impact in atomic and molecular physics. As with any new technology, it is impossible to predict all the new information which may emerge as the technology develops. At least at the beginning it will be important for these lasers to have applicability to existing experimental methods, which can then exploit the new tool for experiments which are currently barely feasible with existing and planned sources of radiation in the high-energy regime. Examples of these are: resonant Auger decay, particularly of dilute species, studied with electron spectrometry; multi-photon processes involving the simultaneous utilization of two laser photons; and fragmentation experiments in which the high-energy photon is one of a pump-probe pair. Results from these experiments will go a long way to suggesting directions for future study

  4. 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.

  5. Current-enhanced SASE using an optical laser and its application to the LCLS

    International Nuclear Information System (INIS)

    Zholents, Alexander A.; Fawley, William M.; Emma, Paul; Huang, Zhirong; Reiche, Sven; Stupakov, Gennady

    2004-01-01

    We propose a significant enhancement of the electron peak current entering a SASE undulator by inducing an energy modulation in an upstream wiggler magnet via resonant interaction with an optical laser, followed by microbunching of the energy-modulated electrons at the accelerator exit. This current enhancement allows a reduction of the FEL gain length. The x-ray output consists of a series of uniformly spaced spikes, each spike being temporally coherent. The duration of this series is controlled by the laser pulse and in principle can be narrowed down to just a single, 200-attosecond spike. Given potentially absolute temporal synchronization of the x-ray spikes to the energy-modulating laser pulse, this scheme naturally makes pump-probe experiments available to SASE FEL's. We also study various detrimental effects related to the high electron peak current

  6. Excimer laser applications

    International Nuclear Information System (INIS)

    Fantoni, R.

    1988-01-01

    This lecture deals with laser induced material photoprocessing, especially concerning those processes which are initiated by u.v. lasers (mostly excimer laser). Advantages of using the u.v. radiation emitted by excimer lasers, both in photophysical and photochemical processes of different materials, are discussed in detail. Applications concerning microelectronics are stressed with respect to other applications in different fields (organic chemistry, medicine). As further applications of excimer lasers, main spectroscopic techniques for ''on line'' diagnostics which employ excimer pumped dye lasers, emitting tunable radiation in the visible and near u.v. are reviewed

  7. Laser interstitial thermotherapy application for breast surgery: Current situation and new trends.

    Science.gov (United States)

    Kerbage, Yohan; Betrouni, Nacim; Collinet, Pierre; Azaïs, Henri; Mordon, Serge; Dewalle-Vignion, Anne-Sophie; Merlot, Benjamin

    2017-06-01

    While breast specialists debate on therapeutic de-escalation in breast cancer, the treatment of benign lesions is also discussed in relation to new percutaneous ablation techniques. The purpose of these innovations is to minimize potential morbidity. Laser Interstitial ThermoTherapy (LITT) is an option for the ablation of targeted nodules. This review evaluated the scientific publications investigating the LITT approach in malignant and benign breast disease. Three preclinical studies and eight clinical studies (2 studies including fibroadenomas and 6 studies including breast cancers) were reviewed. Although the feasibility and safety of LITT have been confirmed in a phase I trial, heterogeneous inclusion criteria and methods seem to be the main reason for LITT not being yet an extensively used treatment option. In conclusion, further development is necessary before this technique can be used in daily practice. Copyright © 2017 Elsevier Ltd. All rights reserved.

  8. Lasers Fundamentals and Applications

    CERN Document Server

    Thyagarajan, K

    2010-01-01

    Lasers: Fundamentals and Applications, serves as a vital textbook to accompany undergraduate and graduate courses on lasers and their applications. Ever since their invention in 1960, lasers have assumed tremendous importance in the fields of science, engineering and technology because of their diverse uses in basic research and countless technological applications. This book provides a coherent presentation of the basic physics behind the way lasers work, and presents some of their most important applications in vivid detail. After reading this book, students will understand how to apply the concepts found within to practical, tangible situations. This textbook includes worked-out examples and exercises to enhance understanding, and the preface shows lecturers how to most beneficially match the textbook with their course curricula. The book includes several recent Nobel Lectures, which will further expose students to the emerging applications and excitement of working with lasers. Students who study lasers, ...

  9. 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

  10. Applications of soft x-ray lasers

    International Nuclear Information System (INIS)

    Skinner, C.H.

    1993-01-01

    The high brightness and short pulse duration of soft x-ray lasers provide unique advantages for novel applications. Imaging of biological specimens using x-ray lasers has been demonstrated by several groups. Other applications to fields such as chemistry, material science, plasma diagnostics, and lithography are beginning to emerge. We review the current status of soft x-ray lasers from the perspective of applications, and present an overview of the applications currently being developed

  11. MRI-guided laser interstitial thermal therapy in neuro-oncology: a review of its current clinical applications.

    Science.gov (United States)

    Rahmathulla, Gazanfar; Recinos, Pablo F; Kamian, Kambiz; Mohammadi, Alireza M; Ahluwalia, Manmeet S; Barnett, Gene H

    2014-01-01

    Magnetic resonance imaging-guided laser interstitial thermal therapy (LITT) is a minimally invasive treatment modality with recent increasing use to ablate brain tumors. When originally introduced in the late 1980s, the inability to precisely monitor and control the thermal ablation limited the adoption of LITT in neuro-oncology. Popularized as a means of destroying malignant hepatic and renal metastatic lesions percutaneously, its selective thermal tumor destruction and preservation of adjacent normal tissues have since been optimized for use in neuro-oncology. The progress made in real-time thermal imaging with MRI, laser probe design, and computer algorithms predictive of tissue kill has led to the resurgence of interest in LITT as a means to ablate brain tumors. Current LITT systems offer a surgical option for some inoperable brain tumors. We discuss the origins, principles, current indications, and future directions of MRI-guided LITT in neuro-oncology. © 2014 S. Karger AG, Basel.

  12. 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.

  13. Clinical applications of dental lasers.

    Science.gov (United States)

    Lomke, Mitchell A

    2009-01-01

    Dental lasers currently have 24 clinical indications for use that are recognized by the FDA. This article explores the scientific basis for these clinical indications in patient diagnosis and treatment. Multiple examples of relevant clinical applications for these wavelengths are explored in detail and illustrated via clinical photographs.

  14. Laser applications in neurosurgery

    Science.gov (United States)

    Cerullo, Leonard J.

    1985-09-01

    The "false start" of the laser in neurosurgery should not be misconstrued as a denial of the inherent advantages of precision and gentleness in dealing with neural tissue. Rather, early investigators were frustrated by unrealistic expectations, cumbersome equipment, and a general ignorance of microtechnique. By the early 70s, microneurosurgery was well established, surgical laser equipment for free hand and microlinked application had been developed, and a more realistic view of the limitations of the laser had been established. Consequently, the late 70s really heralded the renaissance of the laser in neurosurgery. Since then, there has been an overwhelming acceptance of the tool in a variety of clinical situations, broadly categorized in five groups. 1)|Perhaps the most generally accepted area is in the removal of extra-axial tumors of the brain and spinal cord. These tumors, benign by histology but treacherous by location, do not present until a significant amount of neurological compensation has already occurred. The application of additional trauma to the neural tissue, whether by further tumor growth or surgical manipulation, frequently results in irreversible damage. Here, the ability of the laser to vaporize tissue, in a fairly hemostatic fashion, without mechanical or thermal damage to sensitive surrounding tissues, is essential. 2)|The ability to incise delicate neural tissue with minimal spread of thermal destruction to adjacent functioning tissue makes the laser the ideal instrument when tumors deep under the surface are encountered in the brain or spinal cord. Thus, the second group of applications is in the transgression of normal neural structures to arrive at deeper pathological tissue. 3)|The third area of benefit for the laser in neurosurgery has been in the performance of neuroablative procedures, calling for deliberate destruction of functioning neural tissue in a controlled fashion. Again, the precision and shape confinement of the destructive

  15. Applications of lasers and electro-optics

    International Nuclear Information System (INIS)

    Tan, B.C.; Low, K.S.; Chen, Y.H.; Harith bin Ahmad; Tou, T.Y.

    1994-01-01

    Supported by the IRPA Programme on Laser Technology and Applications, many types of lasers have been designed, constructed and applied in various areas of science, medicine and industries. Amongst these lasers constructed were high power carbon dioxide lasers, rare gas halide excimer lasers, solid state Neodymium-YAG lasers, nitrogen lasers, flashlamp pumped dye lasers and nitrogen and excimer laser pumped dye lasers. These lasers and the associated electro-optics system, some with computer controlled, are designed and developed for the following areas of applications: 1. Industrial applications of high power carbon dioxide lasers for making of i.c. components and other materials processing purposes. Prototype operational systems have been developed. 2. Medical applications of lasers for cancer treatment using the technique of photodynamic therapy. A new and more effective treatment protocol has been proposed. 3. Agricultural applications of lasers in palm oil and palm fruit-fluorescence diagnostic studies. Fruit ripeness signature has been developed and palm oil oxidation level were investigated. 4. Development of atmospheric pollution monitoring systems using laser lidar techniques. Laboratory scale systems were developed. 5. Other applications of lasers including laser holographic and interferometric methods for the non destructive testing of materials. The activities of the group (from 1988-1990) have resulted in the submission of a patent for a laser device, publication of many research paper sin local and overseas journals and conference proceedings, completion of 1 Ph.D. dissertation and 6 M. Phil theses. Currently (1991), a total of 3 Ph.D., 6 M. Phil research programmes are involved in this research and development programme

  16. Laser Ablation for Medical Applications

    Science.gov (United States)

    Hayashi, Ken-Ichi

    Medical applications of laser are measurement, laser surgery, in-situ monitoring, and processing of medical devices. In this paper, author briefly reviews the trends of medical applications, describes some new applications, and then discuss about the future trends and problems of medical applications. At present, the domestic market of laser equipment for medical applications is nearly 1/10 of that for industrial applications, which has registered significant growth continuously. Laser surgery as a minimum invasive surgery under arthroscope is expected to decrease the pain of patients. Precise processing such as cutting and welding is suitable for manufacturing medical devices. Pulsed laser deposition has been successfully applied to the thin film coating. The corneal refractive surgery by ArF excimer laser has been widely accepted for its highly safe operation. Laser ablation for retinal implant in the visual prosthesis is one of the promising applications of laser ablation in medicine. New applications with femtosecond laser are expected in the near future.

  17. Military laser weapons: current controversies.

    Science.gov (United States)

    Seet, B; Wong, T Y

    2001-09-01

    Military laser weapons systems are becoming indispensable in most modern armies. These lasers have undergone many stages of development, and have outpaced research on eye protection measures, which continue to have inherent limitations. Eye injuries caused by military lasers are increasingly reported, leading to speculation that these would become an important cause of blinding in modern conflicts. As part of the effort to ban inhumane weapons, international laws have been passed to restrict the proliferation of such blinding weapons. However, there are controversies concerning the interpretation, implementation and effectiveness of these laws. The ophthalmic community can play a greater role in highlighting ocular morbidity from military lasers, and in preventing their further proliferation.

  18. Application of photoluminescence imaging and laser-beam-induced-current mapping in thin film solar cell characterization

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Geyuan [Iowa State Univ., Ames, IA (United States)

    2017-05-06

    My research projects are focused on application of photonics, optics and micro- fabrication technology in energy related fields. Photonic crystal fabrication research has the potential to help us generate and use light more efficiently. In order to fabricate active 3D woodpile photonic structure devices, a woodpile template is needed to enable the crystal growth process. We developed a silica woodpile template fabrication process based on two polymer transfer molding technique. A silica woodpile template is demonstrated to work with temperature up to 900 C. It provides a more economical way to explore making better 3D active woodpile photonic devices like 3D photonic light emitting diodes (LED). Optical research on solar cell testing has the potential to make our energy generation more e cient and greener. PL imaging and LBIC mapping are used to measure CdTe solar cells with different back contacts. A strong correlation between PL image defects and LBIC map defects is observed. This opens up potential application for PL imaging in fast solar cell inspection. 2D laser IV scan shows its usage in 2D parameter mapping. We show its ability to generate important information about solar cell performance locally around PL image defects.

  19. Novel oral laser applications

    Science.gov (United States)

    Yousif, A.; Strassl, M.; Beer, F.; Verhagen, L.; Wittschier, M.; Wintner, E.

    2007-03-01

    In dental hard tissue ablation, ultra-short laser pulses have proven sufficiently their potential for material ablation with negligible collateral damage providing many advantages. The absence of micro-cracks and the possibility to avoid overheating of the pulp during dental cavity preparation may be among the most important issues, the latter opening up an avenue for potential painless treatment. Beside the evident short interaction time of laser radiation with the irradiated tissue, scanning of the ultra-short pulse trains turned out to be crucial for ablating cavities of required quality and shape. Additionally, long-pulsed laser systems have demonstrated successfully their suitability for decontamination purposes. In this paper, an overview of different indications for laser application in dental therapies in both pulse regimes is presented. A special focus is set on the decontamination of dental implants in periimplantitis therapy. Having employed commercially available long pulse systems for dental applications and ultra-short 330 fs pulses, we present first results for temperature development and corresponding ablation thresholds for dental implants, as in the future more gentle implant cleaning by ultra-short laser pulses could become of interest.

  20. Laser technology and applications in gynaecology.

    Science.gov (United States)

    Adelman, M R; Tsai, L J; Tangchitnob, E P; Kahn, B S

    2013-04-01

    The term 'laser' is an acronym for Light Amplification by Stimulated Emission of Radiation. Lasers are commonly described by the emitted wavelength, which determines the colour of the light, as well as the active lasing medium. Currently, over 40 types of lasers have been developed with a wide range of both industrial and medical uses. Gas and solid-state lasers are frequently used in surgical applications, with CO2 and Ar being the most common examples of gas lasers, and the Nd:YAG and KTP:YAG being the most common examples of solid-state lasers. At present, it appears that the CO2, Nd:YAG, and KTP lasers provide alternative methods for achieving similar results, as opposed to superior results, when compared with traditional endoscopic techniques, such as cold-cutting monopolar and bipolar energy. This review focuses on the physics, tissue interaction, safety and applications of commonly used lasers in gynaecological surgery.

  1. Diode laser based light sources for biomedical applications

    DEFF Research Database (Denmark)

    Müller, André; Marschall, Sebastian; Jensen, Ole Bjarlin

    2013-01-01

    Diode lasers are by far the most efficient lasers currently available. With the ever-continuing improvement in diode laser technology, this type of laser has become increasingly attractive for a wide range of biomedical applications. Compared to the characteristics of competing laser systems, diode...... imaging. This review provides an overview of the latest development of diode laser technology and systems and their use within selected biomedical applications....

  2. Tunable lasers for waste management photochemistry applications

    International Nuclear Information System (INIS)

    Finch, F.T.

    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 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

  3. Beam current controller for laser ion source

    Science.gov (United States)

    Okamura, Masahiro

    2014-10-28

    The present invention relates to the design and use of an ion source with a rapid beam current controller for experimental and medicinal purposes. More particularly, the present invention relates to the design and use of a laser ion source with a magnetic field applied to confine a plasma flux caused by laser ablation.

  4. Dye laser principles with applications

    CERN Document Server

    Duarte, Frank J; Liao, Peter F; Kelley, Paul

    1990-01-01

    A tutorial introduction to the field of dye lasers, Dye Laser Principles also serves as an up-to-date overview for those using dye lasers as research and industrial tools. A number of the issues discussed in this book are pertinent not only to dye lasers but also to lasers in general. Most of the chapters in the book contain problem sets that expand on the material covered in the chapter.Key Features* Dye lasers are among the most versatile and successful laser sources currently available in use Offering both pulsed and continuous-wave operation and tunable from the near ultraviole

  5. Lasers: principles, applications and energetic measures; Lasers: principes, applications et mesures energetiques

    Energy Technology Data Exchange (ETDEWEB)

    Subran, C.; Sagaut, J. [Opton Laser International, 91 - Orsay (France); Lapointe, S. [Gentec Electro-Optique (Canada)

    2009-12-15

    After having recalled the principles of a laser and the properties of the laser beam, the authors describe the following different types of lasers: solid state lasers, fiber lasers, semiconductor lasers, dye lasers and gas lasers. Then, their applications are given. Very high energy lasers can reproduce the phenomenon of nuclear fusion of hydrogen atoms. (O.M.)

  6. Ultraviolet laser technology and applications

    CERN Document Server

    Elliott, David L

    1995-01-01

    Ultraviolet Laser Technology and Applications is a hands-on reference text that identifies the main areas of UV laser technology; describes how each is applied; offers clearly illustrated examples of UV opticalsystems applications; and includes technical data on optics, lasers, materials, and systems. This book is unique for its comprehensive, in-depth coverage. Each chapter deals with a different aspect of the subject, beginning with UV light itself; moving through the optics, sources, and systems; and concluding with detailed descriptions of applications in various fields.The text enables pr

  7. Industrial applications of laser; Applications industrielles du laser

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2001-07-01

    This technical dossier is a result of a collaboration between the CFE and the Power Laser club with the sustain of the French Ministry of Industry. It presents a catalogue of the industrial applications of the laser technology in France with about 80 technical files about companies using this technology in various domains such as: weapons industry, civil engineering, confection, automotive equipments, electrical equipments, medical applications, instrumentation, tools, sheet iron and steel plate industry etc.. (J.S.)

  8. Laser Beam Scintillation with Applications

    CERN Document Server

    Andrews, Larry C; Young, Cynthia

    2001-01-01

    Renewed interest in laser communication systems has sparked development of useful new analytic models. This book discusses optical scintillation and its impact on system performance in free-space optical communication and laser radar applications, with a detailed look at propagation phenomena and the role of scintillation on system behavior. Intended for practicing engineers, scientists, and students.

  9. Application of lasers in endodontics

    Science.gov (United States)

    Ertl, Thomas P.; Benthin, Hartmut; Majaron, Boris; Mueller, Gerhard J.

    1997-12-01

    Root canal treatment is still a problem in dentistry. Very often the conventional treatment fails and several treatment sessions are necessary to save the tooth from root resection or extraction. Application of lasers may help in this situation. Bacteria reduction has been demonstrated both in vitro and clinically and is either based on laser induced thermal effects or by using an ultraviolet light source. Root canal cleansing is possible by Er:YAG/YSGG-Lasers, using the hydrodynamic motion of a fluid filled in the canals. However root canal shaping using lasers is still a problem. Via falsas and fiber breakage are points of research.

  10. The application of laser plasma in ophthalmology

    International Nuclear Information System (INIS)

    He Yujiang; Luo Le; Sun Yabing

    2000-01-01

    The production and development of laser plasma are introduced, and the contribution of laser biomedicine and laser plasma technology to ophthalmology is analyzed. The latest three progresses (laser photocoagulation, photo-refractive keratotomy and laser iridectomy) of laser plasma applications in ophthalmology are presented

  11. Civilian applications of laser fusion

    International Nuclear Information System (INIS)

    Maniscalco, J.; Blink, J.; Buntzen, R.; Hovingh, J.; Meier, W.; Monsler, M.; Walker, P.

    1977-01-01

    The commercial aspects of laser fusion were evaluated in an attempt to relate the end products (neutrons and energy) to significant commercial applications. It was found that by far the largest markets and highest payoffs for laser fusion are associated with electric power production. Hence, much of this report evaluates the prospects of producing commercial electricity with laser fusion. To this end, we have described in detail a new and promising laser fusion concept--the liquid lithium waterfall reactor. In addition, we have taken the most attractive features from our laser studies and used them to compare laser fusion to other long-range sources of energy (breeder reactors and solar energy). It is our contention that all three sources of electrical energy should be developed to the point where the final selections are primarily based on economic competitiveness. The other potential applications of laser fusion (fissile fuel production, synthetic fuel production, actinide burning, and propulsion) are also discussed, and our preliminary plan for the engineering development of laser fusion is presented

  12. Civilian applications of laser fusion

    Energy Technology Data Exchange (ETDEWEB)

    Maniscalco, J.; Blink, J.; Buntzen, R.; Hovingh, J.; Meier, W.; Monsler, M.; Walker, P.

    1977-11-17

    The commercial aspects of laser fusion were evaluated in an attempt to relate the end products (neutrons and energy) to significant commercial applications. It was found that by far the largest markets and highest payoffs for laser fusion are associated with electric power production. Hence, much of this report evaluates the prospects of producing commercial electricity with laser fusion. To this end, we have described in detail a new and promising laser fusion concept--the liquid lithium waterfall reactor. In addition, we have taken the most attractive features from our laser studies and used them to compare laser fusion to other long-range sources of energy (breeder reactors and solar energy). It is our contention that all three sources of electrical energy should be developed to the point where the final selections are primarily based on economic competitiveness. The other potential applications of laser fusion (fissile fuel production, synthetic fuel production, actinide burning, and propulsion) are also discussed, and our preliminary plan for the engineering development of laser fusion is presented.

  13. Civilian applications of laser fusion

    International Nuclear Information System (INIS)

    Maniscalco, J.; Blink, J.; Buntzen, R.; Hovingh, J.; Meier, W.; Monsler, M.; Walker, P.

    1978-01-01

    The commercial aspects of laser fusion were evaluated in an attempt to relate the end products (neutrons and energy) to significant commercial applications. We have found that by far the largest markets and highest payoffs for laser fusion are associated with electric power production. Hence, much of this report evaluates the prospects of producing commercial electricity with laser fusion. To this end, we have described in detail a new and promising laser fusion concept--the liquid lithium waterfall reactor. In addition, we have taken the most attractive features from our laser fusion studies and used them to compare laser fusion to other long-range sources of energy (breeder reactors and solar energy). It is our contention that all three sources of electrical energy should be developed to the point where the final selections are primarily based on economic competitiveness. The other potential applications of laser fusion (fissile fuel production, synthetic fuel production, actinide burning, and propulsion) are also discussed, and our preliminary plan for the engineering development of laser fusion is presented

  14. Lasers and optoelectronics fundamentals, devices and applications

    CERN Document Server

    Maini, Anil K

    2013-01-01

    With emphasis on the physical and engineering principles, this book provides a comprehensive and highly accessible treatment of modern lasers and optoelectronics. Divided into four parts, it explains laser fundamentals, types of lasers, laser electronics & optoelectronics, and laser applications, covering each of the topics in their entirety, from basic fundamentals to advanced concepts. Key features include: exploration of technological and application-related aspects of lasers and optoelectronics, detailing both existing and emerging applications in industry, medical diag

  15. 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

  16. The laser principles and application techniques

    International Nuclear Information System (INIS)

    Maillet, H.

    1990-01-01

    In this book on laser applications chapter 4 is devoted to uranium isotopic separation and chapter 5 to laser inertial fusion, other topics include machining, medical applications, measurements, military applications, holography, reprography, telecommunications, compact discs, light shows and safety [fr

  17. Applications Of Laser Processing For Automotive Manufacturing In Japan

    Science.gov (United States)

    Ito, Masashi; Ueda, Katsuhiko; Takagi, Soya

    1986-11-01

    Recently in Japan, laser processing is increasingly being employed for production, so that laser cutting, laser welding and other laser material processing have begun to be used in various industries. As a result, the number of lasers sold has been increasing year by year in Japan. In the Japanese automotive industry, a number applications have been introduced in laboratories and production lines. In this paper, several current instances of such laser applications will be introduced. In the case of welding, studies have been conducted on applying laser welding to automatic transmission components, in place of electron beam welding. Another example of application, the combination of lasers and robots to form highly flexible manufacturing systems, has been adopted for trimming steel panel and plastic components.

  18. Argon laser application to endodontics

    Science.gov (United States)

    Blankenau, Richard J.; Ludlow, Marvin; Anderson, David

    1993-07-01

    The application of laser technology to endodontics has been studied for some time. At the present time several major problems are being investigated: (1) removal of infected tissues, (2) sterilization of canals, (3) obturation of canals, and (4) preservation of the vitality of supporting tissues. This list is not intended to imply other problems do not exist or have been solved, but it is a starting point. This paper reviews some of the literature that relates to laser applications to endodontics and concludes with some of the findings from our investigation.

  19. Ultrashort pulse laser technology laser sources and applications

    CERN Document Server

    Schrempel, Frank; Dausinger, Friedrich

    2016-01-01

    Ultrashort laser pulses with durations in the femtosecond range up to a few picoseconds provide a unique method for precise materials processing or medical applications. Paired with the recent developments in ultrashort pulse lasers, this technology is finding its way into various application fields. The book gives a comprehensive overview of the principles and applications of ultrashort pulse lasers, especially applied to medicine and production technology. Recent advances in laser technology are discussed in detail. This covers the development of reliable and cheap low power laser sources as well as high average power ultrashort pulse lasers for large scale manufacturing. The fundamentals of laser-matter-interaction as well as processing strategies and the required system technology are discussed for these laser sources with respect to precise materials processing. Finally, different applications within medicine, measurement technology or materials processing are highlighted.

  20. Limits of applicability of a time-of-flight ion-mass analyzer in uncovering partial currents of ions emitted by pulsed laser ion sources

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; Láska, Leoš; Rohlena, Karel; Velyhan, Andriy; Czarnecka, A.; Parys, P.; Ryc, L.; Wolowski, J.

    2010-01-01

    Roč. 165, 6-10 (2010), s. 441-450 ISSN 1042-0150 R&D Projects: GA MŠk(CZ) LC528; GA AV ČR IAA100100715 EU Projects: European Commission(XE) 228334 - LASERLAB-EUROPE Institutional research plan: CEZ:AV0Z10100523 Keywords : laser-produced plasma * time-resolved current deconvolution * ion velocity distribution * drift velocity of ions Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.660, year: 2010

  1. Laser applications in the electronics and optoelectronics industry in Japan

    Science.gov (United States)

    Washio, Kunihiko

    1999-07-01

    This paper explains current status and technological trends in laser materials processing applications in electronics and optoelectronics industry in Japan. Various laser equipment based on solid state lasers or gas lasers such as excimer lasers or CO2 lasers has been developed and applied in manufacturing electronic and optoelectronic devices to meet the strong demands for advanced device manufacturing technologies for high-performance, lightweight, low power-consumption portable digital electronic appliances, cellular mobile phones, personal computers, etc. Representative applications of solid-state lasers are, opaque and clear defects repairing of photomasks for LSIs and LCDs, trimming of thick-film chip resistors and low resistance metal resistors, laser cutting and drilling of thin films for high-pin count semiconductor CSP packages, laser patterning of thin-film amorphous silicon solar cells, and laser welding of electronic components such as hard-disk head suspensions, optical modules, miniature relays and lithium ion batteries. Compact and highly efficient diode- pumped and Q-switched solid-state lasers in second or third harmonic operation mode are now being increasingly incorporated in various laser equipment for fine material processing. Representative applications of excimer lasers are, sub-quarter micron design-rule LSI lithography and low- temperature annealing of poly-silicon TFT LCD.

  2. Ultraintense lasers and their applications

    Energy Technology Data Exchange (ETDEWEB)

    Mourou, G.A. [University of Michigan, Center for Ultrafast Optical Science, Ann Arbor, MI (United States)

    2001-10-01

    Traditional optics concerns physical phenomena in the electron-volt regime. The new frontier will address giga-electron-volt energy scales. In the last decade, lasers have undergone orders-of-magnitude jumps in peak power, with the invention of the technique of chirped pulse amplification (CPA) and the refinement of femtosecond techniques. Modern CPA lasers can produce intensities greater than 10{sup 21} W/cm{sup 2}, one million times greater than previously possible. These ultraintense lasers give researchers a tool to produce unprecedented pressures (terabars), magnetic fields (gigagauss), temperatures (10{sup 10} K), and accelerations (10{sup 25} g) with applications in fusion energy, nuclear physics, high-energy physics, astrophysics, and cosmology. (author)

  3. [Applications of lasers in dental implantology].

    Science.gov (United States)

    Mu, Yue; Li, Qian; Zhao, Ji-zhi

    2014-10-01

    With the constant progress of laser physics, medical laser technology has been widely applied in clinical practices and basic researches. In this article, we reviewed the relevant articles on the laser applications in dental implantology and concluded that lasers provides promising solutions in the treatment technology of dental implants and in the treatment of soft and hard tissue conditions.

  4. [The application of laser in endodontics].

    Science.gov (United States)

    He, W X; Liu, N N; Wang, X L; He, X Y

    2016-08-01

    Since laser was introduced in the field of medicine in 1970's, its application range has continuously expanded. The application of laser in endodontics also increased due to its safety and effectiveness in dental treatments. The majority of the laser application researches in dentistry focused on dentin hypersensitivity, removal of carious tissues, tooth preparations, pulp capping or pulpotomy, and root canal treatment. In this article, we reviewed literature on the effects of laser in the treatments of dental and pulp diseases.

  5. Space-Based Lasers for Remote Sensing Applications

    Science.gov (United States)

    Yu, Anthony W.

    2011-01-01

    There are currently three operational lidar systems orbiting the Earth, the Moon and the planet Mercury gathering scientific data and images to form a better understanding of our Earth and solar system. In this paper we will present an overview of the spacebome laser programs and offer insights into future spacebome lasers for remote sensing applications.

  6. Laser applications in endodontics: an update review.

    Science.gov (United States)

    Mohammadi, Zahed

    2009-02-01

    The search for new devices and technologies for endodontic procedures always has been challenging. Since the development of the ruby laser by Maiman in 1960 and the application of the laser for endodontics by Weichman in 1971, a variety of potential applications for lasers in endodontics have been proposed. With the development of thinner, more flexible and durable laser fibres, laser applications in endodontics have increased. Since laser devices are still relatively costly, access to them is limited. The purpose of this paper is to summarise laser applications in endodontics, including their use in pulp diagnosis, dentinal hypersensitivity, pulp capping and pulpotomy, sterilisation of root canals, root canal shaping and obturation and apicectomy. The effects of lasers on root canal walls and periodontal tissues are also reviewed.

  7. Current Status of Fractional Laser Resurfacing.

    Science.gov (United States)

    Carniol, Paul J; Hamilton, Mark M; Carniol, Eric T

    2015-01-01

    Fractional lasers were first developed based on observations of lasers designed for hair transplantation. In 2007, ablative fractional laser resurfacing was introduced. The fractionation allowed deeper tissue penetration, leading to greater tissue contraction, collagen production and tissue remodeling. Since then, fractional erbium:YAG resurfacing lasers have also been introduced. These lasers have yielded excellent results in treating photoaging, acne scarring, and dyschromia. With the adjustment of microspot density, pulse duration, number of passes, and fluence, the surgeon can adjust the treatment effects. These lasers have allowed surgeons to treat patients with higher Fitzpatrick skin types (types IV to VI) and greater individualize treatments to various facial subunits. Immunohistochemical analysis has demonstrated remodeling effects of the tissues for several months, producing longer lasting results. Adjuvant treatments are also under investigation, including concomitant face-lift, product deposition, and platelet-rich plasma. Finally, there is a short recovery time from treatment with these lasers, allowing patients to resume regular activities more quickly. Although there is a relatively high safety profile for ablative fractionated lasers, surgeons should be aware of the limitations of specific treatments and the associated risks and complications.

  8. Laser applications in thin-film photovoltaics

    OpenAIRE

    Bartlome, R.; Strahm, B.; Sinquin, Y.; Feltrin, A.; Ballif, C.

    2009-01-01

    We review laser applications in thin-film photovoltaics (thin-film Si, CdTe, and Cu(In,Ga)Se2 solar cells). Lasers are applied in this growing field to manufacture modules, to monitor Si deposition processes, and to characterize opto-electrical properties of thin films. Unlike traditional panels based on crystalline silicon wafers, the individual cells of a thin-film photovoltaic module can be serially interconnected by laser scribing during fabrication. Laser scribing applications are descri...

  9. Droplet lasers: a review of current progress

    Science.gov (United States)

    McGloin, D.

    2017-05-01

    It is perhaps surprising that something as fragile as a microscopic droplet could possibly form a laser. In this article we will review some of the underpinning physics as to how this might be possible, and then examine the state of the art in the field. The technology to create and manipulate droplets will be examined, as will the different classes of droplet lasers. We discuss the rapidly developing fields of droplet biolasers, liquid crystal laser droplets and explore how droplet lasers could give rise to new bio and chemical sensing and analysis. The challenges that droplet lasers face in becoming robust devices, either as sensors or as photonic components in the lab on chip devices, is assessed.

  10. Application of lasers in laparoscopy

    Science.gov (United States)

    Stanowski, Edward; Domaniecki, Janusz

    1995-03-01

    The application of laser light and laparoscopy attenuates operative trauma owing to the use of small incisions for introducing the trochars necessary for conveying the surgical instruments and fiber optics which allow for precise cutting and coagulation of small vessels under control of the image on a TV monitor. The present, most remarkable development of laparoscopic surgery is due to the fascination of physicians and patients by this procedure. The method enables the physician to operate with great precision and to take advantage of the most recent attainments of electronics and laser technique, as well as of his own ability. The patients profit by attenuation of postoperative pain, limitation of the probability of infection, reduced blood loss, decreased number of postoperative complications, shortening of the hospitalization period, and rapid return to physical fitness and work.

  11. Therapeutic applications of lasers in urology: an update.

    Science.gov (United States)

    Fried, Nathaniel M

    2006-01-01

    There has been renewed interest in the use of lasers for minimally invasive treatment of urologic diseases in recent years. The introduction of more compact, higher power, less expensive and more user-friendly solid-state lasers, such as the holmium:yttrium-aluminum-garnet (YAG), frequency-doubled neodymium:YAG and diode lasers has made the technology more attractive for clinical use. The availability of small, flexible, biocompatible, inexpensive and disposable silica optical fiber delivery systems for use in flexible endoscopes has also promoted the development of new laser procedures. The holmium:YAG laser is currently the workhorse laser in urology since it can be used for multiple soft- and hard-tissue applications, including laser lithotripsy, benign prostate hyperplasia, bladder tumors and strictures. More recently, higher power potassium-titanyl-phosphate lasers have been introduced and show promise for the treatment of benign prostatic hyperplasia. On the horizon, newer and more effective photosensitizing drugs are being tested for potential use in photodynamic therapy of bladder and prostate cancer. Additionally, new experimental lasers such as the erbium:YAG, Thulium and Thulium fiber lasers, may provide more precise incision of soft tissues, more efficient laser lithotripsy and more rapid prostate ablation. This review provides an update on the most important new clinical and experimental therapeutic applications of lasers in urology over the past 5 years.

  12. Therapeutic application of lasers in ophthalmology

    International Nuclear Information System (INIS)

    Misiuk-Hojlo, M.; Krzyzanowska-Berkowska, P.; Hill-Bator, A.

    2007-01-01

    Lasers have found application in diverse branches of medicine. In ophthalmology, laser technology has various therapeutic and diagnostic applications. The purpose of this article is to review the major therapeutic applications of lasers in different eye disorders. The effects of lasers on biological tissues and different laser techniques as well as the indications for laser therapy in various parts of the eye are discussed. Lasers are used to treat glaucoma and many vascular disorders of the retina. Laser treatment may be useful in preventing the development of neovascularization in diabetic retinopathy, BRVO, or CRVO. Laser techniques are also available for the treatment of the exudative form of age-related macular degeneration (AMD) and some malignant and benign intraocular tumors and in retina abnormalities which predispose to rhegmatogenous retinal detachment. Corneal laser surgery is the most frequently applied laser procedure in ophthalmology. PRK, LASIK, and LASEK are used to correct errors in vision such as myopia, hyperopia, and astigmatism. Laser photocoagulation is also helpful in cataract surgery. Nowadays, lasers have become so universal that it is difficult to imagine ophthalmology without them. We are still witnessing rapid advances in the development of laser techniques, especially in plastic surgery, cataract extraction, and ocular imaging. (authors)

  13. Industrial application of high power disk lasers

    Science.gov (United States)

    Brockmann, Rüdiger; Havrilla, David

    2008-02-01

    Laser welding has become one of the fastest growing areas for industrial laser applications. The increasing cost effectiveness of the laser process is enabled by the development of new highly efficient laser sources, such as the Disk laser, coupled with decreasing cost per Watt. TRUMPF introduced the Disk laser several years ago, and today it has become the most reliable laser tool on the market. The excellent beam quality and output powers of up to 10 kW enable its application in the automotive industry as well as in the range of thick plate welding, such as heavy construction and ship building. This serves as an overview of the most recent developments on the TRUMPF Disk laser and its industrial applications like cutting, welding, remote welding and hybrid welding, too. The future prospects regarding increased power and even further improved productivity and economics are presented.

  14. High-power green diode laser systems for biomedical applications

    DEFF Research Database (Denmark)

    Müller, André

    spectroscopy and imaging, and fluorescence measurements. A major challenge in diode laser technology is to obtain high-power laser emission at wavelengths green spectral range is of high importance, for example, in dermatology or for direct pumping of ultrashort pulsed lasers...... in conjunction with optical coherence tomography, two-photon microscopy or coherent anti-Stokes Raman scattering microscopy. In order to provide high-power green diode laser emission, nonlinear frequency conversion of state-of-the-art near-infrared diode lasers represents a necessary means. However, the obtained...... output power of frequency doubled single emitters is limited by thermal effects potentially resulting in laser degradation and failure. In this work new concepts for power scaling of visible diode laser systems are introduced that help to overcome current limitations and enhance the application potential...

  15. Abstracts of 2. International conference on lasers and their applications

    International Nuclear Information System (INIS)

    1993-01-01

    The following topics are presented at 2. international conference on lasers and their applications in Iran: laser principle and technology, laser applications in spectroscopy; nonlinear optics; industry; medicine; and laser related techniques

  16. Paediatric laser dentistry. Part 4: Soft tissue laser applications.

    Science.gov (United States)

    Olivi, G; Caprioglio, C; Olivi, M; Genovese, M D

    2017-12-01

    Lasers can provide effective soft tissues applications in children. All the wavelengths produce incision and vaporisation of oral tissues, together with a high bactericidal effect. The haemosthatic effect varys according to the wavelength used, and the choice of a visibile, near, medium or far infrared laser allows a better interaction with specific targets, gingiva, mucosa, frenum, or oral pathology.

  17. Evolution and applications of lasers in oral and maxillofacial surgery

    OpenAIRE

    Luke Nandu Kale; Janardan Bhagwat Garde; Swapnil Shivdas Garde; Preetika Gupta

    2017-01-01

    With the advent of new and developing technology into the field of dentistry, it becomes increasingly important for dentists to become familiar with these developing techniques. The use of lasers in oral and maxillofacial surgery has seen a substantial increase in both, applications of lasers for different techniques, and also the number of surgeons opting to use them on a regular basis. This article serves to update practitioners on the development and current applications of these modern to...

  18. Programmable current source for diode lasers stabilized optical fiber

    International Nuclear Information System (INIS)

    Gomez, J.; Camas, J.; Garcia, L.

    2012-01-01

    In this paper, we present the electronic design of a programmable stabilized current source. User can access to the source through a password, which, it has a database with the current and voltage operating points. This source was successfully used as current source in laser diode in optical fiber sensors. Variations in the laser current were carried out by a monitoring system and a control of the Direct Current (DC), which flowing through a How land source with amplifier. The laser current can be stabilized with an error percent of ± 1 μA from the threshold current (Ith) to its maximum operation current (Imax) in DC mode. The proposed design is reliable, cheap, and its output signal of stabilized current has high quality. (Author)

  19. Review of soft x-ray lasers and their applications

    International Nuclear Information System (INIS)

    Skinner, C.H.

    1991-03-01

    The emerging technology of soft x-ray lasers is in a transition phase between the first laboratory demonstrations of gain and the acceptance of soft x-ray lasers as practical tools for novel applications. Current research is focused on several fronts. The operational wavelength range has been extended to the ''water window'', important for applications in the life sciences. Gain has also been generated with substantially simpler technology (such as a 6J laser) and this augurs well for the commercially availability in the near future of soft x-ray lasers for a variety of applications. Advanced soft x-ray laser concepts are being developed from investigations into ultra-high intensity laser/matter interactions. The first paper a brief historical perspective of x-ray microscopy and holography have begun. In this paper a brief historical perspective of x-ray laser development will be followed by a review of recent advances in recombination, collisional and photo-pumped systems and applications. A summary of current gain-length performance achieved in laboratories worldwide is presented. Near term prospects for applications to novel fields are discussed. 81 refs., 9 figs., 1 tab

  20. Clinical applications of laser scanning cytometry.

    Science.gov (United States)

    Tárnok, Attila; Gerstner, Andreas O H

    2002-06-15

    This study reviews existing and potential clinical applications of laser scanning cytometry (LSC) and outlines possible future developments. LSC provides a technology for solid phase cytometry. Fluorochrome-labeled specimens are immobilized on microscopic slides that are placed on a conventional epifluorescence microscope and analyzed by one or two lasers. Data comparable to flow cytometry are generated. In addition, the position of each event is recorded, a feature that allows relocalization and visualization of each measured event. The major advantage of LSC compared with other cytometric methods is the combination of two features: (a) the minimal clinical sample volume needed and (b) the connection of fluorescence data and morphological information for the measured event. Since the introduction of LSC, numerous methods have been established for the analysis of cells, cellular compartments, and tissues. Although most cytometric methods use only two or three colors, the characterization of specimens with up to five fluorochromes is possible. Most clinical applications have been designed to determine ploidy and immunophenotype; other applications include analyses of tissue biopsies and sections, fluorescence in situ hybridization, and the combination of vital and nonvital information on a single-cell basis. With the currently available assays, LSC has proven its wide spectrum of clinical applicability in slide-based cytometry and can be introduced as a standard technology in multiple clinical settings. Copyright 2002 Wiley-Liss, Inc.

  1. Short pulse laser systems for biomedical applications

    CERN Document Server

    Mitra, Kunal

    2017-01-01

    This book presents practical information on the clinical applications of short pulse laser systems and the techniques for optimizing these applications in a manner that will be relevant to a broad audience, including engineering and medical students as well as researchers, clinicians, and technicians. Short pulse laser systems are useful for both subsurface tissue imaging and laser induced thermal therapy (LITT), which hold great promise in cancer diagnostics and treatment. Such laser systems may be used alone or in combination with optically active nanoparticles specifically administered to the tissues of interest for enhanced contrast in imaging and precise heating during LITT. Mathematical and computational models of short pulse laser-tissue interactions that consider the transient radiative transport equation coupled with a bio-heat equation considering the initial transients of laser heating were developed to analyze the laser-tissue interaction during imaging and therapy. Experiments were first performe...

  2. Some applications on laser material processing

    International Nuclear Information System (INIS)

    Oros, C.

    2005-01-01

    An overview of the state-of-the-art in laser material processing for a large types of lasers from IR (CO 2 laser, NdYAG laser) to UV (excimer laser) and different kinds of materials (metals, dielectrics) is given. Laser radiation has found a wide range of applications as machining tool for various kinds of materials processing. The machining geometry, the work piece geometry, the material properties and economic productivity claim for customized systems with special design for beam guiding, shaping and delivery in order to fully utilize the laser radiation for surface processing with optimum efficiency, maximum processing speed and high processing quality. The laser-material interaction involves complex processes of heating, melting, vaporization, ejection of atoms, ions, and molecules, shock waves, plasma initiation and plasma expansion. The interaction is dependent on the laser beam parameters (pulse duration, energy and wavelength), the solid target properties and the surrounding environments condition. Experimental results for laser surface melting and laser ablation are given. Also, assuming the applicability of a one dimensional model for short pulses used, and restricting condition to single-pulse exposure, the temperature rise on the target was calculated taking account of the finite optical absorption depth and pulse duration of the laser

  3. Laser technology and applications 2012: a preview

    Science.gov (United States)

    Gajda, Jerzy; Romaniuk, Ryszard S.

    The research and technical achievements in the area of lasers are summarized every three years by the National Symposium on Laser Technology held in the Baltic See Resort Świnoujście near Szczecin, Poland. The paper presents a preview of the symposium works to be shown and debated during this key event in September 2012. There are shown development tendencies of laser materials and technologies and laser associated branches of optoelectronics in this country, including the efforts of academia, governmental institutes, research businesses and industry. The second branch of the symposium works are laser applications, where the laser systems operators and laser users present their achievements. Topical tracks of the meeting are presented, as well as the keynote and invited subjects delivered by key representatives of the laser industry.

  4. The Texas petawatt laser and current experiments

    International Nuclear Information System (INIS)

    Martinez, Mikael; Bang, Woosuk; Dyer, Gilliss; Wang Xiaoming; Gaul, Erhard; Borger, Teddy; Ringuette, Martin; Spinks, Michael; Quevedo, Hernan; Bernstein, Aaron; Donovan, Michael; Ditmire, Todd

    2012-01-01

    The Texas Petawatt Laser is operational with experimental campaigns executed in both F/40 and F3 target chambers. Recent improvements have resulted in intensities of >2×10 21 W/cm 2 on target. Experimental highlights include, accelerated electron energies of >2 GeV, DD fusion ion temperatures >25 keV and isochorically heated solids to 10-50 eV.

  5. The Texas petawatt laser and current experiments

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Mikael; Bang, Woosuk; Dyer, Gilliss; Wang Xiaoming; Gaul, Erhard; Borger, Teddy; Ringuette, Martin; Spinks, Michael; Quevedo, Hernan; Bernstein, Aaron; Donovan, Michael; Ditmire, Todd [Center for High Energy Density Science, University of Texas at Austin 1 University Station Austin, TX 78712 (United States); Laser Plasma Acceleration Group, Department of Physics, University of Texas at Austin 1 University Station Austin, TX 78712 (United States); Center for High Energy Density Science, University of Texas at Austin 1 University Station Austin, TX 78712 (United States)

    2012-12-21

    The Texas Petawatt Laser is operational with experimental campaigns executed in both F/40 and F3 target chambers. Recent improvements have resulted in intensities of >2 Multiplication-Sign 10{sup 21} W/cm{sup 2} on target. Experimental highlights include, accelerated electron energies of >2 GeV, DD fusion ion temperatures >25 keV and isochorically heated solids to 10-50 eV.

  6. The Texas petawatt laser and current experiments

    Science.gov (United States)

    Martinez, Mikael; Bang, Woosuk; Dyer, Gilliss; Wang, Xiaoming; Gaul, Erhard; Borger, Teddy; Ringuette, Martin; Spinks, Michael; Quevedo, Hernan; Bernstein, Aaron; Donovan, Michael; Ditmire, Todd

    2012-12-01

    The Texas Petawatt Laser is operational with experimental campaigns executed in both F/40 and F3 target chambers. Recent improvements have resulted in intensities of >2×1021 W/cm2 on target. Experimental highlights include, accelerated electron energies of >2 GeV, DD fusion ion temperatures >25 keV and isochorically heated solids to 10-50 eV.

  7. Laser technology in biomimetics basics and applications

    CERN Document Server

    Belegratis, Maria

    2013-01-01

    Lasers are progressively more used as versatile tools for fabrication purposes. The wide range of available powers, wavelengths, operation modes, repetition rates etc. facilitate the processing of a large spectrum of materials at exceptional precision and quality. Hence, manifold methods were established in the past and novel methods are continuously under development. Biomimetics, the translation from nature-inspired principles to technical applications, is strongly multidisciplinary. This field offers intrinsically a wide scope of applications for laser based methods regarding structuring and modification of materials. This book is dedicated to laser fabrication methods in biomimetics. It introduces both, a laser technology as well as an application focused approach.  The book covers the most important laser lithographic methods and various biomimetics application scenarios ranging from coatings and biotechnology to construction, medical applications and photonics.

  8. Safe laser application requires more than laser safety

    Science.gov (United States)

    Frevel, A.; Steffensen, B.; Vassie, L.

    1995-02-01

    An overview is presented concerning aspects of laser safety in European industrial laser use. Surveys indicate that there is a large variation in the safety strategies amongst industrial laser users. Some key problem areas are highlighted. Emission of hazardous substances is a major problem for users of laser material processing systems where the majority of the particulate is of a sub-micrometre size, presenting a respiratory hazard. Studies show that in many cases emissions are not frequently monitored in factories and uncertainty exists over the hazards. Operators of laser machines do not receive adequate job training or safety training. The problem is compounded by a plethora of regulations and standards which are difficult to interpret and implement, and inspectors who are not conversant with the technology or the issues. A case is demonstrated for a more integrated approach to laser safety, taking into account the development of laser applications, organizational and personnel development, in addition to environmental and occupational health and safety aspects. It is necessary to achieve a harmonization between these elements in any organization involved in laser technology. This might be achieved through establishing technology transfer centres in laser technology.

  9. Femtosecond lasers in ophthalmology: clinical applications in anterior segment surgery

    Science.gov (United States)

    Juhasz, Tibor; Nagy, Zoltan; Sarayba, Melvin; Kurtz, Ronald M.

    2010-02-01

    The human eye is a favored target for laser surgery due to its accessibility via the optically transparent ocular tissue. Femtosecond lasers with confined tissue effects and minimized collateral tissue damage are primary candidates for high precision intraocular surgery. The advent of compact diode-pumped femtosecond lasers, coupled with computer controlled beam delivery devices, enabled the development of high precision femtosecond laser for ophthalmic surgery. In this article, anterior segment femtosecond laser applications currently in clinical practice and investigation are reviewed. Corneal procedures evolved first and remain dominant due to easy targeting referenced from a contact surface, such as applanation lenses placed on the eye. Adding a high precision imaging technique, such as optical coherence tomography (OCT), can enable accurate targeting of tissue beyond the cornea, such as the crystalline lens. Initial clinical results of femtosecond laser cataract surgery are discussed in detail in the latter portion part of the article.

  10. Power blue and green laser diodes and their applications

    Science.gov (United States)

    Hager, Thomas; Strauß, Uwe; Eichler, Christoph; Vierheilig, Clemens; Tautz, Sönke; Brüderl, Georg; Stojetz, Bernhard; Wurm, Teresa; Avramescu, Adrian; Somers, André; Ristic, Jelena; Gerhard, Sven; Lell, Alfred; Morgott, Stefan; Mehl, Oliver

    2013-03-01

    InGaN based green laser diodes with output powers up to 50mW are now well established for variety of applications ranging from leveling to special lighting effects and mobile projection of 12lm brightness. In future the highest market potential for visible single mode profile lasers might be laser projection of 20lm. Therefore direct green single-mode laser diodes with higher power are required. We found that self heating was the limiting factor for higher current operation. We present power-current characteristics of improved R and D samples with up to 200mW in cw-operation. An optical output power of 100mW is reached at 215mA, a current level which is suitable for long term operation. Blue InGaN laser diodes are also the ideal source for phosphor based generation of green light sources of high luminance. We present a light engine based on LARP (Laser Activated Remote Phosphor) which can be used in business projectors of several thousand lumens on screen. We discuss the advantages of a laser based systems in comparison with LED light engines. LARP requires highly efficient blue power laser diodes with output power above 1W. Future market penetration of LARP will require lower costs. Therefore we studied new designs for higher powers levels. R and D chips with power-current characteristics up to 4W in continuous wave operation on C-mount at 25°C are presented.

  11. Fiber lasers and their applications [Invited].

    Science.gov (United States)

    Shi, Wei; Fang, Qiang; Zhu, Xiushan; Norwood, R A; Peyghambarian, N

    2014-10-01

    Fiber lasers have seen progressive developments in terms of spectral coverage and linewidth, output power, pulse energy, and ultrashort pulse width since the first demonstration of a glass fiber laser in 1964. Their applications have extended into a variety of fields accordingly. In this paper, the milestones of glass fiber laser development are briefly reviewed and recent advances of high-power continuous wave, Q-switched, mode-locked, and single-frequency fiber lasers in the 1, 1.5, 2, and 3 μm regions and their applications in such areas as industry, medicine, research, defense, and security are addressed in detail.

  12. Integrated Applications with Laser Technology

    Directory of Open Access Journals (Sweden)

    Octavian DOSPINESCU

    2013-01-01

    Full Text Available The introduction of new materials as Power Point presentations are the most convenient way of teaching a course or to display a scientific paper. In order to support this function, most schools, universities, institutions, are equipped with projectors and computers. For controlling the presentation of the materials, the persons that are in charge with the presentation use, in most cases, both the keyboard of the computer as well as the mouse for the slides, thing that burdens, in a way, the direct communication (face to face with the audience. Of course, the invention of the wireless mouse allowed a sort of freedom in controlling from the distance the digital materials. Although there seems to appear a certain impediment: in order to be used, the mouse requires to be placed on a flat surface. This article aims at creating a new application prototype that will manipulate, only through the means of a light-beam instrument (laser fascicle, both the actions of the mouse as well as some of the elements offered by the keyboard on a certain application or presentation. The light fascicle will be „connected” to a calculus system only through the images that were captured by a simple webcam.

  13. Laser-plasma interactions and applications

    CERN Document Server

    Neely, David; Bingham, Robert; Jaroszynski, Dino

    2013-01-01

    Laser-Plasma Interactions and Applications covers the fundamental and applied aspects of high power laser-plasma physics. With an internationally renowned team of authors, the book broadens the knowledge of young researchers working in high power laser-plasma science by providing them with a thorough pedagogical grounding in the interaction of laser radiation with matter, laser-plasma accelerators, and inertial confinement fusion. The text is organised such that the theoretical foundations of the subject are discussed first, in Part I. In Part II, topics in the area of high energy density physics are covered. Parts III and IV deal with the applications to inertial confinement fusion and as a driver of particle and radiation sources, respectively. Finally, Part V describes the principle diagnostic, targetry, and computational approaches used in the field. This book is designed to give students a thorough foundation in the fundamental physics of laser-plasma interactions. It will also provide readers with knowl...

  14. Laser robot for nuclear applications

    International Nuclear Information System (INIS)

    Geffroy, J.; Beaucourt, P. de; Noel, J.P.; Martinez, J.M.; Basire, A.; Mergy, M.

    1986-06-01

    Laser beam machining is developed by the CEA because the focused beam can cut metallic structures without mechanical efforts which is very interesting in a hot cell. The laser robot, called POLYAS, with 5 degrees of freedom is constituted by series of hollow structure in light alloys with mirrors in articulation for transmission of the beam of a power CO 2 laser, placed outside the active zone. The robot is controlled by a microcomputer. Technical characteristics are given [fr

  15. Laser applications in nuclear power plants

    Indian Academy of Sciences (India)

    2014-01-09

    Jan 9, 2014 ... Abstract. This paper reports the state of the art of using a solid-state Nd:YAG laser for material processing applications such as cutting, welding and drilling of several components of operational nuclear reactors in radioactive environment. We have demonstrated several advantages of laser- based material ...

  16. Application of Laser in Oral Surgery

    Science.gov (United States)

    Asnaashari, Mohammad; Zadsirjan, Saeede

    2014-01-01

    In this review collected from the literature on usage of laser in oral minor surgery based on a Medline search in the time period between the years: 2008 and 2013, the most current evidence on laser-assisted oral minor surgery is going to be surveyed. PMID:25653807

  17. GAS LASERS FOR STRONG-FIELD APPLICATIONS.

    Energy Technology Data Exchange (ETDEWEB)

    POGORELSKY,I.V.

    2004-09-15

    Atomic-, molecular- and excimer-gas lasers employ variety of pumping schemes including electric discharge, optical, or chemical reactions and cover a broad spectral range from UV to far-IR. Several types of gas lasers can produce multi-kilojoule pulses and kilowatts of average power. Among them, excimer- and high-pressure molecular lasers have sufficient bandwidth for generating pico- and femtosecond pulses. Projects are underway and prospects are opening up to bring ultrafast gas laser technology to the front lines of advanced accelerator applications.

  18. Ocean Current Retrievals and Applications

    Science.gov (United States)

    Johannessen, J. A.; Holt, B.; Collard, F.; Kudryavtsev, V.; Romeiser, R.; Mouche, A.

    2013-03-01

    Since the SEASAT mission in 1978, spaceborne synthetic aperture radar (SAR) images of ocean scenes have been used successfully for a variety of applications including mesoscale current features. However, although the SAR image expressions frequently manifest presence of frontal boundaries and eddies it is not straightforward to retrieve quantitative estimates from these expressions. To compensate for this limitation forward models, in which a prescribed surface current field as well as sea surface temperature and wind field are invoked, have regularly been used to simulate the SAR image expressions (Kudryavtsev et al., 2005). On the other hand, technology progress in this decade has enabled overcoming this shortcoming to some extent. The split-antenna mode of TerraSAR-X permits an acquisition of two SAR images with a short time lag for along-track interferometry (Romeiser and Runge, 2007; Romeiser et al., 2010). Additionally advanced processing of conventional SAR raw data, demonstrated with ENVISAT ASAR data, permits velocity retrievals at a reduced spatial resolution even with a single antenna (Chapron et al., 2005). Moreover, in a recent paper by Kudryavtsev et al., (2012) the use of sensor synergy has shown great potential for mapping of intense cross-frontal dynamics and vertical motions at the mesoscale to sub-mesoscale. Based on such a synergetic approach combining SST, sun-glitter brightness and radar backscatter anomalies, these studies have demonstrated the ability to obtain consistent and quantitative determination of the location and intensity of the surface current convergence/divergence connected with upwelling/downwelling along frontal zones and eddies. These methodologies and their inherent advantages and limitations are further addressed in this paper.

  19. Femtosecond lasers for countermeasure applications

    NARCIS (Netherlands)

    Franssen, G.C.; Schleijpen, H.M.A.; Heuvel, J.C. van den; Buersing, H.; Eberle, B.; Walter, D.

    2009-01-01

    In recent years, much advance in the field of high-power femtosecond laser technology has been made. The high pulse power of femtosecond laser systems leads to various interesting phenomena, such as a very high power density and the formation of a plasma in the propagation medium, which is usually

  20. Laser applications in thin-film photovoltaics

    Science.gov (United States)

    Bartlome, R.; Strahm, B.; Sinquin, Y.; Feltrin, A.; Ballif, C.

    2010-08-01

    We review laser applications in thin-film photovoltaics (thin-film Si, CdTe, and Cu(In,Ga)Se2 solar cells). Lasers are applied in this growing field to manufacture modules, to monitor Si deposition processes, and to characterize opto-electrical properties of thin films. Unlike traditional panels based on crystalline silicon wafers, the individual cells of a thin-film photovoltaic module can be serially interconnected by laser scribing during fabrication. Laser scribing applications are described in detail, while other laser-based fabrication processes, such as laser-induced crystallization and pulsed laser deposition, are briefly reviewed. Lasers are also integrated into various diagnostic tools to analyze the composition of chemical vapors during deposition of Si thin films. Silane (SiH4), silane radicals (SiH3, SiH2, SiH, Si), and Si nanoparticles have all been monitored inside chemical vapor deposition systems. Finally, we review various thin-film characterization methods, in which lasers are implemented.

  1. Evolution and applications of lasers in oral and maxillofacial surgery

    Directory of Open Access Journals (Sweden)

    Luke Nandu Kale

    2017-01-01

    Full Text Available With the advent of new and developing technology into the field of dentistry, it becomes increasingly important for dentists to become familiar with these developing techniques. The use of lasers in oral and maxillofacial surgery has seen a substantial increase in both, applications of lasers for different techniques, and also the number of surgeons opting to use them on a regular basis. This article serves to update practitioners on the development and current applications of these modern tools in regular practice so as to efficiently perform dental treatment and minimize complications associated with conventional techniques. The authors have reviewed articles on the subject from PubMed, Science Direct, and relevant textbooks so as to compile an accurate history of the evolution of lasers, its introduction to the field of dentistry and also its current applications in the field of oral and maxillofacial surgery.

  2. High temperature semiconductor diode laser pumps for high energy laser applications

    Science.gov (United States)

    Campbell, Jenna; Semenic, Tadej; Guinn, Keith; Leisher, Paul O.; Bhunia, Avijit; Mashanovitch, Milan; Renner, Daniel

    2018-02-01

    Existing thermal management technologies for diode laser pumps place a significant load on the size, weight and power consumption of High Power Solid State and Fiber Laser systems, thus making current laser systems very large, heavy, and inefficient in many important practical applications. To mitigate this thermal management burden, it is desirable for diode pumps to operate efficiently at high heat sink temperatures. In this work, we have developed a scalable cooling architecture, based on jet-impingement technology with industrial coolant, for efficient cooling of diode laser bars. We have demonstrated 60% electrical-to-optical efficiency from a 9xx nm two-bar laser stack operating with propylene-glycolwater coolant, at 50 °C coolant temperature. To our knowledge, this is the highest efficiency achieved from a diode stack using 50 °C industrial fluid coolant. The output power is greater than 100 W per bar. Stacks with additional laser bars are currently in development, as this cooler architecture is scalable to a 1 kW system. This work will enable compact and robust fiber-coupled diode pump modules for high energy laser applications.

  3. Application of Laser Irradiation for Restorative Treatments

    Science.gov (United States)

    Davoudi, Amin; Sanei, Maryam; Badrian, Hamid

    2016-01-01

    Nowadays, lasers are widely used in many fields of medicine. Also, they can be applied at many branches of dental practice such as diagnosis, preventive procedures, restorative treatments, and endodontic therapies. Procedures like caries removal, re-mineralization, and vital pulp therapy are the most noticeable effects of laser irradiation which has gained much attention among clinicians. With controlled and appropriate wavelength, they can help stimulating dentinogenesis, controlling pulpal hemorrhage, sterilization, healing of collagenic proteins, formation of a fibrous matrix, and inducing hard tissue barrier. Nevertheless, there are many controversies in literatures regarding their effects on the quality of bonded restorations. It hampered a wide application of lasers in some aspects of restorative dentistry and requirements to identify the best way to use this technology. The aim of this mini review is to explain special characteristics of laser therapy and to introduce the possible applications of laser devices for dental purposes. PMID:27990188

  4. Laser application for hypertrophic rhinitis

    Science.gov (United States)

    Inouye, Tetsuzo; Tanabe, Tetsuya; Nakanoboh, Manabu; Ogura, Masami

    1995-05-01

    The CO2 and KTP/532 lasers have been used in the treatment of an allergic and hypertrophic rhinitis for the past several years. As we know, the laser enables a surgeon to perform the operation with minimum hemorrhage and minimized pain, during and after the procedure. Additionally many of these operations can be performed under local anesthesia instead of general anesthesia, on an outpatient basis. The laser is used to irradiate the mucous membranes of the inferior turbinates. Vaporization and cutting is easily done. Post operative management of the local operated area is easy. The advantages of laser surgery over regular surgical techniques are supreme for intranasal operations when performed under local anesthesia.

  5. High-intensity laser application in Orthodontics.

    Science.gov (United States)

    Sant'Anna, Eduardo Franzotti; Araújo, Mônica Tirre de Souza; Nojima, Lincoln Issamu; Cunha, Amanda Carneiro da; Silveira, Bruno Lopes da; Marquezan, Mariana

    2017-01-01

    In dental practice, low-level laser therapy (LLLT) and high-intensity laser therapy (HILT) are mainly used for dental surgery and biostimulation therapy. Within the Orthodontic specialty, while LLLT has been widely used to treat pain associated with orthodontic movement, accelerate bone regeneration after rapid maxillary expansion, and enhance orthodontic tooth movement, HILT, in turn, has been seen as an alternative for addressing soft tissue complications associated to orthodontic treatment. The aim of this study is to discuss HILT applications in orthodontic treatment. This study describes the use of HILT in surgical treatments such as gingivectomy, ulotomy, ulectomy, fiberotomy, labial and lingual frenectomies, as well as hard tissue and other dental restorative materials applications. Despite the many applications for lasers in Orthodontics, they are still underused by Brazilian practitioners. However, it is quite likely that this demand will increase over the next years - following the trend in the USA, where laser therapies are more widely used.

  6. Fulas: high energy laser source for future lidar applications

    Science.gov (United States)

    Hahn, S.; Weimer, P.; Wuehrer, Christian; Klein, J.; Luttmann, J.; Plum, H. D.

    2017-11-01

    For atmospheric LIDAR instruments in space, a manifold of scientific applications exists. But due to the lack of high energy laser sources providing the performance, reliability and lifetime necessary to operate such instruments in space, realization is currently seen as still very critical in the community.

  7. Solid state laser systems for space application

    Science.gov (United States)

    Kay, Richard B.

    1994-01-01

    Since the last report several things have happened to effect the research effort. In laser metrology, measurements using Michelson type interferometers with an FM modulated diode laser source have been performed. The discrete Fourier transform technique has been implemented. Problems associated with this technique as well as the overall FM scheme were identified. The accuracy of the technique is not at the level we would expect at this point. We are now investigating the effect of various types of noise on the accuracy as well as making changes to the system. One problem can be addressed by modifying the original optical layout. Our research effort was also expanded to include the assembly and testing of a diode pumped\\Nd:YAG laser pumped\\Ti sapphire laser for possible use in sounding rocket applications. At this stage, the diode pumped Nd:YAG laser has been assembled and made operational.

  8. Laser measurement technology fundamentals and applications

    CERN Document Server

    Donges, Axel

    2015-01-01

    Laser measurement technology has evolved in the last years in a versatile and reflationary way. Today, its methods are indispensable for research and development activities as well as for production technology. Every physicist and engineer should therefore gain a working knowledge of laser measurement technology. This book closes the gap of existing textbooks. It introduces in a comprehensible presentation laser measurement technology in all its aspects. Numerous figures, graphs and tables allow for a fast access into the matter. In the first part of the book the important physical and optical basics are described being necessary to understand laser measurement technology. In the second part technically significant measuring methods are explained and application examples are presented. Target groups of this textbook are students of natural and engineering sciences as well as working physicists and engineers, who are interested to make themselves familiar with laser measurement technology and its fascinating p...

  9. High-power optics lasers and applications

    CERN Document Server

    Apollonov, Victor V

    2015-01-01

    This book covers the basics, realization and materials for high power laser systems and high power radiation interaction with  matter. The physical and technical fundamentals of high intensity laser optics and adaptive optics and the related physical processes in high intensity laser systems are explained. A main question discussed is: What is power optics? In what way is it different from ordinary optics widely used in cameras, motion-picture projectors, i.e., for everyday use? An undesirable consequence of the thermal deformation of optical elements and surfaces was discovered during studies of the interaction with powerful incident laser radiation. The requirements to the fabrication, performance and quality of optical elements employed within systems for most practical applications are also covered. The high-power laser performance is generally governed by the following: (i) the absorption of incident optical radiation (governed primarily by various absorption mechanisms), (ii) followed by a temperature ...

  10. Development of laser heated high current DC electron gun

    International Nuclear Information System (INIS)

    Banerjee, Srutarshi; Bhattacharjee, Dhruva; Kandaswamy, E.; Ghodke, S.R.; Tiwari, Rajnish; Bakhtsingh, R.I.

    2015-01-01

    The paper deals with the development of a Laser heated cathode for Electron Accelerator. The electron gun is meant for Megawatt-class DC Accelerator for Electron Beam Flue Gas Treatment applications. Conventionally, LaB 6 cathode is indirectly heated by tungsten filaments whereas in the newly proposed gun, Laser is utilized for heating. A Nd:YAG Laser is used to heat the LaB 6 cathode to emission temperatures. The characterization of cathode heating at various Laser powers has been carried out. In initial trials, it has been observed that with 125 W of Laser power, the LaB 6 pellet was heated to 1315 ° C. Based on these experimental results, an electron gun rated for 30 kV, 350 mA CW has been designed. The optimization of gun electrode geometry has been done using CST Particle Studio in order to tune the various electron gun parameters. The beam diameter obtained in simulation is 8 mm at 100 mm from the LaB 6 cathode. The perveance obtained is 7.1 x 10 -8 A/V 3/2 . The Laser heated cathode has the advantages of eliminating the magnetic field effects of filament on the electron beam, electrical isolation needed for gun filament power supplies and better electron beam emittances. (author)

  11. Spin current generation by ultrafast laser pulses in ferromagnetic nickel films

    Science.gov (United States)

    Hurst, Jérôme; Hervieux, Paul-Antoine; Manfredi, Giovanni

    2018-01-01

    A semiclassical phase-space model is used to study the ultrafast charge and spin dynamics in thin ferromagnetic films. Both itinerant and localized magnetism are taken into account. It is shown that an oscillating spin current can be generated in the film via the application of a femtosecond laser pulse in the visible range.

  12. Laser beam diagnostics for metalworking applications

    International Nuclear Information System (INIS)

    Ramos, T.J.; Lingenfelter, A.C.

    1984-01-01

    The Materials Fabrication Division of Lawrence Livermore National Laboratory (LLNL) has three pulsed Nd-YAG lasers dedicated to metalworking. The units are used in a job shop primarily for welding. They also have a number of applications requiring cutting and drilling capability. Each of these metalworking operations requires somewhat different laser beam characteristics. As most investigators have found, the mode of the laser beam and the mode stability are the key variables which must be controlled if optimum results are to be achieved. The authors use several techniques to observe and measure these variables, i.e. Charge Couple Device (CCD) Camera, Thermal Image Plate and thermal-sensitive paper

  13. Current trends in the development of laser glasses

    Energy Technology Data Exchange (ETDEWEB)

    Lunter, S.G.; Mit' kin, V.M.; Tolstoi, M.N.; Fedorov, IU.K.

    1988-02-01

    The principal requirements for glasses suitable for use in solid state lasers are briefly discussed, and some current trends in the development of thermally stable laser-grade phosphate glasses based on I-III elements are reviewed. In particular, attention is given to the optimization of glass composition with respect to structural strength and low brittleness; development of new methods for machining and protecting the side surfaces of active elements; development of new glasses with low concentration quenching, such as a lithium-neodymium-lanthanum-phosphate glass; new neodymium glasses with high chemical stability and low crystallizability; and methods for the dehydration of erbium phosphate glasses. 24 references.

  14. Current developments with TRIUMF's titanium-sapphire laser based resonance ionization laser ion source. An overview

    Science.gov (United States)

    Lassen, J.; Li, R.; Raeder, S.; Zhao, X.; Dekker, T.; Heggen, H.; Kunz, P.; P. Levy, C. D.; Mostanmand, M.; Teigelhöfer, A.; Ames, F.

    2017-11-01

    Developments at TRIUMF's isotope separator and accelerator (ISAC) resonance ionization laser ion source (RILIS) in the past years have concentrated on increased reliability for on-line beam delivery of radioactive isotopes to experiments, as well as increasing the number of elements available through resonance ionization and searching for ionization schemes with improved efficiency. The current status of these developments is given with a list of two step laser ionization schemes implemented recently.

  15. Current developments with TRIUMF’s titanium-sapphire laser based resonance ionization laser ion source

    Energy Technology Data Exchange (ETDEWEB)

    Lassen, J., E-mail: LASSEN@triumf.ca; Li, R. [TRIUMF (Canada); Raeder, S. [GSI Helmholtzzentrum für Schwerionenforschung GmbH (Germany); Zhao, X.; Dekker, T. [TRIUMF (Canada); Heggen, H. [GSI Helmholtzzentrum für Schwerionenforschung GmbH (Germany); Kunz, P.; Levy, C. D. P.; Mostanmand, M.; Teigelhöfer, A.; Ames, F. [TRIUMF (Canada)

    2017-11-15

    Developments at TRIUMF’s isotope separator and accelerator (ISAC) resonance ionization laser ion source (RILIS) in the past years have concentrated on increased reliability for on-line beam delivery of radioactive isotopes to experiments, as well as increasing the number of elements available through resonance ionization and searching for ionization schemes with improved efficiency. The current status of these developments is given with a list of two step laser ionization schemes implemented recently.

  16. High energy laser demonstrators for defense applications

    Science.gov (United States)

    Jung, M.; Riesbeck, Th.; Schmitz, J.; Baumgärtel, Th.; Ludewigt, K.; Graf, A.

    2017-01-01

    Rheinmetall Waffe Munition has worked since 30 years in the area of High Energy Laser (HEL) for defence applications, starting from pulsed CO2 to pulsed glass rods lasers. In the last decade Rheinmetall Waffe Munition changed to diode pumped solid state laser (DPSSL) technology and has successfully developed, realised and tested a variety of versatile HEL weapon demonstrators for air- and ground defence scenarios like countering rocket, artillery, mortar, missile (RAMM), unmanned aerial systems (UAS) and unexploded ordnances clearing. By employing beam superimposing technology and a modular laser weapon concept, the total optical power has been successively increased. Stationary weapon platforms, military vehicles and naval platforms have been equipped with high energy laser effectors. The contribution gives a summary of the most recent development stages of Rheinmetalls HEL weapon program. In addition to the stationary 30 kW laser weapon demonstrator, we present vehicle based HEL demonstrators: the 5 kW class Mobile HEL Effector Track V, the 20 kW class Mobile HEL Effector Wheel XX and the 50 kW class Mobile HEL Effector Container L and the latest 10 kW HEL effector integrated in the naval weapon platform MLG 27. We describe the capabilities of these demonstrators against different potential targets. Furthermore, we will show the capability of the 30 kW stationary Laser Weapon Demonstrator integrated into an existing ground based air defence system to defeat saturated attacks of RAMM and UAS targets.

  17. CTE:YAG laser applications in dentistry

    Science.gov (United States)

    Shori, Ramesh K.; Fried, Daniel; Featherstone, John D. B.; Kokta, Milan R.; Duhn, Clifford W.

    1998-04-01

    The suitability of CTE:YAG laser radiation was investigated for caries preventive laser treatments and caries ablation. Although, CTE:YAG laser radiation at 2.69 micrometer is less highly absorbed by dental hard tissues than other erbium laser wavelengths, namely 2.79 and 2.94 micrometer, it can readily be transmitted through a conventional low hydroxyl fiber with minimal loss. These studies show that reasonable ablation rates and efficiencies are obtainable with both free running (200 microseconds) and Q-switched (100 ns) laser pulses on both dentin and enamel with the application of a relatively thick layer of water to the tissue surface. The water served to remove tissue char and debris from the ablation site leaving a clean crater. However, mechanical forces produced during the energetic ablative process resulted in peripheral mechanical damage to the tissue. Surface dissolution studies on enamel indicated that CTE:YAG radiation inhibited surface dissolution by organic acid by 60 - 70% compared to unirradiated controls, albeit, at fluences an order of magnitude higher than those required for CO2 laser radiation. This layer system may be suitable for dental hard tissue applications if mechanical damage can be mitigated. This work was supported by NIH/NIDR Grants R29DE12091 and R01DE09958.

  18. What makes for a successful laser application

    DEFF Research Database (Denmark)

    Olsen, Flemmming Ove

    1997-01-01

    suppliers do normally not pocess internal ressources for efficient application development, except for their key market segments.The industrial laser market is further characterized by the large divertisement in products: Is the optimum laser for a certain job a CO2- or a ND-YAG-laser? Ore perhaps a Copper...... the 10 new letters with requests from their sales offices around the world. The requests are sorted in three equal sized stacks: One for straight forwards jobs, one for possible jobs and one for impossible or very difficult jobs. What will they do? They will of course try to demonstrate the feasability...... of their lasers on the straight forward jobs. And if every things goes perfect, they might even manage to make a good test of one of the possible jobs. But, they have some jobs laying over from yesterday, and they miss some optical components to be able to demonstrate some af these jobs correctly, and tommorrow...

  19. Applications of laser ranging to ocean, ice, and land topography

    Science.gov (United States)

    Degnan, John J.

    1991-01-01

    The current status and some future applications of satellite laser ranging (SLR) are briefly reviewed. The demonstrated subcentimeter precision of ground-based SLR systems is attracting new users, particularly, in the area of high-resolution ocean, ice, and land topography. Future airborne or spaceborne SLR system will not only provide topographic data with a horizontal and vertical resolution never achieved previously, but, in addition, ground-based SLR systems, via precise tracking of spaceborne microwave and laser altimeters, will permit the expression of the topographic surface in a common geocentric reference frame.

  20. Laser applications in nuclear power plants

    Indian Academy of Sciences (India)

    2014-01-09

    Jan 9, 2014 ... This paper reports the state of the art of using a solid-state Nd:YAG laser for material processing applications such as cutting, welding and drilling of several components of operational nuclear reactors in radioactive environment. We have demonstrated several advantages of laserbased material processing ...

  1. Applications for Energy Recovering Free Electron Lasers

    Energy Technology Data Exchange (ETDEWEB)

    George Neil

    2007-08-01

    The availability of high-power, high-brilliance sources of tunable photons from energy-recovered Free Electron Lasers is opening up whole new fields of application of accelerators in industry. This talk will review some of the ideas that are already being put into production, and some of the newer ideas that are still under development.

  2. Laser weld jig. [Patent application

    Science.gov (United States)

    Van Blarigan, P.; Haupt, D.L.

    1980-12-05

    A system is provided for welding a workpiece along a predetermined weld line that may be of irregular shape, which includes the step of forming a lip on the workpiece to extend parallel to the weld line, and moving the workpiece by engaging the lip between a pair of rotatable members. Rotation of one of the members at a constant speed, causes the workpiece to move so that all points on the weld line sequentially pass a fixed point in space at a constant speed, so that a laser welding beam can be directed at that fixed point to form a weld along the weld line. The workpiece can include a reusable jig forming the lip, and with the jig constructed to detachably hold parts to be welded at a position wherein the weld line of the parts extends parallel to the lip on the jig.

  3. Laser applications in nanotechnology: nanofabrication using laser ablation and laser nanolithography

    International Nuclear Information System (INIS)

    Makarov, G N

    2013-01-01

    The fact that nanoparticles and nanomaterials have fundamental properties different both from their constituent atoms or molecules and from their bulk counterparts has stimulated great interest, both theoretical and practical, in nanoparticles and nanoparticle-based assemblies (functional materials), with the result that these structures have become the subject of explosive research over the last twenty years or so. A great deal of progress in this field has relied on the use of lasers. In this paper, the directions followed and results obtained in laser nanotechnology research are reviewed. The parameters, properties, and applications of nanoparticles are discussed, along with the physical and chemical methods for their fabrication and investigation. Nanofabrication applications of and fundamental physical principles behind laser ablation and laser nanolithography are discussed in detail. The applications of laser radiation are shown to range from fabricating, melting, and evaporating nanoparticles to changing their shape, structure, size, and size distribution, through studying their dynamics and forming them into periodic arrays and various structures and assemblies. The historical development of research on nanoparticles and nanomaterials and the application of laser nanotechnology in various fields are briefly reviewed. (reviews of topical problems)

  4. High-intensity laser application in Orthodontics

    Directory of Open Access Journals (Sweden)

    Eduardo Franzotti Sant’Anna

    Full Text Available ABSTRACT Introduction: In dental practice, low-level laser therapy (LLLT and high-intensity laser therapy (HILT are mainly used for dental surgery and biostimulation therapy. Within the Orthodontic specialty, while LLLT has been widely used to treat pain associated with orthodontic movement, accelerate bone regeneration after rapid maxillary expansion, and enhance orthodontic tooth movement, HILT, in turn, has been seen as an alternative for addressing soft tissue complications associated to orthodontic treatment. Objective: The aim of this study is to discuss HILT applications in orthodontic treatment. Methods: This study describes the use of HILT in surgical treatments such as gingivectomy, ulotomy, ulectomy, fiberotomy, labial and lingual frenectomies, as well as hard tissue and other dental restorative materials applications. Conclusion: Despite the many applications for lasers in Orthodontics, they are still underused by Brazilian practitioners. However, it is quite likely that this demand will increase over the next years - following the trend in the USA, where laser therapies are more widely used.

  5. Orthogonal polarization in lasers physical phenomena and engineering applications

    CERN Document Server

    Zhang, Shulian

    2013-01-01

    This practical book summarizes the latest research results of orthogonally polarized lasers, birefringence laser cavities, and their applications. Coverage ranges from basic principles and technologies to the characteristics of different cavities and lasers to various measurement techniques. A number of figures, experimental designs, and measurement curves are included, helping readers gain a thorough understanding of the many applications in modern engineering and start their own projects. Many types of relevant lasers (Helium/Neon lasers, Nd:YAG lasers, laser diodes, etc.) are also discussed

  6. Femtosecond laser's application in the corneal surgery

    Directory of Open Access Journals (Sweden)

    Shu-Liang Wang

    2015-10-01

    Full Text Available With the rapid development over the past two decades,femtosecond(10-15slasers(FShas become a new application in ophthalmic surgery. As laser power is defined as energy delivered per unit time, decreasing the pulse duration to femtosecond level(100fsnot only increases the power delivered but also decreases the fluence threshold for laser induced optical breakdown. In ablating tissue, FS has an edge over nanosecond lasers as there is minimal collateral damage from shock waves and heat conduction during surgical ablation. Thus, application of FS has been widely spread, from flap creation for laser-assisted in situ keratomileusis(LASIKsurgery, cutting of donor and recipient corneas in keratoplasty, creation of pockets for intracorneal ring implantation. FS applied in keratoplasty is mainly used in making graft and recipient bed, and can exactly cut different tissue of keratopathy. FS can also cut partial tissue of cornea, even if it is under the moderate corneal macula and corneal edema condition.

  7. Measurement of the target current by inductive probe during laser interaction on terawatt laser system PALS

    Czech Academy of Sciences Publication Activity Database

    Cikhardt, Jakub; Krása, Josef; De Marco, Massimo; Pfeifer, Miroslav; Velyhan, Andriy; Krouský, Eduard; Cikhardtová, B.; Klír, Daniel; Řezáč, Karel; Ullschmied, Jiří; Skála, Jiří; Kubeš, P.; Kravárik, J.

    2014-01-01

    Roč. 85, č. 10 (2014), s. 103507-103507 ISSN 0034-6748 R&D Projects: GA MŠk LM2010014; GA MŠk(CZ) LG13029; GA ČR GAP205/12/0454; GA MŠk EE2.3.20.0279 Grant - others:LaserZdroj (OP VK 3)(XE) CZ.1.07/2.3.00/20.0279 Institutional support: RVO:61389021 ; RVO:68378271 Keywords : laser PALS * laser-target interaction * target current * inductive probe Subject RIV: BL - Plasma and Gas Discharge Physics; BL - Plasma and Gas Discharge Physics (FZU-D) Impact factor: 1.614, year: 2014 http://dx.doi.org/10.1063/1.4898016

  8. Target current: a useful parameter for characterizing laser ablation

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; Giuffreda, E.; Delle Side, D.; Nassisi, V.; Klír, Daniel; Cikhardt, Jakub; Řezáč, Karel

    2017-01-01

    Roč. 35, č. 1 (2017), s. 170-176 ISSN 0263-0346 R&D Projects: GA ČR GA16-07036S; GA MŠk(CZ) LD14089; GA MŠk(CZ) LM2015083 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : impurities on target surface * positive and negative target polarization * space structure of ion front * target current in laser-produced plasmas Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 1.420, year: 2016

  9. Nanodiamonds of Laser Synthesis for Biomedical Applications.

    Science.gov (United States)

    Perevedentseva, E; Peer, D; Uvarov, V; Zousman, B; Levinson, O

    2015-02-01

    In recent decade detonation nanodiamonds (DND), discovered 50 years ago and used in diverse technological processes, have been actively applied in biomedical research as a drug and gene delivery carrier, a contrast agent for bio-imaging and diagnostics and an adsorbent for protein separation and purification. In this work we report about nanodiamonds of high purity produced by laser assisted technique, compare them with DND and consider the prospect and advantages of their use in the said applications.

  10. Intensity and frequency stabilization of a laser diode by simultaneously controlling its temperature and current

    Science.gov (United States)

    Mu, Weiwei; Hu, Zhaohui; Wang, Jing; Zhou, Binquan

    2017-10-01

    Nuclear magnetic resonance gyroscope (NMRG) detects the angular velocity of the vehicle utilizing the interaction between the laser beam and the alkali metal atoms along with the noble gas atoms in the alkali vapor cell. In order to reach high precision inertial measurement target, semiconductor laser in NMRG should have good intensity and frequency stability. Generally, laser intensity and frequency are stabilized separately. In this paper, a new method to stabilize laser intensity and frequency simultaneously with double-loop feedback control is presented. Laser intensity is stabilized to the setpoint value by feedback control of laser diode's temperature. Laser frequency is stabilized to the Doppler absorption peak by feedback control of laser diode's current. The feedback control of current is a quick loop, hence the laser frequency stabilize quickly. The feedback control of temperature is a slow loop, hence the laser intensity stabilize slowly. With the feedback control of current and temperature, the laser intensity and frequency are stabilized finally. Additionally, the dependence of laser intensity and frequency on laser diode's current and temperature are analyzed, which contributes to choose suitable operating range for the laser diode. The advantage of our method is that the alkali vapor cell used for stabilizing laser frequency is the same one as the cell used for NMRG to operate, which helps to miniaturize the size of NMRG prototype. In an 8-hour continuous measurement, the long-term stability of laser intensity and frequency increased by two orders of magnitude and one order of magnitude respectively.

  11. Medical laser application: translation into the clinics

    Science.gov (United States)

    Sroka, Ronald; Stepp, Herbert; Hennig, Georg; Brittenham, Gary M.; Rühm, Adrian; Lilge, Lothar

    2015-06-01

    Medical laser applications based on widespread research and development is a very dynamic and increasingly popular field from an ecological as well as an economic point of view. Conferences and personal communication are necessary to identify specific requests and potential unmet needs in this multi- and interdisciplinary discipline. Precise gathering of all information on innovative, new, or renewed techniques is necessary to design medical devices for introduction into clinical applications and finally to become established for routine treatment or diagnosis. Five examples of successfully addressed clinical requests are described to show the long-term endurance in developing light-based innovative clinical concepts and devices. Starting from laboratory medicine, a noninvasive approach to detect signals related to iron deficiency is shown. Based upon photosensitization, fluorescence-guided resection had been discovered, opening the door for photodynamic approaches for the treatment of brain cancer. Thermal laser application in the nasal cavity obtained clinical acceptance by the introduction of new laser wavelengths in clinical consciousness. Varicose veins can be treated by innovative endoluminal treatment methods, thus reducing side effects and saving time. Techniques and developments are presented with potential for diagnosis and treatment to improve the clinical situation for the benefit of the patient.

  12. Application of Low level Lasers in Dentistry (Endodontic).

    Science.gov (United States)

    Asnaashari, Mohammad; Safavi, Nassimeh

    2013-01-01

    Low level lasers, cold or soft lasers: These lasers do not produce thermal effects on tissues and induce photoreactions in cells through light stimulation which is called photobiostimulation. Power of these lasers is usually under 250mW. The main point differentiating low level lasers and high power ones is the activation of photochemical reactions without heat formation. The most important factor to achieve this light characteristic in lasers is not their power, but their power density for each surfa ceunit (i.e cm(2)). Density lower than 670mW/cm(2), can induce the stimulatory effects of low level lasers without thermal effects. Low level lasers (therapeutic) used today as treatment adjunctive devices in medicine and dentistry. Numerous studies have been performed on the applications of low level lasers in patient pain reduction. Mechanisms of pain reduction with therapeutic lasers and their application are expressed, and the studies realized in this field are presented.

  13. Application of Low level Lasers in Dentistry (Endodontic)

    Science.gov (United States)

    Asnaashari, Mohammad; Safavi, Nassimeh

    2013-01-01

    Low level lasers, cold or soft lasers: These lasers do not produce thermal effects on tissues and induce photoreactions in cells through light stimulation which is called photobiostimulation. Power of these lasers is usually under 250mW. The main point differentiating low level lasers and high power ones is the activation of photochemical reactions without heat formation. The most important factor to achieve this light characteristic in lasers is not their power, but their power density for each surfa ceunit (i.e cm2). Density lower than 670mW/cm2, can induce the stimulatory effects of low level lasers without thermal effects. Low level lasers (therapeutic) used today as treatment adjunctive devices in medicine and dentistry. Numerous studies have been performed on the applications of low level lasers in patient pain reduction. Mechanisms of pain reduction with therapeutic lasers and their application are expressed, and the studies realized in this field are presented. PMID:25606308

  14. High-power copper vapour lasers and applications

    Energy Technology Data Exchange (ETDEWEB)

    Chang, J.J.; Warner, B.E.; Boley, C.D.; Dragon, E.P.

    1995-08-01

    Expanded applications of copper vapor lasers has prompted increased demand for higher power and better beam quality. This paper reports recent progress in laser power scaling, MOPA operation, beam quality improvement, and applications in precision laser machining. Issues such as gas heating, radial delay, discharge instability, and window heating will also be discussed.

  15. Discrete mode lasers for communications applications

    Science.gov (United States)

    Barry, L. P.; Herbert, C.; Jones, D.; Kaszubowska-Anandarajah, A.; Kelly, B.; O'Carroll, J.; Phelan, R.; Anandarajah, P.; Shi, K.; O'Gorman, J.

    2009-02-01

    The wavelength spectra of ridge waveguide Fabry Perot lasers can be modified by perturbing the effective refractive index of the guided mode along very small sections of the laser cavity. One way of locally perturbing the effective index of the lasing mode is by etching features into the ridge waveguide such that each feature has a small overlap with the transverse field profile of the unperturbed mode, consequently most of the light in the laser cavity is unaffected by these perturbations. A proportion of the propagating light is however reflected at the boundaries between the perturbed and the unperturbed sections. Suitable positioning of these interfaces allows the mirror loss spectrum of a Fabry Perot laser to be manipulated. In order to achieve single longitudinal mode emission, the mirror loss of a specified mode must be reduced below that of the other cavity modes. Here we review the latest results obtained from devices containing such features. These results clearly demonstrate that these devices exceed the specifications required for a number of FTTH and Datacomms applications, such as GEPON, LX4 and CWDM. As well as this we will also present initial results on the linewidth of these devices.

  16. Ultrafast pulse lasers jump to macro applications

    Science.gov (United States)

    Griebel, Martin; Lutze, Walter; Scheller, Torsten

    2016-03-01

    Ultrafast Lasers have been proven for several micro applications, e.g. stent cutting, for many years. Within its development of applications Jenoptik has started to use ultrafast lasers in macro applications in the automotive industry. The JenLas D2.fs-lasers with power output control via AOM is an ideal tool for closed loop controlled material processing. Jenoptik enhanced his well established sensor controlled laser weakening process for airbag covers to a new level. The patented process enables new materials using this kind of technology. One of the most sensitive cover materials is genuine leather. As a natural product it is extremely inhomogeneous and sensitive for any type of thermal load. The combination of femtosecond pulse ablation and closed loop control by multiple sensor array opens the door to a new quality level of defined weakening. Due to the fact, that the beam is directed by scanning equipment the process can be split in multiple cycles additionally reducing the local energy input. The development used the 5W model as well as the latest 10W release of JenLas D2.fs and achieved amazing processing speeds which directly fulfilled the requirements of the automotive industry. Having in mind that the average cycle time of automotive processes is about 60s, trials had been done of processing weakening lines in genuine leather of 1.2mm thickness. Parameters had been about 15 cycles with 300mm/s respectively resulting in an average speed of 20mm/s and a cycle time even below 60s. First samples had already given into functional and aging tests and passed successfully.

  17. Optical Refrigeration Science and Applications of Laser Cooling of Solids

    CERN Document Server

    Epstein, Richard

    2009-01-01

    Edited by the two top experts in the field with a panel of International contributors, this is a comprehensive up-to-date review of research and applications. Starting with the basic physical principles of laser cooling of solids, the monograph goes on to discuss the current theoretical issues being resolved and the increasing demands of growth and evaluation of high purity materials suitable for optical refrigeration, while also examining the design and applications of practical cryocoolers. An advanced text for scientists, researchers, engineers, and students (masters, PHDs and Postdoc) in l

  18. Applications of Free Electron Lasers in Biology and Medicine

    International Nuclear Information System (INIS)

    Pelka, J.B.; Tybor, K.R.; Nietubyc, R.; Wrochna, G.

    2010-01-01

    The advent of free electron lasers opens up new opportunities to probe the dynamics of ultrafast processes and the structure of matter with unprecedented spatial and temporal resolution. New methods inaccessible with other known types of radiation sources can be developed, resulting in a breakthrough in deep understanding the fundamentals of life as well as in numerous medical and biological applications. In the present work the properties of free electron laser radiation that make the sources excellent for probing biological matter at an arbitrary wavelength, in a wide range of intensities and pulse durations are briefly discussed. A number of biophysical and biomedical applications of the new sources, currently considered among the most promising in the field, are presented. (author)

  19. On a laser beam fiducial line application for metrological purposes

    International Nuclear Information System (INIS)

    Batusov, V.; Budagov, J.; Lyablin, M.; Rusakovich, N.; Sisakyan, A.; Topilin, N.; Khubua, J.; Lasseur, C.

    2008-01-01

    The possibility of a collimated one-mode laser beam used as a fiducial line is considered. The technology of an 'extended' laser beam formation and application for a much extended fiducial line is proposed

  20. Industrial Applications Of Low-Power CO2 Lasers

    Science.gov (United States)

    Wheeler, John P.

    1986-11-01

    Until recently, applications of carbon dioxide (CO2) lasers in industry have primarily used high-power laser systems for cutting and welding. Today, the most rapid growth rate is occuring in applications of small, sealed laser systems to soldering, wirestripping, marking, sealing, degating and slitting of a wide variety of materials. In the future, small CO2 laser based systems will be in use in shopping centers and department stores, and unit sales will be in the multiple thousands per year.

  1. Laser velocimeter application to oscillatory liquid flows

    Science.gov (United States)

    Gartrell, L. R.

    1978-01-01

    A laser velocimeter technique was used to measure the mean velocity and the frequency characteristics of an oscillatory flow component generated with a rotating flapper in liquid flow system at Reynolds numbers approximating 93,000. The velocity information was processed in the frequency domain using a tracker whose output was used to determine the flow spectrum. This was accomplished with the use of an autocorrelator/Fourier transform analyzer and a spectrum averaging analyzer where induced flow oscillations up to 40 Hz were detected. Tests were conducted at a mean flow velocity of approximately 2 m/s. The experimental results show that the laser velocimeter can provide quantitative information such as liquid flow velocity and frequency spectrum with a possible application to cryogenic fluid flows.

  2. Development of Advanced Seed Laser Modules for Lidar and Spectroscopy Applications

    Science.gov (United States)

    Prasad, Narasimha S.; Rosiewicz, Alex; Coleman, Steven M.

    2013-01-01

    We report on recent progress made in the development of highly compact, single mode, distributed feedback laser (DFB) seed laser modules for lidar and spectroscopy applications from space based platforms. One of the intended application of this technology is in the NASA's Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The DFB laser modules operating at 1571 nm and 1262 nm have advanced current and temperature drivers built into them. A combination of temperature and current tuning allows coarse and fine adjustment of the diode wavelengths.

  3. 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.

  4. High resolution laser beam induced current images under trichromatic laser radiation: approximation to the solar irradiation.

    Science.gov (United States)

    Navas, F J; Alcántara, R; Fernández-Lorenzo, C; Martín-Calleja, J

    2010-03-01

    A laser beam induced current (LBIC) map of a photoactive surface is a very useful tool when it is necessary to study the spatial variability of properties such as photoconverter efficiency or factors connected with the recombination of carriers. Obtaining high spatial resolution LBIC maps involves irradiating the photoactive surface with a photonic beam with Gaussian power distribution and with a low dispersion coefficient. Laser emission fulfils these characteristics, but against it is the fact that it is highly monochromatic and therefore has a spectral distribution different to solar emissions. This work presents an instrumental system and procedure to obtain high spatial resolution LBIC maps in conditions approximating solar irradiation. The methodology developed consists of a trichromatic irradiation system based on three sources of laser excitation with emission in the red, green, and blue zones of the electromagnetic spectrum. The relative irradiation powers are determined by either solar spectrum distribution or Planck's emission formula which provides information approximate to the behavior of the system if it were under solar irradiation. In turn, an algorithm and a procedure have been developed to be able to form images based on the scans performed by the three lasers, providing information about the photoconverter efficiency of photovoltaic devices under the irradiation conditions used. This system has been checked with three photosensitive devices based on three different technologies: a commercial silicon photodiode, a commercial photoresistor, and a dye-sensitized solar cell. These devices make it possible to check how the superficial quantum efficiency has areas dependent upon the excitation wavelength while it has been possible to measure global incident photon-to-current efficiency values approximating those that would be obtained under irradiation conditions with sunlight.

  5. 3D laser microfabrication principles and applications

    CERN Document Server

    Misawa, Hiroaki

    2006-01-01

    A thorough introduction to 3D laser microfabrication technology, leading readers from the fundamentals and theory to its various potent applications, such as the generation of tiny objects or three-dimensional structures within the bulk of transparent materials. The book also presents new theoretical material on dielectric breakdown, allowing a better understanding of the differences between optical damage on surfaces and inside the bulk, as well as a look into the future.Chemists, physicists, materials scientists and engineers will find this a valuable source of interdisciplinary know

  6. Laser surface treatment of grey cast iron for automotive applications

    NARCIS (Netherlands)

    Ocelik, V.; Tang, P.N.; de Boer, M.C.; de Oliveira, U.; de Hosson, J.T.M.; DeHosson, JTM; Brebbia, CA; Nishida, SI

    2005-01-01

    The surface of pearlitic grey cast iron was treated using a 2 kW Nd:YAG laser beam with the final aim to improve its surface properties, mainly for automotive applications. Two kinds of laser surface treatments were experimentally applied. In the laser surface hardening approach the surface of cast

  7. Future scientific applications for high-energy lasers

    Energy Technology Data Exchange (ETDEWEB)

    Lee, R.W. [comp.

    1994-08-01

    This report discusses future applications for high-energy lasers in the areas of astrophysics and space physics; hydrodynamics; material properties; plasma physics; radiation sources; and radiative properties.

  8. Paediatric laser dentistry. Part 2: Hard tissue laser applications.

    Science.gov (United States)

    Olivi, G; Caprioglio, C; Olivi, M; Genovese, M D

    2017-06-01

    Erbium lasers can provide effective and minimally invasive caries removal in children. The bonding phase remains a critic step as well as the choice of material. Glass ionomers exhibits lower bonding properties in laser irradiated teeth compared to the conventional method or to composite and resin modified glass ionomer. Laser can also provide effective decontamination and coagulation effects in vital and non vital pulp therapy of primary teeth, improving and simplifying the cleaning and disinfecting steps.

  9. Intense ion beams from laser plasma : production and application

    International Nuclear Information System (INIS)

    Bykovsky, Yu.A.; Kozlovsky, K.I.; Shikanov, A.E.

    1994-01-01

    The production of intense ion beams from plasma injectors using laser-induced plasma bundles are considered. Laser plasma bundles with quantity of ions about 10 sup 1 sup 5 - 10 sup 1 sup 6 imp sup -1 are created by interaction of laser irradiation ( q = 10 sup 9 - 10 sup 1 sup 3 W / cm sup 2, less than 'thermonuclear' intensities, lambda - 0.53 - 10.6 micro, E 0.1 - 10 J/ imp )with various solid targets in vacuum. By changing laser parameters and focusing conditions it is able to produce ions from very wide spectrum of chemical elements and of different charge. High density moving plasma gives the possibility to extract and to form in time up to 1 - 3 microsecond ion current equal 10-10 sup 3 A. Some types of such injector for radiation physics arrangements were elaborated. The main goals of the application of these equipment are the following : - acceleration of multiply charged ions in big accelerators; - ion implantation and material modification; - generation of intense pulse neutron fluxes; - vaporization of material and special layers creation. 4 refs., (author)

  10. Pulsed eddy currents: principle and applications

    International Nuclear Information System (INIS)

    Bernard, A.; Coutanceau, N.

    1993-04-01

    Eddy currents are widely used as a non destructive testing technique specially for heat exchanger testing. The specificities of pulsed eddy current testing are analyzed in terms of probe design and signal processing. The specific applications are detailed. They are divided in two parts. First part, deals with the two main applications of the high peak energy supplied to the probe. One concerns the design of focused probes used for the detection of small defects in irradiated fuel rods. The other concerns the saturation of ferromagnetic materials in order to test the full thickness of the exchanger tubes. Second part, deals with applications of the wide and low frequency spectrum generated by the pulse source. It enables the testing of thick materials, and the detection of sub-surface defects. It has been tested on austenitic steel (nuclear pressure vessel nozzle), multilayered structures of aluminium alloys (aeronautics) and sleeved structures (nuclear pressure vessel head penetrations through thermal sleeves)

  11. Femtosecond laser-matter interaction theory, experiments and applications

    CERN Document Server

    Gamaly, Eugene G

    2011-01-01

    Basics of Ultra-Short Laser-Solid InteractionsSubtle Atomic Motion Preceding a Phase Transition: Birth, Life and Death of PhononsUltra-Fast Disordering by fs-Lasers: Superheating Prior to Entropy CatastropheAblation of SolidsUltra-Short Laser-Matter Interaction Confined Inside a Bulk of Transparent SolidApplications of Ultra-Short Laser-Matter InteractionsConclusion Remarks.

  12. Development of State of the Art Solid State Lasers for Altimetry and other LIDAR Applications

    Science.gov (United States)

    Kay, Richard B.

    1997-01-01

    This report describes work performed and research accomplished through the end of 1997. During this time period, we have designed and fabricated two lasers for flight LIDAR applications to medium altitudes (Laser Vegetation Imaging System designs LVIS 1 and LVIS 2), designed one earth orbiting LIDAR transmitter (VCL-Alt), and continued work on a high rep-rate LIDAR laser (Raster Scanned Altimeter, RASCAL). Additionally, a 'White Paper' was prepared which evaluates the current state of the art of Nd:YAG lasers and projects efficiencies to the year 2004. This report is attached as Appendix 1 of this report.

  13. Nonablative lasers and nonlaser systems in dermatology: Current status

    OpenAIRE

    Mukta Sachdev; Sunaina Hameed; Venkataram Mysore

    2011-01-01

    Nonablative lasers and nonlaser systems are newer systems used for skin rejuvenation, tightening, body sculpting, and scar remodeling. Devices: Different technologies such as lasers, Intense Pulsed Light (IPL), and radiofrequency have been introduced. Most nonablative laser systems emit light within the infrared portion of the electromagnetic spectrum (1000-1500nm). At these wavelengths, absorption by superficial water containing tissue is relatively weak, thereby effecting deeper tissue pene...

  14. Current trends in context-aware applications

    Directory of Open Access Journals (Sweden)

    Andrea Loayza

    2013-12-01

    Full Text Available (Received: 2013/10/07 - Accepted: 2013/12/10Context-aware applications adapt their behavior and settings according to the environment conditions and to the user preferences. This state-of-the-art survey identifies the current trends related to the technics and tools for the development of this kind of software, as well as the areas of interest of the scientific community on the subject. It stands out the research on multimodal interfaces, localization, activity detection, interruptions control, predictive and wellbeing applications.

  15. Laser wakefield accelerator based light sources: potential applications and requirements

    Energy Technology Data Exchange (ETDEWEB)

    Albert, F. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). NIF and Photon Sciences; Thomas, A. G. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Nuclear Engineering and Radiological Sciences; Mangles, S. P.D. [Imperial College, London (United Kingdom). Blackett Lab.; Banerjee, S. [Univ. of Nebraska, Lincoln, NE (United States); Corde, S. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Flacco, A. [ENSTA, CNRS, Ecole Polytechnique, Palaiseau (France); Litos, M. [SLAC National Accelerator Lab., Menlo Park, CA (United States); Neely, D. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Viera, J. [Univ. of Lisbon (Portugal). GoLP-Inst. de Plasmas e Fusao Nuclear-Lab. Associado; Najmudin, Z. [Imperial College, London (United Kingdom). Blackett Lab.; Bingham, R. [Science and Technology Facilities Council (STFC), Oxford (United Kingdom). Rutherford Appleton Lab. (RAL). Central Laser Facility; Joshi, C. [Univ. of California, Los Angeles, CA (United States). Dept. of Electrical Engineering; Katsouleas, T. [Duke Univ., Durham, NC (United States). Platt School of Engineering

    2015-01-15

    In this article we review the prospects of laser wakefield accelerators as next generation light sources for applications. This work arose as a result of discussions held at the 2013 Laser Plasma Accelerators Workshop. X-ray phase contrast imaging, X-ray absorption spectroscopy, and nuclear resonance fluorescence are highlighted as potential applications for laser-plasma based light sources. We discuss ongoing and future efforts to improve the properties of radiation from plasma betatron emission and Compton scattering using laser wakefield accelerators for these specific applications.

  16. El láser y la fotónica en la Cirugía Plástica española e iberoamericana: Antecedentes históricos, aplicaciones actuales y proyectos de desarrollo inmediato Laser and photonics in Plastic Surgery in Spain and Latinamerica: Historical background, current applications and proyects of inmediate development

    Directory of Open Access Journals (Sweden)

    P.A. Martínez-Carpio

    2010-03-01

    Full Text Available La sociedad moderna valora y demanda los tratamientos láser por encima de otras posibilidades. En Cirugía Plástica los tratamientos fototerápicos y el láser se utilizan rutinariamente para combatir la diversa amalgama de signos senescentes de la piel. También, como herramienta ocasionalmente ventajosa en cirugía incisional, estética, óculo-plástica y reconstructiva. En esta revisión se plantea un panorama ecléctico sobre las posibilidades actuales del láser en el dominio del cirujano plástico, diferenciando un modelo reduccionista y un modelo integrador en el abordaje especializado de la Fotónica Médica y la Cirugía Láser. Se destaca la labor de la Sociedad Española de Láser Médico-Quirúrgico como nexo de unión entre Europa e Iberoamérica en la investigación, docencia y asistencia en esta materia.Modern society values and demands laser treatment above other therapeutical options. In Plastic Surgery, phototherapy treatments and lasers are used on a day to day basis against the broad amalgam of signs of aging skin. Sometimes they are also used as an advantageous instrument in incisional, aesthetic, oculoplastic and reconstructive surgery. In this review, we offer an eclectic overview of the current possibilities for laser applications in Plastic Surgery, defining a model in which the surgeon can integrate all of the available offer in Medical Photonics and Laser Surgery not merely based on the use of laser. We highlight the role of the Spanish Society of Medical Surgical Laser as a link between Europe and Latinamerica in research, teaching and assistance in this field.

  17. Current trends in Bayesian methodology with applications

    CERN Document Server

    Upadhyay, Satyanshu K; Dey, Dipak K; Loganathan, Appaia

    2015-01-01

    Collecting Bayesian material scattered throughout the literature, Current Trends in Bayesian Methodology with Applications examines the latest methodological and applied aspects of Bayesian statistics. The book covers biostatistics, econometrics, reliability and risk analysis, spatial statistics, image analysis, shape analysis, Bayesian computation, clustering, uncertainty assessment, high-energy astrophysics, neural networking, fuzzy information, objective Bayesian methodologies, empirical Bayes methods, small area estimation, and many more topics.Each chapter is self-contained and focuses on

  18. Tunable lasers and their application in analytical chemistry

    Science.gov (United States)

    Steinfeld, J. I.

    1975-01-01

    The impact that laser techniques might have in chemical analysis is examined. Absorption, scattering, and heterodyne detection is considered. Particular emphasis is placed on the advantages of using frequency-tunable sources, and dye solution lasers are regarded as the outstanding example of this type of laser. Types of spectroscopy that can be carried out with lasers are discussed along with the ultimate sensitivity or minimum detectable concentration of molecules that can be achieved with each method. Analytical applications include laser microprobe analysis, remote sensing and instrumental methods such as laser-Raman spectroscopy, atomic absorption/fluorescence spectrometry, fluorescence assay techniques, optoacoustic spectroscopy, and polarization measurements. The application of lasers to spectroscopic methods of analysis would seem to be a rewarding field both for research in analytical chemistry and for investments in instrument manufacturing.

  19. CERN's web application updates for electron and laser beam technologies

    CERN Document Server

    Sigas, Christos

    2017-01-01

    This report describes the modifications at CERN's web application for electron and laser beam technologies. There are updates at both the front and the back end of the application. New electron and laser machines were added and also old machines were updated. There is also a new feature for printing needed information.

  20. Laser applications in oral surgery and implant dentistry.

    Science.gov (United States)

    Deppe, Herbert; Horch, Hans-Henning

    2007-11-01

    Lasers have been used for many years in oral surgery and implant dentistry. In some indications, laser treatment has become state of the art as compared to conventional techniques. This article is a comprehensive review of new laser applications in oral surgery and implant dentistry. One of the most interesting developments over the last years was the introduction of the 9.6-microm CO(2) laser. It has been shown in the recent literature that the use of this new device can preserve tissue with almost no adverse effects at the light microscopic level. In contrast, modifications of approved CO(2) laser therapies of premalignant lesions resulted in higher recurrence rates than the conventional defocused laser technique. However, several studies indicate that other wavelengths such as Nd-YAG (lambda = 1,064 nm) or diode lasers (lambda = 810 nm) may be also of value in this field. In many other indications, the use of lasers is still experimental. Intraoperatively used photodynamic therapy or peri-implant care of ailing implants with the CO(2) laser seems to be more of value than conventional methods. However, further studies are required to assess standard protocols. Over the past years, research identified some new indications for laser treatment in oral surgery and implant dentistry. Moreover, well-known laser applications were defined as state of the art. Nevertheless, further studies are required for laser treatment in oral surgery and implant dentistry.

  1. Laser ignition application in a space experiment

    Science.gov (United States)

    Liou, Larry C.; Culley, Dennis E.

    1993-01-01

    A laser ignition system is proposed for the Combustion Experiment Module on an orbiting spacecraft. The results of a design study are given using the scheduled 'Flame Ball Experiment' as the design guidelines. Three laser ignition mechanisms and wavelengths are evaluated. A prototype laser is chosen and its specifications are given, followed by consideration of the beam optical arrangement, the ignition power requirement, the laser ignition system weight, size, reliability, and laser cooling and power consumption. Electromagnetic interference to the onboard electronics caused by the laser ignition process is discussed. Finally, ground tests are suggested.

  2. Comparison of low level laser therapy and interferential current on post stroke shoulder pain.

    Science.gov (United States)

    Jan, Fahmida; Naeem, Aamir; Malik, Arshad Nawaz; Amjad, Imran; Malik, Tariq

    2017-05-01

    The objective of the study was to compare the effects of LASER therapy and Interferential current on post stroke shoulder pain. Diagnosed patients (n=38) of post stroke shoulder pain were randomly divided into two groups i.e., LASER group (LG =20 patients) and Interferential current group (IFCG=18 patients). The variables under study were pain, satisfaction, disability, and function level before and after treatment. Improvement in pain and satisfaction level after LASER therapy was significant (p 0.05). The study findings revealed that LASER therapy is more effective than Interferential current in decreasing pain and increasing satisfaction level of stroke patients having shoulder pain.

  3. Medical Applications of Laser Induced Breakdown Spectroscopy

    Science.gov (United States)

    Pathak, A. K.; Rai, N. K.; Singh, Ankita; Rai, A. K.; Rai, Pradeep K.; Rai, Pramod K.

    2014-11-01

    Sedentary lifestyle of human beings has resulted in various diseases and in turn we require a potential tool that can be used to address various issues related to human health. Laser Induced Breakdown Spectroscopy (LIBS) is one such potential optical analytical tool that has become quite popular because of its distinctive features that include applicability to any type/phase of samples with almost no sample preparation. Several reports are available that discusses the capabilities of LIBS, suitable for various applications in different branches of science which cannot be addressed by traditional analytical methods but only few reports are available for the medical applications of LIBS. In the present work, LIBS has been implemented to understand the role of various elements in the formation of gallstones (formed under the empyema and mucocele state of gallbladder) samples along with patient history that were collected from Purvancal region of Uttar Pradesh, India. The occurrence statistics of gallstones under the present study reveal higher occurrence of gallstones in female patients. The gallstone occurrence was found more prevalent for those male patients who were having the habit of either tobacco chewing, smoking or drinking alcohols. This work further reports in-situ LIBS study of deciduous tooth and in-vivo LIBS study of human nail.

  4. Medical Applications of Laser Induced Breakdown Spectroscopy

    International Nuclear Information System (INIS)

    Pathak, A K; Rai, N K; Singh, Ankita; Rai, A K; Rai, Pradeep K; Rai, Pramod K

    2014-01-01

    Sedentary lifestyle of human beings has resulted in various diseases and in turn we require a potential tool that can be used to address various issues related to human health. Laser Induced Breakdown Spectroscopy (LIBS) is one such potential optical analytical tool that has become quite popular because of its distinctive features that include applicability to any type/phase of samples with almost no sample preparation. Several reports are available that discusses the capabilities of LIBS, suitable for various applications in different branches of science which cannot be addressed by traditional analytical methods but only few reports are available for the medical applications of LIBS. In the present work, LIBS has been implemented to understand the role of various elements in the formation of gallstones (formed under the empyema and mucocele state of gallbladder) samples along with patient history that were collected from Purvancal region of Uttar Pradesh, India. The occurrence statistics of gallstones under the present study reveal higher occurrence of gallstones in female patients. The gallstone occurrence was found more prevalent for those male patients who were having the habit of either tobacco chewing, smoking or drinking alcohols. This work further reports in-situ LIBS study of deciduous tooth and in-vivo LIBS study of human nail

  5. Spectroscopic and Dynamic Applications of Laser - Interactions.

    Science.gov (United States)

    Quesada, Mark Alejandro

    1987-05-01

    Five different studies of laser-molecule interactions are conducted in this thesis. In part one, the first observation of Autler-Townes splitting of molecules is discussed and used to measure vibronic transition moments between excited electronic states. The effect was observed in the two-color, four -photon ionization of hydrogen via the resonant levels E,F(v = 6, J = 1) and D(v = 2, J = 2). Calculations gave good fits to the observed spectra yielding a vibronic transition moment of 2.0 +/- 0.5 a.u. between the above excited states. In part two, a method for extracting the alignment parameters of a molecular angular momentum distribution using laser-induced fluorescence is presented. The treatment is applicable to the common case of cylindrically symmetric orientation distributions in the high J-limit. Four different combinations of rotational branches in the LIF absorption emission process are examined. Computer algebra programs are used to generate simple analytical expressions which account for the influence of saturation on determining alignment parameters. In part three, the application of MPI-optogalvanic spectroscopy to the molecule 1,4-diazabicyclo (2.2.2) octane (DABCO) at various levels in a methane/air flame environment is described. The method employs a burner design that permits access to preheated and primary reaction zones of the flame for laser probing. Hot bands arising from two-photon resonant (X_1 ' to A_1') transitions are measured and the intramolecular vibrational potentials for the ground and first excited state are determined. In part four, DABCO's nu_ {13} torsional mode relaxation in a helium -DABCO and argon-DABCO supersonic jet, under low expansion conditions, is discussed. Modeling of the relaxation using the linear Landau-Teller relaxation equation is undertaken with various attempts to incorporate the effects of velocity slip. The relaxation rate is found to be independent of slip and the cross section dependent on the inverse of

  6. Compact variable rate laser for space application

    Data.gov (United States)

    National Aeronautics and Space Administration — We will focus on the development and test of high reliable, radiation tolerant, compact laser for planetary mission.  The laser will be able to operate at variable...

  7. Laser application in otology for hearing restoration

    Science.gov (United States)

    Lombardo, Igino

    1994-09-01

    Prior to the development of the stapes replacement prosthesis in the early 1950s, loss of hearing due to otosclerosis remained an untreatable disease. Today, loss of hearing due to otosclerosis can be restored in the majority of cases to near normal levels. Since 1980 the laser has played a major and important role in otosclerosis surgery. This paper explores the use of lasers for hearing restoration and compares the results of laser surgery to non-laser surgery.

  8. High-power lasers for directed-energy applications.

    Science.gov (United States)

    Sprangle, Phillip; Hafizi, Bahman; Ting, Antonio; Fischer, Richard

    2015-11-01

    In this article, we review and discuss the research programs at the Naval Research Laboratory (NRL) on high-power lasers for directed-energy (DE) applications in the atmosphere. Physical processes affecting propagation include absorption/scattering, turbulence, and thermal blooming. The power levels needed for DE applications require combining a number of lasers. In atmospheric turbulence, there is a maximum intensity that can be placed on a target that is independent of the initial beam spot size and laser beam quality. By combining a number of kW-class fiber lasers, scientists at the NRL have successfully demonstrated high-power laser propagation in a turbulent atmosphere and wireless recharging. In the NRL experiments, four incoherently combined fiber lasers having a total power of 5 kW were propagated to a target 3.2 km away. These successful high-power experiments in a realistic atmosphere formed the basis of the Navy's Laser Weapon System. We compare the propagation characteristics of coherently and incoherently combined beams without adaptive optics. There is little difference in the energy on target between coherently and incoherently combined laser beams for multi-km propagation ranges and moderate to high levels of turbulence. Unlike incoherent combining, coherent combining places severe constraints on the individual lasers. These include the requirement of narrow power spectral linewidths in order to have long coherence times as well as polarization alignment of all the lasers. These requirements are extremely difficult for high-power lasers.

  9. Solar pumped laser and its application to hydrogen production

    International Nuclear Information System (INIS)

    Imasaki, K.; Saiki, T.; Li, D.; Motokosi, S.; Nakatsuka, M.

    2007-01-01

    Solar pumped laser has been studied. Recently, a small ceramic laser pumped by pseudo solar light shows high efficiency of more than 40% which exceeds a solar cell. Such solar pumped laser can concentrate the large area of solar energy in a focused spot of small area. This fact implies the application of such laser for clean and future renewable energy source as hydrogen. For this purpose, 100 W level laboratory solar laser HELIOS is completed using disk ceramic active mirror laser to achieve high temperature. This laser is a kind of MOPA system. Oscillator of additional small laser is used. Laser light is generated in oscillator and is amplified in ceramic disks of solar pumped. The temperature from this system is to be more than 1500 K. We will use a simple graphite cavity for laser power absorption and to get a high temperature. We are also designing a 10 MW CW laser based on this technology. This may be expected an application of solar energy for hydrogen production with total efficiency of 30%

  10. Current status of the laser diode array projector technology

    Science.gov (United States)

    Beasley, D. Brett; Saylor, Daniel A.

    1998-07-01

    This paper describes recent developments and the current status of the Laser Diode Array Projector (LDAP) Technology. The LDAP is a state-of-the-art dynamic infrared scene projector system capable of generating high resolution in-band infrared imagery at high frame rates. Three LDAPs are now operational at the U.S. Army Aviation and Missile Command's (AMCOM) Missile Research, Development, and Engineering Center (MRDEC). These projectors have been used to support multiple Hardware-in-the-Loop test entries of various seeker configurations. Seeker configurations tested include an InSb 256 X $256 focal-plane array (FPA), an InSb 512 X 512 FPA, a PtSi 640 X 480 FPA, a PtSi 256 X 256 FPA, an uncooled 320 X 240 microbolometer FPA, and two dual field- of-view (FOV) seekers. Several improvements in the projector technology have been made since we last reported in 1997. The format size has been increased to 544 X 544, and 672 X 512, and it has been proven that the LDAP can be synchronized without a signal from the unit-under test (UUT). The control software has been enhanced to provide 'point and click' control for setup, calibration, image display, image capture, and data analysis. In addition, the first long-wave infrared (LWIR) LDAP is now operational, as well as a dual field of view LDAP which can change its FOV within 0.25 seconds. The projector is interfaced to a Silicon Graphics scene generation computer which is capable of real-time 3-D scene generation. Sample images generated with the projector and captured by an InSb FPA sensor are included in the text.

  11. Current concepts in the use of lasers in periodontal and implant dentistry.

    Science.gov (United States)

    Romanos, Georgios

    2015-01-01

    Lasers have various periodontal applications including calculus removal (Er: YAG, Er, Cr: YSGG lasers); soft tissue excision, incision and ablation; decontamination of root and implant surfaces; biostimulation; bacteria reduction; and osseous surgery. This paper reviews some of the major opportunities for using lasers in periodontal and implant specialty practices. The literature relating to the use of lasers for removal of the pocket epithelium, root conditioning, bacterial reduction and decontamination of infected implant surfaces is discussed, and a summary of the advantages and disadvantages of using lasers for periodontal treatment is provided.

  12. Genome Writing: Current Progress and Related Applications

    Directory of Open Access Journals (Sweden)

    Yueqiang Wang

    2018-02-01

    Full Text Available The ultimate goal of synthetic biology is to build customized cells or organisms to meet specific industrial or medical needs. The most important part of the customized cell is a synthetic genome. Advanced genomic writing technologies are required to build such an artificial genome. Recently, the partially-completed synthetic yeast genome project represents a milestone in this field. In this mini review, we briefly introduce the techniques for de novo genome synthesis and genome editing. Furthermore, we summarize recent research progresses and highlight several applications in the synthetic genome field. Finally, we discuss current challenges and future prospects. Keywords: Synthetic biology, Genome writing, Genome editing, Bioethics, Biosafety

  13. Quantum Cascade Lasers Modulation and Applications

    Science.gov (United States)

    Luzhansky, Edward

    The mid-wave IR (MWIR) spectral band, extending from 3 to 5 microns, is considered to be a low loss atmospheric window. There are several spectral sub-bands with relatively low atmospheric attenuation in this region making it popular for various commercial and military applications. Relatively low thermal and solar background emissions, effective penetration through the natural and anthropogenic obscurants and eye safety add to the long list of advantages of MWIR wavelengths. Quantum Cascade Lasers are compact semiconductor devices capable of operating in MWIR spectrum. They are based on inter-subband transitions in a multiple-quantum-well (QW) hetero-structure, designed by means of band-structure engineering. The inter-subband nature of the optical transition has several key advantages. First, the emission wavelength is primarily a function of the QW thickness. This characteristic allows choosing well-understood and reliable semiconductors for the generation of light in a wavelength range of interest. Second, a cascade process in which tens of photons are generated per injected electron. This cascading process is behind the intrinsic high-power capabilities of QCLs. This dissertation is focused on modulation properties of Quantum Cascade Lasers. Both amplitude and phase/frequency modulations were studied including modulation bandwidth, modulation efficiency and chirp linearity. Research was consisted of the two major parts. In the first part we describe the theory of frequency modulation (FM) response of Distributed Feedback Quantum Cascade Lasers (DFB QCL). It includes cascading effect on the QCL's maximum modulation frequency. The "gain levering" effect for the maximum FM response of the two section QCLs was studied as well. In the second part of research we concentrated on the Pulse Position Amplitude Modulation of a single section QCL. The low complexity, low size, weight and power Mid-Wavelength Infra-Red optical communications transceiver concept is

  14. Medical application of laser hair removal

    International Nuclear Information System (INIS)

    Fadlalla, Alwalled Hussein Ataalmannan

    2015-12-01

    The use of laser in medical treatment has become of paramount importance proportional to what has high therapeutic privileges such as speed and accuracy in penetrating tissues and high quality especially when used in hair removal which is the subject of our study, this laser operates cards may cause some change in the color of the skin when used in a manner that is correct ratio of the thermal impact force in the laser hair removal process, or if it is exposed directly to his eye. This study is a comparison between the physical properties of laser of lasers used in hair removal, according to previous studies to be the basis for the benefit of doctors who use lasers for hair removal. The aim of this study was to study the effect of laser hair removal using the Nd: YAG laser with a wavelength 1064 nm as well as the risks airing from the assessment. The aim of this study was to identify the appropriate laser energy that absorbed in the hair follicle with a dark color and the appropriate thermal effect occurs to vaporize the follicle cell, a 40 J/cm 2 is to be significant without side effects for healthy tissue. In this study doses for a few laser beam is considered when compared to previous studies. Laser danger to the patient during the operation increases with increasing laser energy emitted during treatment. Laser hair removal by the user and energy emitted by wavelength of the laser device also depends on the hair color and roughness as well as skin color. (Author)

  15. New quantum cascade laser sources for sensing applications (Conference Presentation)

    Science.gov (United States)

    Troccoli, Mariano

    2017-05-01

    In this presentation we will review our most recent results on development of Quantum Cascade Lasers (QCLs) for analytical and industrial applications. QCLs have demonstrated the capability to cover the entire range of Mid-IR, Far-IR, and THz wavelengths by skillful tuning of the material design and composition and by use of intrinsic material properties via a set of techniques collectively called "bandgap engineering". The use of MOCVD, pioneered on industrial scale by AdTech Optics, has enabled the deployment of QCL devices into a diverse range of environments and applications. QCLs can be tailored to the specific application requirements due to their unprecedented flexibility in design and thanks to the leveraging of well-known III-V fabrication technologies inherited from the NIR domain. Nevertheless, several applications and new frontiers in R and D need the constant support of new developments in device features, capabilities, and performances. We have developed a wide range of devices, from high power, high efficiency multi-mode sources, to narrow-band, single mode devices with low-power consumption, and from non-linear, multi-wavelength generating devices to broadband sources and multi-emitter arrays. All our devices are grown and processed using MOCVD technology and allow us to attain competitive performances across the whole mid-IR spectral range. This talk will present an overview of our current achievements. References 1. M. Troccoli, "High power emission and single mode operation of quantum cascade lasers for industrial applications", J. Sel. Topics in Quantum Electron., 21 (6), 1-7 (2015). Invited Review. 2. Seungyong Jung, Aiting Jiang, Yifan Jiang, Karun Vijayraghavan, Xiaojun Wang, Mariano Troccoli, and Mikhail A. Belkin, "Broadly Tunable Monolithic Terahertz Quantum Cascade Laser Sources", Nature Comm. 5, 4267 (2014).. 3. Mariano Troccoli, Arkadiy Lyakh, Jenyu Fan, Xiaojun Wang, Richard Maulini, Alexei G Tsekoun, Rowel Go, C Kumar N Patel, "Long

  16. Optically pumped FIR lasers and their application in plasma diagnostics

    International Nuclear Information System (INIS)

    Bakos, J.S.

    1986-06-01

    The pysics and the construction of the far infrared lasers (FIRL) and of the infrared lasers pumping them are reviewed. The details of the construction, resonating and pumping systems, spectral and power characteristics of the FIRLs are discussed. Recently more than 1000 laser lines are known and used in the 27-80 mm wavelength range, but in many cases the laser kinetics are not fully understood, and some instability phenomena cannot be prevented. New nonlinear processes were found: two-photon pumping, hyper Raman laser tuning and relaxation phenomena. A broad application field, the plasma diagnostics by far infrared lasers is described. Scattering of infrared laser radiation can give new interesting information on the not understood effect of the anomalous transport in the high temperature plasma. (D.Gy.)

  17. Pulsed laser ablation of solids basics, theory and applications

    CERN Document Server

    Stafe, Mihai; Puscas, Niculae N

    2014-01-01

    The book introduces ‘the state of the art' of pulsed laser ablation and its applications. It is based on recent theoretical and experimental studies. The book reaches from the basics to advanced topics of pulsed laser ablation. Theoretical and experimental fundamental phenomena involved in pulsed laser ablation are discussed with respect to material properties, laser wavelength, fluence and intensity regime of the light absorbed linearly or non-linearly in the target material. The energy absorbed by the electrons leads to atom/molecule excitation, ionization and/or direct chemical bond breaking and is also transferred to the lattice leading to material heating and phase transitions. Experimental  non-invasive optical methods for analyzing these phenomena in real time are described. Theoretical models for pulsed laser ablation and phase transitions induced by laser beams and laser-vapour/plasma interaction during the plume expansion above the target are also presented. Calculations of the ablation speed and...

  18. Evaluation of 2.1μm DFB lasers for space applications

    Science.gov (United States)

    Barbero, J.; López, D.; Esquivias, I.; Tijero, J. M. G.; Fischer, M.; Roessner, K.; Koeth, J.; Zahir, M.

    2017-11-01

    This paper presents the results obtained in the frame of an ESA-funded project called "Screening and Preevaluation of Shortwave Infrared Laser Diode for Space Application" with the objective of verifying the maturity of state of the art SWIR DFB lasers at 2.1μm to be used for space applications (mainly based on the occultation measurement principle and spectroscopy). The paper focus on the functional and environmental evaluation test plan. It includes high precision characterization, mechanical test (vibration and SRS shocks), thermal cycling, gamma and proton radiation tests, life test and some details of the Destructive Physical Analysis performed. The electro-optical characterization includes measurements of the tuning capabilities of the laser both by current and by temperature, the wavelength stability and the optical power versus laser current.

  19. Fractional lasers in dermatology - Current status and recommendations

    Directory of Open Access Journals (Sweden)

    Apratim Goel

    2011-01-01

    Full Text Available Introduction: Fractional laser technology is a new emerging technology to improve scars, fine lines, dyspigmentation, striae and wrinkles. The technique is easy, safe to use and has been used effectively for several clinical and cosmetic indications in Indian skin. Devices: Different fractional laser machines, with different wavelengths, both ablative and non-ablative, are now available in India. A detailed understanding of the device being used is recommended. Indications: Common indications include resurfacing for acne, chickenpox and surgical scars, periorbital and perioral wrinkles, photoageing changes, facial dyschromias. The use of fractional lasers in stretch marks, melasma and other pigmentary conditions, dermatological conditions such as granuloma annulare has been reported. But further data are needed before adopting them for routine use in such conditions. Physician qualification: Any qualified dermatologist may administer fractional laser treatment. He/ she should possess a Master′s degree or diploma in dermatology and should have had specific hands-on training in lasers, either during postgraduation or later at a facility which routinely performs laser procedures under a competent dermatologist or plastic surgeon with experience and training in using lasers. Since parameters may vary with different systems, specific training tailored towards the concerned device at either the manufacturer′s facility or at another center using the machine is recommended. Facility: Fractional lasers can be used in the dermatologist′s minor procedure room for the above indications. Preoperative counseling and Informed consent: Detailed counseling with respect to the treatment, desired effects and possible postoperative complications should be provided to the patient. The patient should be provided brochures to study and also adequate opportunity to seek information. A detailed consent form needs to be completed by the patient. Consent form should

  20. Diagnostic and therapeutic applications of diode lasers and solid state lasers in medicine. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Jacques, S.L. [Texas Univ., Houston, TX (United States). Cancer Center; Welch, A.J. [Texas Univ., Austin, TX (United States); Motamedi, M. [Texas Univ., Galveston, TX (United States). Medical Branch; Rastegar, S. [Texas A and M Univ., College Station, TX (United States); Tittel, F. [Rice Univ., Houston, TX (United States); Esterowitz, L. [Naval Research Lab., Washington, DC (United States)

    1993-05-01

    The Texas Medical Center in Houston and the nearby UT Medical Branch at Galveston together constitute a major center of medical research activities. Laser applications in medicine are under development with the engineering assistance of the collaborating engineering enters at Rice University, UT-Austin, Texas A&M Univ. In addition, this collective is collaborating with the naval Research Laboratory, where new developments in laser design are underway, in order to transfer promising new laser technology rapidly into the medical environment.

  1. Diagnostic and therapeutic applications of diode lasers and solid state lasers in medicine. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Jacques, S.L. [Texas Univ., Houston, TX (United States). Cancer Center; Welch, A.J. [Texas Univ., Austin, TX (United States); Motamedi, M. [Texas Univ., Galveston, TX (United States). Medical Branch; Rastegar, S. [Texas A and M Univ., College Station, TX (United States); Tittel, F. [Rice Univ., Houston, TX (United States); Esterowitz, L. [Naval Research Lab., Washington, DC (United States)

    1992-05-01

    The Texas Medical Center in Houston and the nearby UT Medical Branch at Galveston together constitute a major center of medical research activities. Laser applications in medicine are under development with the engineering assistance of the colloborating engineering centers at Rice University, UT-Austin, and Texas A&M Univ. In addition, this collective is collaborating with the Naval Research Laboratory, where new developments in laser design are underway, in order to transfer promising new laser technology rapidly into the medical environment.

  2. Diagnostic and therapeutic applications of diode lasers and solid state lasers in medicine

    Energy Technology Data Exchange (ETDEWEB)

    Jacques, S.L. (Texas Univ., Houston, TX (United States). Cancer Center); Welch, A.J. (Texas Univ., Austin, TX (United States)); Motamedi, M. (Texas Univ., Galveston, TX (United States). Medical Branch); Rastegar, S. (Texas A and M Univ., College Station, TX (United States)); Tittel, F. (Rice Univ., Houston, TX (United States)); Esterowitz, L. (Naval Research Lab., Washington, DC (United States))

    1992-05-01

    The Texas Medical Center in Houston and the nearby UT Medical Branch at Galveston together constitute a major center of medical research activities. Laser applications in medicine are under development with the engineering assistance of the colloborating engineering centers at Rice University, UT-Austin, and Texas A M Univ. In addition, this collective is collaborating with the Naval Research Laboratory, where new developments in laser design are underway, in order to transfer promising new laser technology rapidly into the medical environment.

  3. Fiber Optic Cables for Transmission of High-Power Laser Pulses in Spaceflight Applications

    Science.gov (United States)

    Thomes, W. J., Jr.; Ott, M. N.; Chuska, R. F.; Switzer, R. C.; Blair, D. E.

    2010-01-01

    Lasers with high peak power pulses are commonly used in spaceflight missions for a wide range of applications, from LIDAR systems to optical communications. Due to the high optical power needed, the laser has to be located on the exterior of the satellite or coupled through a series of free space optics. This presents challenges for thermal management, radiation resistance, and mechanical design. Future applications will require multiple lasers located close together, which further complicates the design. Coupling the laser energy into a fiber optic cable allows the laser to be relocated to a more favorable position on the spacecraft. Typical fiber optic termination procedures are not sufficient for injection of these high-power laser pulses without catastrophic damage to the fiber endface. In the current study, we will review the causes of fiber damage during high-power injection and discuss our new manufacturing procedures that overcome these issues to permit fiber use with high reliability in these applications. We will also discuss the proper methods for launching the laser pulses into the fiber to avoid damage and how this is being implemented for current spaceflight missions.

  4. Fiber optic cables for transmission of high-power laser pulses in spaceflight applications

    Science.gov (United States)

    Thomes, W. J.; Ott, M. N.; Chuska, R. F.; Switzer, R. C.; Blair, D. E.

    2017-11-01

    Lasers with high peak power pulses are commonly used in spaceflight missions for a wide range of applications, from LIDAR systems to optical communications. Due to the high optical power needed, the laser has to be located on the exterior of the satellite or coupled through a series of free space optics. This presents challenges for thermal management, radiation resistance, and mechanical design. Future applications will require multiple lasers located close together, which further complicates the design. Coupling the laser energy into a fiber optic cable allows the laser to be relocated to a more favorable position on the spacecraft. Typical fiber optic termination procedures are not sufficient for injection of these high-power laser pulses without catastrophic damage to the fiber endface. In the current study, we will review the causes of fiber damage during high-power injection and discuss our new manufacturing procedures that overcome these issues to permit fiber use with high reliability in these applications. We will also discuss the proper methods for launching the laser pulses into the fiber to avoid damage and how this is being implemented for current spaceflight missions.

  5. Characteristics and Applications of Spatiotemporally Focused Femtosecond Laser Pulses

    Directory of Open Access Journals (Sweden)

    Chenrui Jing

    2016-12-01

    Full Text Available Simultaneous spatial and temporal focusing (SSTF of femtosecond laser pulses gives rise to strong suppression of nonlinear self-focusing during the propagation of the femtosecond laser beam. In this paper, we begin with an introduction of the principle of SSTF, followed by a review of our recent experimental results on the characterization and application of the spatiotemporally focused pulses for femtosecond laser micromachining. Finally, we summarize all of the results and give a future perspective of this technique.

  6. Development of Laser Application Technology for Stable Isotope Production

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Do Young; Ko, Kwang Hoon; Kwon, Duck Hee [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)] (and others)

    2007-04-15

    Tl-203 is used as a source material to produce Tl-201 radioisotope which is produced in a cyclotron by irradiating the enriched Tl-203 target. Tl-201 is a radiopharmaceutical for SPECT (single photon emission computerized tomography) to diagnose heart diseases and tumors. This Project aim to develop laser application technology to product stable isotopes such as Tl-203, Yb-168, and Yb-176. For this, photoion extraction device, atomic beam generator, dye lasers, and high power IR lasers are developed.

  7. IL 2 Laser Accelerated Protons and Electrons in Medical Applications

    International Nuclear Information System (INIS)

    Ceccotti, T.; Martin, Ph.; Giulietti, A.

    2010-01-01

    Charged particle acceleration through laser-matter interaction is a well-known phenomenon since long-time. T 3 (Table Top Terawatt) lasers reaching, and sometimes, getting over intensities around 10 20 W/cm 2 , allows producing particle beams in the so-called 'relativistic' regime (as accelerated electrons velocity is close to c) showing outstanding features in terms of energy, brightness and short burst duration. As a consequence they are interesting for a large spread of applications. Undoubtedly, the research in this field is stimulated to a large extent by the hope of using laser produced high energy particles for medical purposes. In particular, laser driven sources appear as a promising alternative to classical accelerator sources for two kinds of cancer treatments: the proton beam therapy (PBT) and the intra-operative radiation therapy (IORT). In this talk, we will focus on the main physical acceleration mechanisms for protons and electrons and we will review the main features and the application domain of PBT and IORT. We will present the potential advantages offered by laser-based sources as well as the progress requested to possibly substitute traditional by laser-based sources. More than 50.000 patients have been already treated with PBT since the work of Wilson about 60 years ago, which suggested using fast proton for radiotherapy. Due to the typical energy loss of protons traversing matter, the very biggest part of proton energy is actually delivered in a confined volume at a depth proportional to their energy. It is therefore possible to precisely aim at the tumor location without damaging the tissues situated just after the Bragg peak, on the contrary of standard x-ray radiation treatment. This results in fewer and milder side effects for the patient and in a quite lower relapsing rate making PBT the therapy of choice for pediatric cancer diseases and for those tumors whose location is close to vital organs. The usual required energy of

  8. A NASA discovery has current applications in orthopaedics.

    Science.gov (United States)

    Cotler, Howard B

    2015-01-01

    Low-level laser therapy (LLLT) has been actively used for nearly 40 yr, during which time it has been known to reduce pain, inflammation, and edema. It also has the ability to promote healing of wounds, including deep tissues and nerves, and prevent tissue damage through cell death. Much of the landmark research was done by the National Aeronautics and Space Administration (NASA), and these studies provided a springboard for many additional basic science studies. Few current clinical studies in orthopaedics have been performed, yet only in the past few years have basic science studies outlined the mechanisms of the effect of LLLT on the cell and subsequently the organism. This article reviews the basic science of LLLT, gives a historical perspective, and explains how it works, exposes the controversies and complications, and shows the new immediately applicable information in orthopaedics.

  9. Diode Lasers used in Plastic Welding and Selective Laser Soldering - Applications and Products

    Science.gov (United States)

    Reinl, S.

    Aside from conventional welding methods, laser welding of plastics has established itself as a proven bonding method. The component-conserving and clean process offers numerous advantages and enables welding of sensitive assemblies in automotive, electronic, medical, human care, food packaging and consumer electronics markets. Diode lasers are established since years within plastic welding applications. Also, soft soldering using laser radiation is becoming more and more significant in the field of direct diode laser applications. Fast power controllability combined with a contactless temperature measurement to minimize thermal damage make the diode laser an ideal tool for this application. These advantages come in to full effect when soldering of increasingly small parts in temperature sensitive environments is necessary.

  10. Nonablative lasers and nonlaser systems in dermatology: Current status

    Directory of Open Access Journals (Sweden)

    Mukta Sachdev

    2011-01-01

    Full Text Available Nonablative lasers and nonlaser systems are newer systems used for skin rejuvenation, tightening, body sculpting, and scar remodeling. Devices: Different technologies such as lasers, Intense Pulsed Light (IPL, and radiofrequency have been introduced. Most nonablative laser systems emit light within the infrared portion of the electromagnetic spectrum (1000-1500nm. At these wavelengths, absorption by superficial water containing tissue is relatively weak, thereby effecting deeper tissue penetration. A detailed understanding of the device being used is recommended. Indications: Nonablative technology have been used for several indications such as skin tightening, periorbital tissue tightening, treatment of nasolabial lines and jowl, body sculpting/remodeling, cellulite reduction, scar revision and remodeling and for the treatment of photodamaged skin. Facility: Nonablative laser and light modalities can be carried out in a physician treatment room or hospital setting or a nursing home with a small operation theater. Preoperative counseling and informed consent: The dermatologic consultation should include detailed assessment of the patient′s skin condition and skin type. An informed consent is mandatory to protect the rights of the patient as well as the practitioner. All patients must have carefully taken preoperative and postoperative pictures. Choice of the device and parameters: Depends on the indication, the area to be treated, the acceptable downtime for the desired correction, and to an extent the skin color. Anesthesia: These lasers are mostly pain-free and tolerated well by patients but may require topical anesthesia. In most cases, topical cooling and numbing using icepacks is sufficient, even in an apprehensive patient. Postoperative care: The nonablative lasers, light sources and radiofrequency systems are safe, even in darker skin types, and postoperative care is minimal. Proper postoperative care is important in avoiding

  11. Nonablative lasers and nonlaser systems in dermatology: current status.

    Science.gov (United States)

    Sachdev, Mukta; Hameed, Sunaina; Mysore, Venkataram

    2011-01-01

    Nonablative lasers and nonlaser systems are newer systems used for skin rejuvenation, tightening, body sculpting, and scar remodeling. Different technologies such as lasers, Intense Pulsed Light (IPL), and radiofrequency have been introduced. Most nonablative laser systems emit light within the infrared portion of the electromagnetic spectrum (1000-1500 nm). At these wavelengths, absorption by superficial water containing tissue is relatively weak, thereby effecting deeper tissue penetration. A detailed understanding of the device being used is recommended. Nonablative technology have been used for several indications such as skin tightening, periorbital tissue tightening, treatment of nasolabial lines and jowl, body sculpting/remodeling, cellulite reduction, scar revision and remodeling and for the treatment of photodamaged skin. Nonablative laser and light modalities can be carried out in a physician treatment room or hospital setting or a nursing home with a small operation theater. The dermatologic consultation should include detailed assessment of the patient's skin condition and skin type. An informed consent is mandatory to protect the rights of the patient as well as the practitioner. All patients must have carefully taken preoperative and postoperative pictures. Depends on the indication, the area to be treated, the acceptable downtime for the desired correction, and to an extent the skin color. These lasers are mostly pain-free and tolerated well by patients but may require topical anesthesia. In most cases, topical cooling and numbing using icepacks is sufficient, even in an apprehensive patient. The nonablative lasers, light sources and radiofrequency systems are safe, even in darker skin types, and postoperative care is minimal. Proper postoperative care is important in avoiding complications. Post-treatment edema and redness settle in a few hours to a few days. Postoperative sun avoidance and use of sunscreen is mandatory.

  12. Laser reduced graphene for supercapacitor applications

    Science.gov (United States)

    Yang, Dongfang; Bock, Christina

    2017-01-01

    Graphene was prepared by excimer laser irradiation reduction of graphite oxide dissolved in an aqueous solution at different laser energies and irradiation time. The morphologies and structure of the laser reduced graphene were characterized using scanning electron microscopy, low angle X-ray diffraction (XRD) and X-ray photoelectron spectroscopy. The XRD results confirm that the deoxygenation of the graphite oxide sheets occurred almost completely for all laser irradiation conditions used. The graphene fabricated by laser irradiation reduction appears to be randomly aggregated, crumpled, disordered and small sheet solid material. The total amount of oxygen functional groups reduced significantly and the CC/CO intensity ratio increased, however, the atomic percentages of the Cdbnd O double bond were increased after laser reduction. The laser reduced graphene was used as the electrode active material for supercapacitors and its specific capacitance was evaluated in a two electrode cell in either a 0.5 M Na2SO4 aqueous or a 1 M Tetraethylammoniumtetrafluoroborate acetonitrile based electrolyte. The specific capacitance of the laser fabricated graphene was found to depend on the energy and irradiation time of the laser. The highest specific capacitance was determined to be 141 F/g at 1.04 A/g and 84 F/g at 1.46 A/g in the aqueous and ACN electrolytes, respectively.

  13. 42. Science week: Laser Science and applications, Aleppo (SY), 2-4 Nov 2002, Book three: Laser applications

    International Nuclear Information System (INIS)

    2005-01-01

    This publication includes the papers presented at the 42nd science week of the Supreme Council of Sciences, held in Aleppo (Syria) from 2-4 November 2002. This proceedings is published in three books covering laser science and applications and in particular on material studies and medical uses. Part two covers medical applications, Part three on applications of laser in material sciences, while Part one is for contents and the proceedings program

  14. Current use and potential of additive manufacturing for optical applications

    Science.gov (United States)

    Brunelle, Matthew; Ferralli, Ian; Whitsitt, Rebecca; Medicus, Kate

    2017-10-01

    Additive manufacturing, or 3D printing, has become widely used in recent years for the creation of both prototype and end-use parts. Because the parts are created in a layer-by-layer manner, the flexibility of additive manufacturing is unparalleled and has opened the design space to enable features like undercuts and internal channels which cannot exist on traditional, subtractively manufactured parts. This flexibility can also be leveraged for optical applications. This paper outlines some of the current uses of 3D printing in the optical manufacturing process at Optimax. Several materials and additive technologies are utilized, including polymer printing through fused deposition modeling, which creates parts by depositing a softened thermoplastic filament in a layerwise fashion. Stereolithography, which uses light to cure layers of a photopolymer resin, will also be discussed. These technologies are used to manufacture functional prototypes, fixtures, sealed housings, and other components. Additionally, metal printing through selective laser melting, which uses a laser to melt metal powder layers into a dense solid, will be discussed due to the potential to manufacture thermally stable opticalmechanical assembly frameworks and functional optics. Examples of several additively manufactured optical components will be shown.

  15. The development and application of high energy laser protective material

    Science.gov (United States)

    Zhao, Xinying; Hu, Yihua; Zhao, Yizheng

    2016-03-01

    With the emergence of strong light source, laser weapons in the modern war, the threat of damage to the photoelectric sensor and the human eye, the laser protection technology has begun to be paid attention to and widespread concern. In the laser protective materials, we can divide it into the protective material based on the principle of linear optics and the protective material based on the principle of nonlinear optics. In this paper, two different mechanisms of laser protective materials are introduced, and their development and application are reviewed.

  16. Laser Science and its Applications in Prosthetic Rehabilitation

    Science.gov (United States)

    Gounder, Revathy; Gounder, Srinivasan

    2016-01-01

    The minimal invasive nature of lasers, with quick tissue response and healing has made them a very attractive technology in various fields of dentistry which serves as a tool to create a better result than ever before. The rapid development of lasers and their wavelengths with variety of applications on soft and hard tissues may continue to have major impact on the scope and practice in prosthetic dentistry. The purpose of this article is to make every clinician familiar with the fundamentals of lasers and different laser systems to incorporate into their clinical practices. PMID:28491254

  17. Current applications of graphene oxide in nanomedicine

    Directory of Open Access Journals (Sweden)

    Wu SY

    2015-08-01

    Full Text Available Si-Ying Wu, Seong Soo A An, John Hulme Department of Bionanotechnology, Gachon Medical Research Institute, Gachon University, Sungnamsi, Republic of Korea Abstract: Graphene has attracted the attention of the entire scientific community due to its unique mechanical and electrochemical, electronic, biomaterial, and chemical properties. The water-soluble derivative of graphene, graphene oxide, is highly prized and continues to be intensely investigated by scientists around the world. This review seeks to provide an overview of the currents applications of graphene oxide in nanomedicine, focusing on delivery systems, tissue engineering, cancer therapies, imaging, and cytotoxicity, together with a short discussion on the difficulties and the trends for future research regarding this amazing material. Keywords: imaging, green, cancer, therapy, diagnostics, antibacterial, cytotoxicity, contrast agent, biofunctionalization

  18. Targeted alpha therapy: Applications and current status

    Energy Technology Data Exchange (ETDEWEB)

    Bruchertseifer, Frank, E-mail: frank.bruchertseifer@ec.europa.eu [European Commission, Joint Research Centre, Karlsruhe (Germany)

    2017-07-01

    Full text: The field of targeted alpha therapy has been developed rapidly in the last decade. Besides {sup 223}Ra, {sup 211}At and {sup 212}Pb/{sup 212}Bi the alpha emitters {sup 225}Ac and {sup 213}Bi are promising therapeutic radionuclides for application in targeted alpha therapy of cancer and infectious diseases. The presentation will give a short overview about the current clinical treatments with alpha emitting radionuclides and will place an emphasis on the most promising clinical testing of peptides and antibodies labelled with {sup 225}Ac and {sup 213}Bi for treatment of metastatic castration-resistant prostate cancer patients with glioma and glioblastoma multiform, PSMA-positive tumor phenotype and bladder carcinoma in situ. (author)

  19. Laser applications in nuclear power plants

    Indian Academy of Sciences (India)

    2014-01-09

    Jan 9, 2014 ... At NPCIL, we have used laser techniques to cut stainless steel sheets up to 14 mm thickness and stainless steel weld up to a depth of 3 mm. This remotely operable laser system has been engineered for its robustness with proper fixtures and tooling for various material processing operations on industrial ...

  20. Laser physics and a review of laser applications in dentistry for children.

    Science.gov (United States)

    Martens, L C

    2011-04-01

    The aim of this introduction to this special laser issue is to describe some basic laser physics and to delineate the potential of laser-assisted dentistry in children. A brief review of the available laser literature was performed within the scope of paediatric dentistry. Attention was paid to soft tissue surgery, caries prevention and diagnosis, cavity preparation, comfort of the patient, effect on bacteria, long term pulpal vitality, endodontics in primary teeth, dental traumatology and low level laser therapy. Although there is a lack of sufficient evidence taking into account the highest standards for evidence-based dentistry, it is clear that laser application in a number of different aetiologies for soft tissue surgery in children has proven to be successful. Lasers provide a refined diagnosis of caries combined with the appropriate preventive adhesive dentistry after cavity preparation. This will further lead to a new wave of micro-dentistry based on 'filling without drilling'. It has become clear from a review of the literature that specific laser applications in paediatric dentistry have gained increasing importance. It can be concluded that children should be considered as amongst the first patients for receiving laser-assisted dentistry.

  1. The application of diode laser in the treatment of oral soft tissues lesions. A literature review.

    Science.gov (United States)

    Ortega-Concepción, Daniel; Cano-Durán, Jorge A; Peña-Cardelles, Juan-Francisco; Paredes-Rodríguez, Víctor-Manuel; González-Serrano, José; López-Quiles, Juan

    2017-07-01

    Since its appearance in the dental area, the laser has become a treatment of choice in the removal of lesions in the oral soft tissues, due to the numerous advantages they offer, being one of the most used currently the diode laser. The aim of this review was to determine the efficacy and predictability of diode laser as a treatment of soft tissue injuries compared to other surgical methods. A literature review of articles published in PubMed/MEDLINE, Scopus and the Cochrane Library databases between 2007 and 2017 was performed. "Diode laser", "soft tissue", "oral cavity" and "oral surgery" were employed for the search strategy. Only articles published English or Spanish were selected. The diode laser is a minimally invasive technology that offers great advantages, superior to those of the conventional scalpel, such as reduction of bleeding, inflammation and the lower probability of scars. Its effectiveness is comparable to that of other types of lasers, in addition to being an option of lower cost and greater ease of use. Its application in the soft tissues has been evaluated, being a safe and effective method for the excision of lesions like fibromas, epulis fissuratum and the accomplishment of frenectomies. The diode laser can be used with very good results for the removal of lesions in soft tissues, being used in small exophytic lesions due to their easy application, adequate coagulation, no need to suture and the slightest inflammation and pain. Key words: Diode laser, soft tissues, oral cavity, oral surgery.

  2. A Multi-Wavelength IR Laser for Space Applications

    Science.gov (United States)

    Li, Steven X.; Yu, Anthony W.; Sun, Xiaoli; Fahey, Molly E.; Numata, Kenji; Krainak, Michael A.

    2017-01-01

    We present a laser technology development with space flight heritage to generate laser wavelengths in the near- to mid-infrared (NIR to MIR) for space lidar applications. Integrating an optical parametric crystal to the LOLA (Lunar Orbiter Laser Altimeter) laser transmitter design affords selective laser wavelengths from NIR to MIR that are not easily obtainable from traditional diode pumped solid-state lasers. By replacing the output coupler of the LOLA laser with a properly designed parametric crystal, we successfully demonstrated a monolithic intra-cavity optical parametric oscillator (iOPO) laser based on all high technology readiness level (TRL) subsystems and components. Several desired wavelengths have been generated including 2.1 microns, 2.7 microns and 3.4 microns. This laser can also be used in trace-gas remote sensing, as many molecules possess their unique vibrational transitions in NIR to MIR wavelength region, as well as in time-of-flight mass spectrometer where desorption of samples using MIR laser wavelengths have been successfully demonstrated.

  3. High-power laser sources for industry and their applications

    Science.gov (United States)

    Bachmann, Friedrich

    2007-06-01

    Despite the invention and availability of a wide variety of laser sources, only very few types have made their way into the industrial use, which very often requires reliable three shift running, high uptime and low running costs. Over a long time the CO II gas laser has dominated the high power material processing area and still holds with 41.1 % the biggest market share in that field. The most modern, most reliable and most cost efficient type of CO II laser is the diffusion cooled slab configuration, which provides almost diffraction limited beam quality and is nowadays available in a power range up to 8 kW. The advantage of solid state lasers is that their radiation can be guided through optical fibers, but they suffered from high cost and low efficiency. The appearance of diode lasers as a very efficient and reliable pumping source, however, has boosted solid state laser technology. Not only the beam quality and efficiency of the classical rod design could be improved by replacing broadband lamps by monochromatic diode lasers but furthermore, because of the high brilliance of the diode lasers, new concepts as the thin disc and the fiber laser could be realized. Especially the higher efficiency, reducing the running cost in conjunction with improved beam quality makes the solid state lasers the tool of the future, whenever 3D applications are under consideration.

  4. Applications of high power lasers in the battlefield

    Science.gov (United States)

    Kalisky, Yehoshua

    2009-09-01

    Laser weapon is currently considered as tactical as well as strategic beam weapons, and is considered as a part of a general layered defense system against ballistic missiles and short-range rockets. This kind of weapon can disable or destroy military targets or incoming objects used by small groups of terrorists or countries, at the speed of light. Laser weapon is effective at long or short distances, owing to beam's unique characteristics such as narrow bandwidth, high brightness, coherent both in time and space, and it travels at the speed of light. Unlike kinetic weapon, laser weapon converts the energy stored in an electromagnetic laser beam into a large amount of heat aimed on a small area spot at the skin of the missile, usually close to the liquid fuel storage tank, warhead case or engine area, following by a temperature increase and finally-catastrophic failure by material ablation or melt. The usefulness of laser light as a weapon has been studied for decades but only in recent years became feasible. There are two types of lasers being used: gas lasers and solid state lasers, including fiber lasers. All these types of lasers will be discussed below.

  5. Absorption of laser plasma in competition with oscillation currents for a terahertz spectrum.

    Science.gov (United States)

    Li, Xiaolu; Bai, Ya; Li, Na; Liu, Peng

    2018-01-01

    We generate terahertz radiation in a supersonic jet of nitrogen molecules pumped by intense two-color laser pulses. The tuning of terahertz spectra from blue shift to red shift is observed by increasing laser power and stagnation pressure, and the red shift range is enlarged with the increased stagnation pressure. Our simulation reveals that the plasma absorption of the oscillation currents and expanded plasma column owing to increased laser intensity and gas number density are crucial factors in the recurrence of the red shift of terahertz spectra. The findings disclose the microscopic mechanism of terahertz radiation and present a controlling knob for the manipulation of a broadband terahertz spectrum from laser plasma.

  6. Applications of super - high intensity lasers in nuclear engineering

    International Nuclear Information System (INIS)

    Salomaa, R.; Hakola, A.; Santala, M.

    2007-01-01

    Laser-plasma interactions arising when a super intense ultrashort laser pulse impinges a solid target creates intense partly collimated and energy resolved photons, high energy electron and protons and neutrons. In addition the plasma plume can generate huge magnetic and electric fields. Also ultra short X-ray pulses are created. We have participated in some of such experiments at Rutherford and Max-Planck Institute and assessed the applications of such kind as laser-driven accelerators. This paper discusses applications in nuclear engineering (neutron sources, isotope separation, fast ignition and transmutation, etc). In particular the potential for extreme time resolution and to partial energy resolution are assessed

  7. High-intensity laser application in Orthodontics

    OpenAIRE

    Sant’Anna, Eduardo Franzotti; Araújo, Mônica Tirre de Souza; Nojima, Lincoln Issamu; Cunha, Amanda Carneiro da; Silveira, Bruno Lopes da; Marquezan, Mariana

    2017-01-01

    ABSTRACT Introduction: In dental practice, low-level laser therapy (LLLT) and high-intensity laser therapy (HILT) are mainly used for dental surgery and biostimulation therapy. Within the Orthodontic specialty, while LLLT has been widely used to treat pain associated with orthodontic movement, accelerate bone regeneration after rapid maxillary expansion, and enhance orthodontic tooth movement, HILT, in turn, has been seen as an alternative for addressing soft tissue complications associated ...

  8. Simulation of Laser Cooling and Trapping in Engineering Applications

    Science.gov (United States)

    Ramirez-Serrano, Jaime; Kohel, James; Thompson, Robert; Yu, Nan; Lunblad, Nathan

    2005-01-01

    on the wide range of applications and technology developments that can be tackled using cold atoms and light fields. From more precise atomic clocks and gravity sensors to the development of quantum computers, there will be a need to completely understand the whole ensemble of physical mechanisms that play a role in the development of such technologies. The code also permits the study of the dynamic and steady-state operations of technologies that use cold atoms. The physical characteristics of lasers and fields can be time-controlled to give a realistic simulation of the processes involved such that the design process can determine the best control features to use. It is expected that with the features incorporated into the code it will become a tool for the useful application of ultracold atoms in engineering applications. Currently, the software is being used for the analysis and understanding of simple experiments using cold atoms, and for the design of a modular compact source of cold atoms to be used in future research and development projects. The results so far indicate that the code is a useful design instrument that shows good agreement with experimental measurements (see figure), and a Windows-based user-friendly interface is also under development.

  9. Laser production and heating of plasma for MHD application

    Science.gov (United States)

    Jalufka, N. W.

    1988-01-01

    Experiments have been made on the production and heating of plasmas by the absorption of laser radiation. These experiments were performed to ascertain the feasibility of using laser-produced or laser-heated plasmas as the input for a magnetohydrodynamic (MHD) generator. Such a system would have a broad application as a laser-to-electricity energy converter for space power transmission. Experiments with a 100-J-pulsed CO2 laser were conducted to investigate the breakdown of argon gas by a high-intensity laser beam, the parameters (electron density and temperature) of the plasma produced, and the formation and propagation of laser-supported detonation (LSD) waves. Experiments were also carried out using a 1-J-pulsed CO2 laser to heat the plasma produced in a shock tube. The shock-tube hydrogen plasma reached electron densities of approximately 10 to the 17th/cu cm and electron temperatures of approximately 1 eV. Absorption of the CO2 laser beam by the plasma was measured, and up to approximately 100 percent absorption was observed. Measurements with a small MHD generator showed that the energy extraction efficiency could be very large with values up to 56 percent being measured.

  10. 42. Science week: Laser Science and applications, Aleppo (SY), 2-4 Nov 2002, Book two: Laser science and medical laser applications

    International Nuclear Information System (INIS)

    2005-01-01

    This publication includes the papers presented at the 42nd science week of the Supreme Council of Sciences, held in Aleppo (Syria) from 2-4 November 2002. This proceedings is published in three books covering laser science and applications and in particular on material studies and medical uses. Part two covers medical applications, Part three on applications of laser in material sciences, while Part one is for contents and the proceedings program

  11. The development of novel Ytterbium fiber lasers and their applications

    Science.gov (United States)

    Nie, Bai

    The aim of my Ph.D. research is to push the fundamental limits holding back the development of novel Yb fiber lasers with high pulse energy and short pulse duration. The purpose of developing these lasers is to use them for important applications such as multiphoton microscopy and laser-induced breakdown spectroscopy. My first project was to develop a short-pulse high-energy ultrafast fiber laser for multiphoton microscopy. To achieve high multiphoton efficiency and depth resolved tissue imaging, ultrashort pulse duration and high pulse energy are required. In order to achieve this, an all-normal dispersion cavity design was adopted. Output performances of the built lasers were investigated by varying several cavity parameters, such as pump laser power, fiber length and intra-cavity spectral filter bandwidth. It was found that the length of the fiber preceding the gain fiber is critical to the laser performance. Generally, the shorter the fiber is, the broader the output spectrum is. The more interesting parameter is the intra-cavity spectral filter bandwidth. Counter intuitively, laser cavities using narrower bandwidth spectral filters generated much broader spectra. It was also found that fiber lasers with very narrow spectral filters produced laser pulses with parabolic profile, which are referred to as self-similar pulses or similaritons. This type of pulse can avoid wave-breaking and is an optimal approach to generate pulses with high pulse energy and ultrashort pulse duration. With a 3nm intra-cavity spectral filter, output pulses with about 20 nJ pulse energy were produced and compressed to about 41 fs full-width-at-half-maximum (FWHM) pulse duration. Due to the loss in the compression device, the peak power of the compressed pulses is about 250 kW. It was the highest peak power generated from a fiber oscillator when this work was published. This laser was used for multiphoton microscopy on living tissues like Drosophila larva and fruit fly wings. Several

  12. Proposed Designs for a Gate-Controlled Lateral Current Injection Laser

    Science.gov (United States)

    Honey, David Alan

    High speed communications systems have experienced rapid growth due to the development of high performance photonic components. Hardware such as fiberoptics and semiconductor lasers have not only increased the data handling capabilities of these systems, they have also reduced the cost of owning and operating them. Improving the data transmission capabilities of the currently installed fiberoptic infrastructure is an important means of economically enhancing our communications capabilities. However, high speed optical data transmitters are a serious obstacle to future improvements in these systems. The high speed performance of direct modulation lasers lags far behind the present day capabilities of fiber and optical detectors. Gain compression and heating are the dominant phenomena keeping direct modulation lasers from achieving their predicted level of performance. Gate Controlled Lateral Current Injection (GCLCI) lasers use the field-effect of a transistors' gate to modulate a semiconductor laser. Our goal in this dissertation is to propose GCLCI laser designs and fabrication methods. The GCLCI laser combines the structure of a lateral current injection (LCI) laser with the gate of a modulation doped field effect transistor (MODFET). There are many published models predicting the performance of the GCLCI laser. While all of these models have some basis in experimentally observed effects, none have resulted in a working GCLCI laser. We present an investigation of the critical issues surrounding GCLCI design and fabrication. We give an analysis of the tradeoffs between the MODFET's and the laser's conflicting gate-to-channel separation requirements. The MODFET needs to have the gate close to the quantum well in order to permit high speed modulation of current flow. The laser needs a thick layer on top of the quantum well active region in order to have adequate optical confinement. Our fabrication efforts failed to produce a working GCLCI laser. We did however get

  13. Physical aspects of laser applications to modern nuclear technologies

    International Nuclear Information System (INIS)

    Semerok, A.

    2001-11-01

    This report has been presented by the author to obtain his HDR (accreditation to supervise research). After a brief presentation of his domain of skills, of his education, of his professional experience, and his awards, the author gives an overview of his work performed in the field of laser applications to modern nuclear technologies. Notably, he reports experimental studies dealing with the following topics: radiation source for uranium isotope separation by MLIS method, laser isotope separation in atom vapour, laser plasma diagnostics in strong magnetic field, laser ablation-time of flight mass spectrometry for low uranium isotope ratio measurements, laser ablation-optical emission spectroscopy for surface analysis. The report is completed by many published scientific articles

  14. Spectral and temporal characteristics of target current and electromagnetic pulse induced by nanosecond laser ablation

    Science.gov (United States)

    Krása, J.; De Marco, M.; Cikhardt, J.; Pfeifer, M.; Velyhan, A.; Klír, D.; Řezáč, K.; Limpouch, J.; Krouský, E.; Dostál, J.; Ullschmied, J.; Dudžák, R.

    2017-06-01

    The current balancing the target charging and the emission of transient electromagnetic pulses (EMP) driven by the interaction of a focused 1.315 μm iodine 300 ps PALS laser with metallic and plastic targets were measured with the use of inductive probes. It is experimentally proven that the duration of return target currents and EMPs is much longer than the duration of laser-target interaction. The laser-produced plasma is active after the laser-target interaction. During this phase, the target acts as a virtual cathode and the plasma-target interface expands. A double exponential function is used in order to obtain the temporal characteristics of EMP. The rise time of EMPs fluctuates in the range up to a few tens of nanoseconds. Frequency spectra of EMP and target currents are modified by resonant frequencies of the interaction chamber.

  15. Development, production, and application of sealed-off copper and gold vapour lasers

    International Nuclear Information System (INIS)

    Lyabin, Nikolai A; Chursin, A D; Ugol'nikov, S A; Koroleva, M E; Kazaryan, M A

    2001-01-01

    An analysis is made of the current state of the art of scientific and engineering advances in the field of repetitively pulsed self-heating metal vapour (copper and gold) lasers based on industrial, sealed-off, high-temperature, metalceramic and metal-glass active elements. The major applications of these lasers are discussed. The energy, spatial, and time characteristics of the lasers and their dependence on the parameters and construction of the laser active elements (tubes) and optical resonators are considered. The ways for the development of new high-power industrial laser active elements with a high efficiency (1 - 2%) and a service life of 500 - 1000 h are analysed. An average output power of 80 W was realised with a laser tube 150 cm in length and 32 mm in diameter. When the pumping efficiency is improved by raising the voltage to 30 - 35 kV, this system in a copper vapour laser will allow an output power of 100 W to be obtained with one active element. The characteristics of industrial versions of metal vapour lasers manufactured in different countries are compared and discussed. (invited paper)

  16. Adaptive Tunable Laser Spectrometer for Space Applications

    Science.gov (United States)

    Flesch, Gregory; Keymeulen, Didier

    2010-01-01

    An architecture and process for the rapid prototyping and subsequent development of an adaptive tunable laser absorption spectrometer (TLS) are described. Our digital hardware/firmware/software platform is both reconfigurable at design time as well as autonomously adaptive in real-time for both post-integration and post-launch situations. The design expands the range of viable target environments and enhances tunable laser spectrometer performance in extreme and even unpredictable environments. Through rapid prototyping with a commercial RTOS/FPGA platform, we have implemented a fully operational tunable laser spectrometer (using a highly sensitive second harmonic technique). With this prototype, we have demonstrated autonomous real-time adaptivity in the lab with simulated extreme environments.

  17. Study of optical confinement of quantum cascade lasers and applications to detection

    International Nuclear Information System (INIS)

    Moreau, Virginie

    2008-01-01

    Quantum cascade lasers have been invented in 1994 and they have already established themselves as the semiconductor laser source of choice in the mid- and far-infrared ranges of the electromagnetic spectrum. As most molecules of chemical interest exhibit roto-vibrational transitions in these spectral ranges, quantum cascade lasers are especially suited for applications such as spectroscopy, trace gas detection or medical imaging. One of the current leading research axis targets the device optimization and miniaturization, with possible applications in detection microsystems. This PhD thesis work focused on the study and optimization of the vertical optical confinement in quantum cascade lasers featuring optical waveguides without top cladding layers. These structures are interesting because they are compatible with two different guiding mechanisms at the same time, i.e. surface-plasmons and air confinement. The study of the characteristics of the optical mode and of the electrical current dispersion allowed us to conceive original structures which open new perspectives, for instance in the domain of analytic detection in a fluidic environment. Furthermore, we have shown that the observation by near field microscopy is a powerful tool to characterize and understand quantum cascade lasers. Finally, we have laid the foundations for the optimization of miniaturized arrays of single-mode lasers based on photonic crystal technology. (author) [fr

  18. Laser dentistry: A new application of excimer laser in root canal therapy

    Energy Technology Data Exchange (ETDEWEB)

    Pini, R.; Salimbeni, R.; Vannini, M.; Barone, R.; Clauser, C. (Italian National Research Council, Firenze)

    1989-01-01

    We report the first study of the application of excimer lasers in dentistry for the treatment of dental root canals. High-energy ultraviolet (UV) radiation emitted by an XeCl excimer laser (308 nm) and delivered through suitable optical fibers can be used to remove residual organic tissue from the canals. To this aim, UV ablation thresholds of dental tissues have been measured, showing a preferential etching of infiltrated dentin in respect to healthy dentin, at laser fluences of 0.5-1.5 J/cm{sup 2}. This technique has been tested on extracted tooth samples, simulating a clinical procedure. Fibers of decreasing core diameters have been used to treat different sections of the root canal down to its apical portion, resulting in an effective, easy, and fast cleaning action. Possible advantages of excimer laser clinical applications in respect to usual procedures are also discussed.

  19. Future developments in laser technology and their applications

    International Nuclear Information System (INIS)

    Boyer, K.

    1979-01-01

    One of the many areas in which lasers are beginning to play an important role is that of chemistry. One application of great significance is the use of low average power tunable lasers as an analytical tool to measure or study reaction kinetics and products. The other application of equal or greater importance is the use of high average power tunable lasers as a manipulative tool to control or drive chemical reactions in industrial processes. Here the cost of photons is the most important factor and a new device called the 'Free Electron Laser' is under development which promises to reduce the photon cost to less than one dollar per pound of material, thus including a wide range of industrial products

  20. Coherent Doppler Laser Radar: Technology Development and Applications

    Science.gov (United States)

    Kavaya, Michael J.; Arnold, James E. (Technical Monitor)

    2000-01-01

    NASA's Marshall Space Flight Center has been investigating, developing, and applying coherent Doppler laser radar technology for over 30 years. These efforts have included the first wind measurement in 1967, the first airborne flights in 1972, the first airborne wind field mapping in 1981, and the first measurement of hurricane eyewall winds in 1998. A parallel effort at MSFC since 1982 has been the study, modeling and technology development for a space-based global wind measurement system. These endeavors to date have resulted in compact, robust, eyesafe lidars at 2 micron wavelength based on solid-state laser technology; in a factor of 6 volume reduction in near diffraction limited, space-qualifiable telescopes; in sophisticated airborne scanners with full platform motion subtraction; in local oscillator lasers capable of rapid tuning of 25 GHz for removal of relative laser radar to target velocities over a 25 km/s range; in performance prediction theory and simulations that have been validated experimentally; and in extensive field campaign experience. We have also begun efforts to dramatically improve the fundamental photon efficiency of the laser radar, to demonstrate advanced lower mass laser radar telescopes and scanners; to develop laser and laser radar system alignment maintenance technologies; and to greatly improve the electrical efficiency, cooling technique, and robustness of the pulsed laser. This coherent Doppler laser radar technology is suitable for high resolution, high accuracy wind mapping; for aerosol and cloud measurement; for Differential Absorption Lidar (DIAL) measurements of atmospheric and trace gases; for hard target range and velocity measurement; and for hard target vibration spectra measurement. It is also suitable for a number of aircraft operations applications such as clear air turbulence (CAT) detection; dangerous wind shear (microburst) detection; airspeed, angle of attack, and sideslip measurement; and fuel savings through

  1. Development of pulsed UV lasers and their application in laser spectroscopy

    International Nuclear Information System (INIS)

    De la Rosa, M I; Perez, C; Gruetzmacher, K; GarcIa, D; Bustillo, A

    2011-01-01

    The application of two-photon laser spectroscopy to plasma diagnostics requires tuneable UV-laser spectrometers providing: some mJ pulse energy at ns time scale with spectral quality close to Fourier Transform Limit, good pulse to pulse reproducibility and tuning linearity. We report about two different systems, a first laser specially optimized for the radiation at 243 nm, which is required for the 1S-2S two photon transition of atomic hydrogen, and a second one generating 205 nm suited for the transition 1S - 3S/3D.

  2. Biological applications of ultraviolet free-electron lasers

    International Nuclear Information System (INIS)

    Sutherland, J.C.

    1997-10-01

    This review examines the possibilities for biological research using the three ultraviolet free-electron lasers that are nearing operational status in the US. The projected operating characteristics of major interest in biological research of the free-electron lasers at Brookhaven National Laboratory, the Thomas Jefferson National Accelerator Facility, and Duke University are presented. Experimental applications in the areas of far- and vacuum ultraviolet photophysics and photochemistry, structural biology, environmental photobiology, and medical research are discussed and the prospects for advances in these areas, based upon the characteristics of the new ultraviolet free-electron lasers, are evaluated

  3. Applications of quantum cascade lasers in plasma diagnostics: a review

    Science.gov (United States)

    Röpcke, J.; Davies, P. B.; Lang, N.; Rousseau, A.; Welzel, S.

    2012-10-01

    Over the past few years mid-infrared absorption spectroscopy based on quantum cascade lasers operating over the region from 3 to 12 µm and called quantum cascade laser absorption spectroscopy or QCLAS has progressed considerably as a powerful diagnostic technique for in situ studies of the fundamental physics and chemistry of molecular plasmas. The increasing interest in processing plasmas containing hydrocarbons, fluorocarbons, nitrogen oxides and organo-silicon compounds has led to further applications of QCLAS because most of these compounds and their decomposition products are infrared active. QCLAS provides a means of determining the absolute concentrations of the ground states of stable and transient molecular species at time resolutions below a microsecond, which is of particular importance for the investigation of reaction kinetics and dynamics. Information about gas temperature and population densities can also be derived from QCLAS measurements. Since plasmas with molecular feed gases are used in many applications such as thin film deposition, semiconductor processing, surface activation and cleaning, and materials and waste treatment, this has stimulated the adaptation of QCLAS techniques to industrial requirements including the development of new diagnostic equipment. The recent availability of external cavity (EC) QCLs offers a further new option for multi-component detection. The aim of this paper is fourfold: (i) to briefly review spectroscopic issues arising from applying pulsed QCLs, (ii) to report on recent achievements in our understanding of molecular phenomena in plasmas and at surfaces, (iii) to describe the current status of industrial process monitoring in the mid-infrared and (iv) to discuss the potential of advanced instrumentation based on EC-QCLs for plasma diagnostics.

  4. Investigation of ferrofluid nanostructure by laser light scattering: medical applications

    Science.gov (United States)

    Nepomnyashchaya, E. K.; Velichko, E. N.; Pleshakov, I. V.; Aksenov, E. T.; Savchenko, E. A.

    2017-05-01

    Investigation of ferrofluids nanostructure by the laser light scattering technique is presented. Experimental studies involved measurements of the intensity of the laser radiation scattered by ferrofluid particles in interaction with albumin and under the influence of magnetic field. The effects of the magnitude and duration of the applied magnetic field on the formation of aggregates of magnetic nanoparticles and also the influence of magnetic fluids of different concentrations on blood proteins are considered. The findings may be useful for medical applications.

  5. Comparison Of Laser And Waterjet Systems For Industrial Applications

    Science.gov (United States)

    Mosavi, Reza K.

    1986-07-01

    High power laser systems and high pressure waterjet systems are both emerging as non-conventional cutting tools, capable of increasing productivity and quality in the manufacture of a great number of products employing diverse material. It is often a confusing issue for the manufacturing engineer or production manager to decide which system would be most suited for his applications. This paper is intended to provide some insights into the engineering and economic aspects of laser systems versus waterjet systems.

  6. Applications of robotics in laser welding

    NARCIS (Netherlands)

    de Graaf, M.W.; Aarts, Ronald G.K.M.; Katayama, Seiji

    2013-01-01

    This chapter describes how seam-tracking sensors can be integrated in a robotic laser welding system for automatic teaching of the seam trajectory as well as for correcting small errors from a pre-defined seam trajectory. Calibration procedures are required to derive accurate transformations of

  7. Laser applications in nuclear power plants

    Indian Academy of Sciences (India)

    Remote Tooling Section, Technology Development Group,. Nuclear Power Corporation of India Ltd., Mumbai 400 094, India. E-mail: dnsanyal@npcil.co.in. DOI: 10.1007/s12043-013-0650-0; ePublication: 9 January 2014. Abstract. This paper reports the state of the art of using a solid-state Nd:YAG laser for material.

  8. Progress in the applicability of plasma X-ray lasers

    Energy Technology Data Exchange (ETDEWEB)

    Kuehl, T., E-mail: T.Kuehl@gsi.de; Aurand, B.; Bagnoud, V.; Ecker, B.; Eisenbarth, U. [GSI (Germany); Guilbaud, O. [Universite Paris Sud (France); Fils, J.; Goette, S. [GSI (Germany); Habib, J. [Universite Paris Sud (France); Hochhaus, D.; Javorkova, D. [GSI (Germany); Neumayer, P. [Extreme Matter Institute, EMMI (Germany); Kazamias, S.; Pittman, M.; Ros, D. [Universite Paris Sud (France); Seres, J.; Spielmann, Ch. [Friedrich Schiller-University (Germany); Zielbauer, B.; Zimmer, D. [GSI (Germany)

    2010-02-15

    Proposed as satellite-based weapons during the 1980s, X-ray lasing was for a long time only achieved with enormous amounts of pump energy in either nuclear explosions or at kilojoule-class laser installations. During the last few years a tremendous development was achieved, most visible in the realisation of the FEL lasers at DESY and SLAC. As important for a wider applicability is the enormous reduction in pump energy for laser pumped plasma X-ray lasers, which now brings such devices into the range of applications for diagnostics and spectroscopy even in smaller laboratories. Main developments were the transient excitation scheme and the optimized pumping concepts. This paper concentrates on developments at the GSI Helmholtzcenter at Darmstadt aiming towards reliable X-ray laser sources in the range from 50 to several 100 eV. The main driving forces for the laser development at GSI are the possible application for the spectroscopy of Li-like ions in the storage ring ESR and the future storage ring NESR at FAIR, and the interest in novel plasma diagnostics.

  9. Instrumentation for low noise nanopore-based ionic current recording under laser illumination

    Science.gov (United States)

    Roelen, Zachary; Bustamante, José A.; Carlsen, Autumn; Baker-Murray, Aidan; Tabard-Cossa, Vincent

    2018-01-01

    We describe a nanopore-based optofluidic instrument capable of performing low-noise ionic current recordings of individual biomolecules under laser illumination. In such systems, simultaneous optical measurements generally introduce significant parasitic noise in the electrical signal, which can severely reduce the instrument sensitivity, critically hindering the monitoring of single-molecule events in the ionic current traces. Here, we present design rules and describe simple adjustments to the experimental setup to mitigate the different noise sources encountered when integrating optical components to an electrical nanopore system. In particular, we address the contributions to the electrical noise spectra from illuminating the nanopore during ionic current recording and mitigate those effects through control of the illumination source and the use of a PDMS layer on the SiNx membrane. We demonstrate the effectiveness of our noise minimization strategies by showing the detection of DNA translocation events during membrane illumination with a signal-to-noise ratio of ˜10 at 10 kHz bandwidth. The instrumental guidelines for noise minimization that we report are applicable to a wide range of nanopore-based optofluidic systems and offer the possibility of enhancing the quality of synchronous optical and electrical signals obtained during single-molecule nanopore-based analysis.

  10. Ultrafast fiber lasers based on self-similar pulse evolution: a review of current progress.

    Science.gov (United States)

    Chong, Andy; Wright, Logan G; Wise, Frank W

    2015-11-01

    Self-similar fiber oscillators are a relatively new class of mode-locked lasers. In these lasers, the self-similar evolution of a chirped parabolic pulse in normally-dispersive passive, active, or dispersion-decreasing fiber (DDF) is critical. In active (gain) fiber and DDF, the novel role of local nonlinear attraction makes the oscillators fundamentally different from any mode-locked lasers considered previously. In order to reconcile the spectral and temporal expansion of a pulse in the self-similar segment with the self-consistency required by a laser cavity's periodic boundary condition, several techniques have been applied. The result is a diverse range of fiber oscillators which demonstrate the exciting new design possibilities based on the self-similar model. Here, we review recent progress on self-similar oscillators both in passive and active fiber, and extensions of self-similar evolution for surpassing the limits of rare-earth gain media. We discuss some key remaining research questions and important future directions. Self-similar oscillators are capable of exceptional performance among ultrashort pulsed fiber lasers, and may be of key interest in the development of future ultrashort pulsed fiber lasers for medical imaging applications, as well as for low-noise fiber-based frequency combs. Their uniqueness among mode-locked lasers motivates study into their properties and behaviors and raises questions about how to understand mode-locked lasers more generally.

  11. High frequency alternating current chip nano calorimeter with laser heating.

    Science.gov (United States)

    Shoifet, E; Chua, Y Z; Huth, H; Schick, C

    2013-07-01

    Heat capacity spectroscopy at frequencies up to 100 kHz is commonly performed by thermal effusivity measurements applying the 3ω-technique. Here we show that AC-calorimetry using a thin film chip sensor allows for the measurement of frequency dependent heat capacity in the thin film limit up to about 1 MHz. Using films thinner than the thermal length of the thermal wave (~1 μm) at such frequencies is advantageous because it provides heat capacity alone and not in combination with other quantities like thermal conductivity, at least on a qualitative basis. The used calorimetric sensor and the sample are each less than 1 μm thick. For high frequency AC-calorimetry, high cooling rates at very small temperature differences are required. This is realized by minimizing the heated spot to the size of the on chip thermocouple (3 × 6 μm(2)). A modulated laser beam shaped and positioned by a glass fiber is used as the heat source. The device was used to measure the complex heat capacity in the vicinity of the dynamic glass transition (structural relaxation) of poly(methyl methacrylate). Combining different calorimeters finally provides data between 10(-3) Hz and 10(6) Hz. In this frequency range the dynamic glass transition shifts about 120 K.

  12. Application of laser ultrasonic non-destructive evaluation technique to additive manufacturing

    Science.gov (United States)

    Manzo, Anthony J.; Kenderian, Shant; Helvajian, Henry

    2016-04-01

    The change in properties of a propagating ultrasonic wave has been a mainstay characterization tool of the nondestructive evaluation (NDE) industry for identifying subsurface defects (e.g. damage). A variant of this concept could be applicable to 3D additive manufacturing where the existence of defects (e.g. pores) within a sub-layer could mark a product as non-qualifying. We have been exploring the utility of pulsed laser ultrasonic excitation coupled with CW laser heterodyne detection as an all optical scheme for characterizing sub surface layer properties. The all-optical approach permits a straight forward integration into a laser additive processing tool. To test the concept, we have developed an experimental system that generates pulsed ultrasonic waves (the probe) with high bandwidth (>30-200 microns) beams. Current tests include characterizing properties of spot weld joints between two thin stainless steel plates. The long term objective is to transition the technique into a laser additive manufacturing tool.

  13. Chromate conversion coatings and their current application

    Directory of Open Access Journals (Sweden)

    P. Pokorny

    2016-04-01

    Full Text Available This paper describes formation, composition and possible production technologies of application chromate coatings. Summation of common examples of applications of these coatings in corrosion protection of metals and alloys is provided. Individual chromate coatings are divided by their dominant anions either with CrVI or CrIII. Restrictions of chromate coatings with dominantly CrVI and related toxicity of hexavalent chromium is discussed in detail. In conclusion, examples of both chromium and other, alternative coatings are summed up. Application of these coatings as a protection for concrete hot-dip galvanized reinforcement is also reviewed.

  14. Applications of laser wakefield accelerator-based light sources

    International Nuclear Information System (INIS)

    Albert, Felicie; Thomas, Alec G. R.

    2016-01-01

    Laser-wakefield accelerators (LWFAs) were proposed more than three decades ago, and while they promise to deliver compact, high energy particle accelerators, they will also provide the scientific community with novel light sources. In a LWFA, where an intense laser pulse focused onto a plasma forms an electromagnetic wave in its wake, electrons can be trapped and are now routinely accelerated to GeV energies. From terahertz radiation to gamma-rays, this article reviews light sources from relativistic electrons produced by LWFAs, and discusses their potential applications. Betatron motion, Compton scattering and undulators respectively produce x-rays or gamma-rays by oscillating relativistic electrons in the wakefield behind the laser pulse, a counter-propagating laser field, or a magnetic undulator. Other LWFA-based light sources include bremsstrahlung and terahertz radiation. Here, we first evaluate the performance of each of these light sources, and compare them with more conventional approaches, including radio frequency accelerators or other laser-driven sources. We have then identified applications, which we discuss in details, in a broad range of fields: medical and biological applications, military, defense and industrial applications, and condensed matter and high energy density science.

  15. Extended-bandwidth frequency sweeps of a distributed feedback laser using combined injection current and temperature modulation

    Science.gov (United States)

    Hefferman, Gerald; Chen, Zhen; Wei, Tao

    2017-07-01

    This article details the generation of an extended-bandwidth frequency sweep using a single, communication grade distributed feedback (DFB) laser. The frequency sweep is generated using a two-step technique. In the first step, injection current modulation is employed as a means of varying the output frequency of a DFB laser over a bandwidth of 99.26 GHz. A digital optical phase lock loop is used to lock the frequency sweep speed during current modulation, resulting in a linear frequency chirp. In the second step, the temperature of the DFB laser is modulated, resulting in a shifted starting laser output frequency. A laser frequency chirp is again generated beginning at this shifted starting frequency, resulting in a frequency-shifted spectrum relative to the first recorded data. This process is then repeated across a range of starting temperatures, resulting in a series of partially overlapping, frequency-shifted spectra. These spectra are then aligned using cross-correlation and combined using averaging to form a single, broadband spectrum with a total bandwidth of 510.9 GHz. In order to investigate the utility of this technique, experimental testing was performed in which the approach was used as the swept-frequency source of a coherent optical frequency domain reflectometry system. This system was used to interrogate an optical fiber containing a 20 point, 1-mm pitch length fiber Bragg grating, corresponding to a period of 100 GHz. Using this technique, both the periodicity of the grating in the frequency domain and the individual reflector elements of the structure in the time domain were resolved, demonstrating the technique's potential as a method of extending the sweeping bandwidth of semiconductor lasers for frequency-based sensing applications.

  16. A laser application to nuclear astrophysics

    Energy Technology Data Exchange (ETDEWEB)

    Barbui, M.; Hagel, K.; Schmidt, K.; Zheng, H.; Burch, R.; Barbarino, M.; Natowitz, J. B. [Cyclotron Institute, Texas A and M University, 3366 TAMU, College Station, TX (United States); Bang, W.; Dyer, G.; Quevedo, H. J.; Gaul, E.; Bernstein, A. C.; Donovan, M. [Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, TX 78712 (United States); Bonasera, A. [Cyclotron Institute, Texas A and M University, 3366 TAMU, College Station, TX, U.S.A. and INFN- Laboratori Nazionali del Sud, via S.Sofia 62, 95125 Catania (Italy); Kimura, S. [Department of Physics, Università degli Studi di Milano, Via Celoria 16, 20133 Milano (Italy); Mazzocco, M. [Dipartimento di Fisica e Astronomia Università degli Studi di Padova and INFN Sezione di Padova, Via Marzolo 8, I-35131 Padova (Italy); Consoli, F.; De Angelis, R.; Andreoli, P. [Associazione Euratom-ENEA Sulla Fusione, Via Enrico Fermi 45, CP 65-00044 Frascati, Rome (Italy); Ditmire, T. [Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, TX, 78712 (United States)

    2014-05-09

    In the last decade, the availability in high-intensity laser beams capable of producing plasmas with ion energies large enough to induce nuclear reactions has opened new research paths in nuclear physics. We studied the reactions {sup 3}He(d,p){sup 4}He and d(d,n){sup 3}He at temperatures of few keV in a plasma, generated by the interaction of intense ultrafast laser pulses with molecular deuterium or deuterated-methane clusters mixed with {sup 3}He atoms. The yield of 14.7 MeV protons from the {sup 3}He(d,p){sup 4}He reaction was used to extract the astrophysical S factor. Results of the experiment performed at the Center for High Energy Density Science at The University of Texas at Austin will be presented.

  17. A laser application to nuclear astrophysics

    Science.gov (United States)

    Barbui, M.; Bang, W.; Bonasera, A.; Hagel, K.; Schmidt, K.; Zheng, H.; Burch, R.; Barbarino, M.; Natowitz, J. B.; Dyer, G.; Quevedo, H. J.; Gaul, E.; Bernstein, A. C.; Donovan, M.; Kimura, S.; Mazzocco, M.; Consoli, F.; De Angelis, R.; Andreoli, P.; Ditmire, T.

    2014-05-01

    In the last decade, the availability in high-intensity laser beams capable of producing plasmas with ion energies large enough to induce nuclear reactions has opened new research paths in nuclear physics. We studied the reactions 3He(d,p)4He and d(d,n)3He at temperatures of few keV in a plasma, generated by the interaction of intense ultrafast laser pulses with molecular deuterium or deuterated-methane clusters mixed with 3He atoms. The yield of 14.7 MeV protons from the 3He(d,p)4He reaction was used to extract the astrophysical S factor. Results of the experiment performed at the Center for High Energy Density Science at The University of Texas at Austin will be presented.

  18. Field Emitter Arrays for a Free Electron Laser Application

    CERN Document Server

    Shing-Bruce-Li, Kevin; Ganter, Romain; Gobrecht, Jens; Raguin, Jean Yves; Rivkin, Leonid; Wrulich, Albin F

    2004-01-01

    The development of a new electron gun with the lowest possible emittance would help reducing the total length and cost of a free electron laser. Field emitter arrays (FEAs) are an attractive technology for electron sources of ultra high brightness. Indeed, several thousands of microscopic tips can be deposited on a 1 mm diameter area. Electrons are then extracted by applying voltage to a first grid layer close to the tip apexes, the so called gate layer, and focused by a second grid layer one micrometer above the tips. The typical aperture diameter of the gate and the focusing layer is in the range of one micrometer. One challenge for such cathodes is to produce peak currents in the ampere range since the usual applications of FEAs require less than milliampere. Encouraging peak current performances have been obtained by applying voltage pulses at low frequency between gate and tips. In this paper we report on different tip materials available on the market: diamond FEAs from Extreme Devices Inc., ZrC single ...

  19. Clinical application of CO2 laser in periodontal treatment

    Science.gov (United States)

    Hayase, Yasuhiro

    1994-09-01

    CO2 lasers in particular are expected to have many dental applications because the CO2 laser beam exhibits strong tissue transpirative actions, such as instant coagulation, carbonization, and vaporization, and because its wavelength at 10.6 micrometers is fully absorbed by water so that the ability to make precise incisions with a high degree of safety is excellent, without damaging the deep tissues. However, clinical application of the CO2 laser has been slowed since a fiber which can conduct the laser beam to the oral cavity has only recently developed. This new fiber is an extremely flexible fiber with a minimum bending radius of 20 mm and utilizes pulse wave modes that have improved the handling characteristics in the mouth, and this has enabled us to apply the CO2 laser to a variety of periodontal conditions. The aim of this study was to evaluate the effectiveness of CO2 lasers for the early treatment of inflammation and pain relief of acute periodontitis, curettage of periodontal pockets, healing after excision of gingiva, and early improvement of gingivitis.

  20. Application of lap laser welding technology on stainless steel railway vehicles

    Science.gov (United States)

    Wang, Hongxiao; Wang, Chunsheng; He, Guangzhong; Li, Wei; Liu, Liguo

    2016-10-01

    Stainless steel railway vehicles with so many advantages, such as lightweight, antirust, low cost of maintenance and simple manufacturing process, so the production of high level stainless steel railway vehicles has become the development strategy of European, American and other developed nations. The current stainless steel railway vehicles body and structure are usually assembled by resistance spot welding process. The weak points of this process are the poor surface quality and bad airtight due to the pressure of electrodes. In this study, the partial penetration lap laser welding process was investigated to resolve the problems, by controlling the laser to stop at the second plate in the appropriate penetration. The lap laser welding joint of stainless steel railway vehicle car body with partial penetration has higher strength and surface quality than those of resistance spot welding joint. The biggest problem of lap laser welding technology is to find the balance of the strength and surface quality with different penetrations. The mechanism of overlap laser welding of stainless steel, mechanical tests, microstructure analysis, the optimization of welding parameters, analysis of fatigue performance, the design of laser welding stainless steel railway vehicles structure and the development of non-destructive testing technology were systematically studied before lap laser welding process to be applied in manufacture of railway vehicles. The results of the experiments and study show that high-quality surface state and higher fatigue strength can be achieved by the partial penetration overlap laser welding of the side panel structure, and the structure strength of the car body can be higher than the requirements of En12663, the standard of structural requirements of railway vehicles bodies. Our company has produced the stainless steel subway and high way railway vehicles by using overlap laser welding technology. The application of lap laser welding will be a big

  1. Laser desorption mass spectrometry for biomolecule detection and its applications

    Science.gov (United States)

    Winston Chen, C. H.; Sammartano, L. J.; Isola, N. R.; Allman, S. L.

    2001-08-01

    During the past few years, we developed and used laser desorption mass spectrometry for biomolecule detections. Matrix-assisted laser desorption/ionization (MALDI) was successfully used to detect DNA fragments with the size larger than 3000 base pairs. It was also successfully used to sequence DNA with both enzymatic and chemical degradation methods to produce DNA ladders. We also developed MALDI with fragmentation for direct DNA sequencing for short DNA probes. Since laser desorption mass spectrometry for DNA detection has the advantages of fast speed and no need of labeling, it has a great potential for molecular diagnosis for disease and person identification by DNA fingerprinting. We applied laser desorption mass spectrometry to succeed in the diagnosis of cystic fibrosis and several other nerve degenerative diseases such as Huntington's disease. We also succeeded in demonstrating DNA typing for forensic applications.

  2. Laser desorption mass spectrometry for biomolecule detection and its applications

    International Nuclear Information System (INIS)

    Winston Chen, C.H.; Allman, S.L.; Sammartano, L.J.; Isola, N.R.

    2001-01-01

    During the past few years, we developed and used laser desorption mass spectrometry for biomolecule detections. Matrix-assisted laser desorption/ionization (MALDI) was successfully used to detect DNA fragments with the size larger than 3000 base pairs. It was also successfully used to sequence DNA with both enzymatic and chemical degradation methods to produce DNA ladders. We also developed MALDI with fragmentation for direct DNA sequencing for short DNA probes. Since laser desorption mass spectrometry for DNA detection has the advantages of fast speed and no need of labeling, it has a great potential for molecular diagnosis for disease and person identification by DNA fingerprinting. We applied laser desorption mass spectrometry to succeed in the diagnosis of cystic fibrosis and several other nerve degenerative diseases such as Huntington's disease. We also succeeded in demonstrating DNA typing for forensic applications

  3. Current trend of robotics application in medical

    Science.gov (United States)

    Olanrewaju, O. A.; Faieza, A. A.; Syakirah, K.

    2013-06-01

    The applications of robotics in recent years has emerged beyond the field of manufacturing or industrial robots itself. Robotics applications are now widely used in medical, transport, underwater, entertainment and military sector. In medical field, these applications should be emphasized in view of the increasing challenges due to the variety of findings in the field of medicine which requires new inventions to ease work process. The objective of this review paper is to study and presents the past and on-going research in medical robotics with emphasis on rehabilitation (assistive care) and surgery robotics which are certainly the two main practical fields where robots application are commonly used presently. The study found that, rehabilitation and surgery robotics applications grow extensively with the finding of new invention, as well as research that is being undertaken and to be undertaken. The importance of medical robot in medical industry is intended to offer positive outcomes to assist human business through a complicated task that involves a long period, accuracy, focus and other routines that cannot be accomplished by human ability alone.

  4. Current trend of robotics application in medical

    International Nuclear Information System (INIS)

    Olanrewaju, O A; Faieza, A A; Syakirah, K

    2013-01-01

    The applications of robotics in recent years has emerged beyond the field of manufacturing or industrial robots itself. Robotics applications are now widely used in medical, transport, underwater, entertainment and military sector. In medical field, these applications should be emphasized in view of the increasing challenges due to the variety of findings in the field of medicine which requires new inventions to ease work process. The objective of this review paper is to study and presents the past and on-going research in medical robotics with emphasis on rehabilitation (assistive care) and surgery robotics which are certainly the two main practical fields where robots application are commonly used presently. The study found that, rehabilitation and surgery robotics applications grow extensively with the finding of new invention, as well as research that is being undertaken and to be undertaken. The importance of medical robot in medical industry is intended to offer positive outcomes to assist human business through a complicated task that involves a long period, accuracy, focus and other routines that cannot be accomplished by human ability alone.

  5. The status of high-power lasers and their applications in the battlefield

    Science.gov (United States)

    Kalisky, Yehoshua; Kalisky, Ofra

    2010-09-01

    We review the status and applications of a defensive weapon based on high-power lasers in the battlefield. The laser weapon is a novel concept that utilizes a high-power laser beam to traverse the distance into incoming objects at the speed of light and then destroys or disables it. Various types of lasers and configurations are discussed in this review, including gas lasers, solid state lasers, fiber lasers, and the free-electron laser. We discuss various configurations, such as an airborne laser, diode pumped crystals, and disk lasers as well as heat-capacity lasers. Recent applications of ultrafast solid state lasers for nonlethal or low-collateral-damage applications are also presented.

  6. Applications and performance of high power lasers and in the battlefield

    Science.gov (United States)

    Kalisky, Yehoshua; Kalisky, Ofra

    2011-12-01

    This paper reviews the status and applications of a defensive weapon based on high power lasers, in the battlefield. Laser weapon is a novel concept which utilizes high power laser beam to traverse the distance into incoming objects at a speed of light, and then, destroy or disable it. Various types of lasers and configurations will be discussed in this review including gas lasers, solid state lasers, fiber lasers and the free-electron laser. We will discuss various configurations such as airborne laser (ABL), diode pumped crystals and disk lasers as well as heat-capacity lasers. Recent applications of ultrafast solid state lasers for non-lethal or low collateral damage applications will be presented.

  7. Application of a compact diode pumped solid-state laser source for quantitative laser-induced breakdown spectroscopy analysis of steel

    Science.gov (United States)

    Tortschanoff, Andreas; Baumgart, Marcus; Kroupa, Gerhard

    2017-12-01

    Laser-induced breakdown spectroscopy (LIBS) technology holds the potential for onsite real-time measurements of steel products. However, for a mobile and robust LIBS measurement system, an adequate small and ruggedized laser source is a key requirement. In this contribution, we present tests with our compact high-power laser source, which, initially, was developed for ignition applications. The CTR HiPoLas® laser is a robust diode pumped solid-state laser with a passive Q-switch with dimensions of less than 10 cm3. The laser generates 2.5-ns pulses with 30 mJ at a maximum continuous repetition rate of about 30 Hz. Feasibility of LIBS experiments with the laser source was experimentally verified with steel samples. The results show that the laser with its current optical output parameters is very well-suited for LIBS measurements. We believe that the miniaturized laser presented here will enable very compact and robust portable high-performance LIBS systems.

  8. Highly-reliable laser diodes and modules for spaceborne applications

    Science.gov (United States)

    Deichsel, E.

    2017-11-01

    Laser applications become more and more interesting in contemporary missions such as earth observations or optical communication in space. One of these applications is light detection and ranging (LIDAR), which comprises huge scientific potential in future missions. The Nd:YAG solid-state laser of such a LIDAR system is optically pumped using 808nm emitting pump sources based on semiconductor laser-diodes in quasi-continuous wave (qcw) operation. Therefore reliable and efficient laser diodes with increased output powers are an important requirement for a spaceborne LIDAR-system. In the past, many tests were performed regarding the performance and life-time of such laser-diodes. There were also studies for spaceborne applications, but a test with long operation times at high powers and statistical relevance is pending. Other applications, such as science packages (e.g. Raman-spectroscopy) on planetary rovers require also reliable high-power light sources. Typically fiber-coupled laser diode modules are used for such applications. Besides high reliability and life-time, designs compatible to the harsh environmental conditions must be taken in account. Mechanical loads, such as shock or strong vibration are expected due to take-off or landing procedures. Many temperature cycles with high change rates and differences must be taken in account due to sun-shadow effects in planetary orbits. Cosmic radiation has strong impact on optical components and must also be taken in account. Last, a hermetic sealing must be considered, since vacuum can have disadvantageous effects on optoelectronics components.

  9. Design of a compact application-oriented free-electron laser

    Science.gov (United States)

    Chan, K. C. D.; Meier, K.; Nguyen, D.; Sheffield, R.; Wang, T. S.; Warren, R. W.; Wilson, W.; Young, L. M.

    The goal of the Advanced Free-Electron Laser Project at the Los Alamos National Laboratory is to demonstrate that a free-electron laser (FEL) suitable for industrial, medical, and research applications can be built. This FEL system should be efficient, compact, robust, and user-friendly. To achieve this goal, we have incorporated advanced components presently available. Electrons produced by a photoelectron source are accelerated to 20 MeV by a high-brightness accelerator. They are transported by an emittance-preserving beamline with permanent-magnet quadrupoles and dipoles. The electron beam has excellent instantaneous beam quality better than: 2.5 (pi) mm mrad in transverse emittance and 0.3 percent in energy spread at a Peak current up to 310 A. It is used to excite a FEL oscillator with a pulsed-current microwiggler. Including operation at higher harmonics, the laser wavelength extends from 3.7 to 0.4 microns.

  10. High speed, intermediate resolution, large area laser beam induced current imaging and laser scribing system for photovoltaic devices and modules

    Science.gov (United States)

    Phillips, Adam B.; Song, Zhaoning; DeWitt, Jonathan L.; Stone, Jon M.; Krantz, Patrick W.; Royston, John M.; Zeller, Ryan M.; Mapes, Meghan R.; Roland, Paul J.; Dorogi, Mark D.; Zafar, Syed; Faykosh, Gary T.; Ellingson, Randy J.; Heben, Michael J.

    2016-09-01

    We have developed a laser beam induced current imaging tool for photovoltaic devices and modules that utilizes diode pumped Q-switched lasers. Power densities on the order of one sun (100 mW/cm2) can be produced in a ˜40 μm spot size by operating the lasers at low diode current and high repetition rate. Using galvanostatically controlled mirrors in an overhead configuration and high speed data acquisition, large areas can be scanned in short times. As the beam is rastered, focus is maintained on a flat plane with an electronically controlled lens that is positioned in a coordinated fashion with the movements of the mirrors. The system can also be used in a scribing mode by increasing the diode current and decreasing the repetition rate. In either mode, the instrument can accommodate samples ranging in size from laboratory scale (few cm2) to full modules (1 m2). Customized LabVIEW programs were developed to control the components and acquire, display, and manipulate the data in imaging mode.

  11. The laser and its uses: 50 years after its invention; Le laser et ses applications: 50 ans apres son invention

    Energy Technology Data Exchange (ETDEWEB)

    Besnard, P. [FOTON/ENSSAT, CNRS, 22 - Lannion (France); Favennec, P.N. [APAST, 22 - Lannion (France)

    2011-07-01

    The laser, 50 years after its invention, has become a major player in modern technologies with its efficient partner the optical fiber. This book reviews the numerous applications of laser in diverse fields such as telecommunication, metrology, optical radar, surface treatment, medicine. The last chapter is dedicated to inertial fusion through the presentation of the Megajoule laser (LMJ) project

  12. Military applications of the laser weapons in the future battlefield

    Science.gov (United States)

    Celik, Hasan; Adana, Saban; Yahsi, Erhan

    2013-05-01

    Contemporary operating environment requires a wide range of tools to respond to a myriad of regular and irregular threats. Accordingly, conventional weapons do not suffice in some cases. As technology improves exponentially, the dominance of conventional weapons is slowly fading away by the advances in laser technology. This study first outlines the characteristics of laser weapons, then provides the military applications of them in land, maritime, air and space domains and finally exhibits implications for battlefield functions. This study concludes that any country that is seeking primacy in military terms must allocate extra time and resources to obtain this emerging technology. Since it seems that there are not adequate studies about the military applications and operational concepts of the laser weapons, this study tries to increase awareness about their potential advantages.

  13. Polymer Tribology: Current State and Applications

    Directory of Open Access Journals (Sweden)

    N.K. Myshkin

    2015-09-01

    Full Text Available Polymer tribology is based on the analysis of abrasion, adhesion, and fatigue of polymer materials in a friction contact. The structural features of polymers provide a variety of tribological applications of basic polymers mostly as matrices and fillers of composite materials. Recently polymer nanocomposites are used for making components of various tribosystems. A short review of polymer materials for tribosystems is presented. The main results of studies in friction and wear of polymers are given. Formation of the real area of contact is evaluated when taking account of polymer viscoelasticity and the effects of temperature and load in the contact. Adhesion of polymers and its part in friction transfer is considered. Various aspects of friction and wear tests of polymer materials for estimation of their characteristics, prediction of service life in different operational conditions are discussed. Practical examples of applications of polymer composites and nanocomposites in various branches of industry are given.

  14. Overview of current applications in plasma medicine

    Science.gov (United States)

    Ryan, Thomas P.; Stalder, Kenneth R.

    2017-02-01

    Plasma medicine is a rapidly growing field of treatment, with the number and type of medical applications growing annually, such as dentistry, cancer treatment, wound treatment, Antimicrobial (bacteria, biofilm, virus, fungus, prions), and surface sterilization. Work promoting muscle and blood vessel regeneration and osteointegration is being investigated. This review paper will cover the latest treatments using gas-based plasmas in medicine. Disinfection of water and new commercial systems will also be reviewed, as well as vaccine deactivation. With the rapid increase in new investigators, development of new devices and systems for treatment, and wider clinical applications, Plasma medicine is becoming a powerful tool in in the field of medicine. There are a wide range of Plasma sources that allows customization of the effect. These variations include frequency (DC to MHz), voltage capacity (kV), gas source (He, Ar; O2, N2, air, water vapor; combinations), direct/indirect target exposure, and water targets.

  15. NUCLEAR CARDIOLOGY, CURRENT APPLICATIONS IN CLINICAL-PRACTICE

    NARCIS (Netherlands)

    NIEMEYER, MG; VANDERWALL, EE; KUIJPER, AFM; CLEOPHAS, AT; PAUWELS, EKJ

    The clinical applications of nuclear cardiology have rapidly expanded since the introduction of suitable imaging cameras and readily applicable isotopes. The currently available methods can provide useful data on estimates of ventricular function and detection of myocardial ischemia for adequate

  16. Abstracts of the 5. International Conference on Lasers and their Applications

    International Nuclear Information System (INIS)

    1985-01-01

    New results have been presented in the fields of laser physics and laser applications including the development of new laser light sources, new laser frequencies in the UV and VUV spectral regions using anti-Stokes Raman scattering, nonlinear optical effects for the formation of ultrashort optical pulses, laser spectroscopy, collisionless multiphoton excitation processes using molecular beams, selective generation of free radicals by laser, laser applications in medicine, plasma diagnostics analysing X-ray spectra for studying laser fusion problems, coherence properties in phase-sampling interferometric techniques, and fundamental problems in quantum physics and nonlinear processes

  17. Vertical blow-up in a low-current, stored, laser-cooled ion beam

    CERN Document Server

    Madsen, N; Siegfried, L E; Hangst, J S; Nielsen, J

    2003-01-01

    Using a novel technique for real-time transverse beam profile diagnostics of a stored ion beam, we have observed the transverse size of a stored, laser-cooled ion beam. Earlier we observed that the density of the beam is independent of the beam current. At very low currents we observe an abrupt change in this behavior: the vertical beam size increases suddenly by about an order of magnitude. This observation implies a sudden change in the indirect vertical cooling mediated by intrabeam scattering. Our results have serious implications for the ultimate beam quality attainable by laser- cooling. (12 refs).

  18. Low-current, vertical blowup in a stored laser-cooled ion beam

    CERN Document Server

    Madsen, N; Nielsen, S; Siegfried, L E; Hangst, J S

    2001-01-01

    Using a novel technique for real-time transverse beam profile diagnostics of a stored ion beam, we have observed the transverse size of a stored laser-cooled ion beam. Earlier we observed that the density of the beam is independent of the beam current. At very low currents, we observe an abrupt change in this behavior: The vertical beam size increases suddenly by about an order of magnitude. This observation implies a sudden change in the indirect vertical cooling mediated by intrabeam scattering. Our results have serious implications for the ultimate beam quality attainable by laser cooling. (11 refs).

  19. INTERACTION OF LASER RADIATION WITH MATTER. LASER PLASMA: Generation of current pulses during polarisation of air ionised by ultraviolet laser radiation

    Science.gov (United States)

    Antipov, A. A.; Losev, Leonid L.; Soskov, V. I.

    1994-10-01

    Current pulses were generated in the course of the polarisation of air ionised by ultraviolet radiation. The dependence of the current pulse duration on the air pressure had a maximum. The amplitude of the pulses depended quadratically on the intensity of the laser radiation with the wavelength of 266 nm; the amplitude increased when the pressure was reduced in the range 10-760 Torr.

  20. Power transistor module for high current applications

    International Nuclear Information System (INIS)

    Cilyo, F.F.

    1975-01-01

    One of the parts needed for the control system of the 400-GeV accelerator at Fermilab was a power transistor with a safe operating area of 1800A at 50V, dc current gain of 100,000 and 20 kHz bandwidth. Since the commercially available discrete devices and power hybrid packages did not meet these requirements, a power transistor module was developed which performed satisfactorily. By connecting 13 power transistors in parallel, with due consideration for network and heat dissipation problems, and by driving these 13 with another power transistor, a super power transistor is made, having an equivalent current, power, and safe operating area capability of 13 transistors. For higher capabilities, additional modules can be conveniently added. (auth)

  1. Current urologic applications of digital imaging.

    Science.gov (United States)

    Kuo, R L; Preminger, G M

    2001-02-01

    One of the most significant developments in imaging technology has been the process of digitalization. By incorporating currently available digital imaging equipment into surgical practice, urologists can be assured of obtaining real-time video images with optimal clarity and detail. In addition, one can efficiently capture and store still images that are crisper and sharper than their analog counterparts. These factors greatly improve the diagnostic capabilities and organization of today's endourologist.

  2. New horizons in predictive toxicology: current status and application

    National Research Council Canada - National Science Library

    Wilson, A. G. E

    2012-01-01

    "In this comprehensive discussion of predictive toxicology and its applications, leading experts express their views on the technologies currently available and the potential for future developments...

  3. Application and the key technology on high power fiber-optic laser in laser weapon

    Science.gov (United States)

    Qu, Zhou; Li, Qiushi; Meng, Haihong; Sui, Xin; Zhang, Hongtao; Zhai, Xuhua

    2014-12-01

    The soft-killing laser weapon plays an important role in photoelectric defense technology. It can be used for photoelectric detection, search, blinding of photoelectric sensor and other devices on fire control and guidance devices, therefore it draws more and more attentions by many scholars. High power fiber-optic laser has many virtues such as small volume, simple structure, nimble handling, high efficiency, qualified light beam, easy thermal management, leading to blinding. Consequently, it may be used as the key device of soft-killing laser weapon. The present study introduced the development of high power fiber-optic laser and its main features. Meanwhile the key technology of large mode area (LMA) optical fiber design, the beam combination technology, double-clad fiber technology and pumping optical coupling technology was stated. The present study is aimed to design high doping LMA fiber, ensure single mode output by increasing core diameter and decrease NA. By means of reducing the spontaneous emission particle absorbed by fiber core and Increasing the power density in the optical fiber, the threshold power of nonlinear effect can increase, and the power of single fiber will be improved. Meantime, high power will be obtained by the beam combination technology. Application prospect of high power fiber laser in photoelectric defense technology was also set forth. Lastly, the present study explored the advantages of high power fiber laser in photoelectric defense technology.

  4. Epicardial Application Of Laser Energy In Vivo: Acute Arrhythmogenic Potential

    Science.gov (United States)

    Cohen, Mark H.; Ben-Shachar, Giora; Beder, Stanley D.; Sivakoff, Mark; Riemenschneider, Thomas A.

    1986-01-01

    In order to assess the effect of laser energy on the heart's rhythm, 7 newborn pigs each had 3 two-second applications of laser energy directly to the left ventricular epicardial surface. A quartz fiberoptic delivery system was used. All piglets (in all 21 applications) had ventricular arrhythmia induced. This varied from single premature ventricular contractions to sustained(112 seconds) ventricular tachycardia (6/7 piglets). The sustained ventri-cular tachycardia exhibited electrophysiologic criteria of a "re-entrant" mechanism. Fifteen minutes following lasing, programmed ventricular stimulation, a technique that indicates whether a substrate may be present for spontaneous re-entrant arrhythmias, showed induced arrhythmia in only 2/7 pigs, neither sustained. We conclude that epicardial application of laser energy frequently results in significant ventricular arrhythmia. This arrhythmia appears to be re-entrant in nature. Fowever, shortly following lasing, sustained arrhythmia could not be induced. Therefore, we feel that more knowledge about the arrhythmogenic potential of laser lesions is needed prior to wide-spread clinical application.

  5. Processor operated correlator with applications to laser Doppler signals

    DEFF Research Database (Denmark)

    Bisgaard, C.; Johnsen, B.; Hassager, Ole

    1984-01-01

    A 64-channel correlator is designed with application to the processing of laser Doppler anemometry signals in the range 200 Hz to 250 kHz. The correlator is processor operated to enable the consecutive sampling of 448 correlation functions at a rate up to 500 Hz. Software is described to identify...

  6. Novel Applications of High Speed Optical-Injection Locked Lasers

    Science.gov (United States)

    2010-07-31

    modulated vertical-cavity surface-emitting laser (VCSELs) are attractive candidates as cost-effective optical transmitters for metro -area networks (MANs...local area networks (LANs) and high-speed Ethernet applications. A directly modulated VCSEL is desirable because it is compact, cost-effective and

  7. Assiut Experience in the Application of Holmium Laser in Treatment ...

    African Journals Online (AJOL)

    Assiut Experience in the Application of Holmium Laser in Treatment of Ureteral Calculi in Adults. A.M. Abdel Lateef, A.E. Abdel Moniem, M.I. Taha, M.A. Shalaby. Abstract. Internal Optical Urethrotomy at the National Medical Center of Sanou Souro in Bobo-Dioulasso: Feasibility, Safety and Short-Term Results Objective To ...

  8. Application of laser radar to autonomous spacecraft landing

    Science.gov (United States)

    Gleichman, Kurt; Tchoryk, Peter, Jr.; Sampson, Robert E.

    1991-01-01

    This paper discusses the scenario of an autonomous landing like that required for the Mars Rover Sample Return Mission. An application of laser radar for conducting autonomous hazard detection and avoidance is discussed. A trade-study is performed to identify operational and implementation constraints as well as the state of the art in component technology.

  9. Application of laser-induced breakdown spectroscopy in carbon

    Indian Academy of Sciences (India)

    2014-07-18

    Jul 18, 2014 ... We propose the use of laser-induced breakdown spectroscopy (LIBS) analytical technique to detect carbon dioxide leaks to aid in the successful application of CCS. LIBS has a real-time monitoring capability and can be reliably used for the elemental and isotopic analysis of solid, liquid, and gas samples.

  10. Review of selective laser melting: Materials and applications

    International Nuclear Information System (INIS)

    Yap, C. Y.; Chua, C. K.; Liu, Z. H.; Zhang, D. Q.; Loh, L. E.; Sing, S. L.; Dong, Z. L.

    2015-01-01

    Selective Laser Melting (SLM) is a particular rapid prototyping, 3D printing, or Additive Manufacturing (AM) technique designed to use high power-density laser to melt and fuse metallic powders. A component is built by selectively melting and fusing powders within and between layers. The SLM technique is also commonly known as direct selective laser sintering, LaserCusing, and direct metal laser sintering, and this technique has been proven to produce near net-shape parts up to 99.9% relative density. This enables the process to build near full density functional parts and has viable economic benefits. Recent developments of fibre optics and high-power laser have also enabled SLM to process different metallic materials, such as copper, aluminium, and tungsten. Similarly, this has also opened up research opportunities in SLM of ceramic and composite materials. The review presents the SLM process and some of the common physical phenomena associated with this AM technology. It then focuses on the following areas: (a) applications of SLM materials and (b) mechanical properties of SLM parts achieved in research publications. The review is not meant to put a ceiling on the capabilities of the SLM process but to enable readers to have an overview on the material properties achieved by the SLM process so far. Trends in research of SLM are also elaborated in the last section

  11. Current potential of radionuclide applications in therapy

    International Nuclear Information System (INIS)

    Navratil, L.

    1987-01-01

    A review is presented of the proceedings of the 4th Boettstein Collegium held in June, 1986 in Wuerenlingen (CH), debating new possibilities in applying radionuclides in the therapy of malignant diseases. The new possibilities are open with the development of new biological carriers with high detection capacities, especially monoclonal antibodies. Therapeutical applications are characterized of some radionuclides, mainly 131 I and 123 I, and beta and alpha radionuclides are listed promising for therapeutical uses. Therapeutical prospects are also outlined for immunotherapy. (L.O.). 1 ref

  12. Sustainable Biomaterials: Current Trends, Challenges and Applications

    Directory of Open Access Journals (Sweden)

    Girish Kumar Gupta

    2015-12-01

    Full Text Available Biomaterials and sustainable resources are two complementary terms supporting the development of new sustainable emerging processes. In this context, many interdisciplinary approaches including biomass waste valorization and proper usage of green technologies, etc., were brought forward to tackle future challenges pertaining to declining fossil resources, energy conservation, and related environmental issues. The implementation of these approaches impels its potential effect on the economy of particular countries and also reduces unnecessary overburden on the environment. This contribution aims to provide an overview of some of the most recent trends, challenges, and applications in the field of biomaterials derived from sustainable resources.

  13. Laser-induced breakdown spectroscopy theory and applications

    CERN Document Server

    Perini, Umberto

    2014-01-01

    This book deals with the Laser-Induced Breakdown Spectroscopy (LIBS), a widely used atomic emission spectroscopy technique for elemental analysis of materials. It is based on the use of a high-power, short pulse laser excitation. The book is divided into two main sections: the first one concerning theoretical aspects of the technique, the second one describing the state of the art in applications of the technique in different scientific/technological areas. Numerous examples of state of the art applications provide the readers an almost complete scenario of the LIBS technique. The LIBS theoretical aspects are reviewed. The book helps the readers who are less familiar with the technique to understand the basic principles. Numerous examples of state of the art applications give an almost complete scenario of the LIBS technique potentiality. These examples of applications may have a strong impact on future industrial utilization. The authors made important contributions to the development of this field.

  14. Current oncologic applications of radiofrequency ablation therapies

    Science.gov (United States)

    Shah, Dhruvil R; Green, Sari; Elliot, Angelina; McGahan, John P; Khatri, Vijay P

    2013-01-01

    Radiofrequency ablation (RFA) uses high frequency alternating current to heat a volume of tissue around a needle electrode to induce focal coagulative necrosis with minimal injury to surrounding tissues. RFA can be performed via an open, laparoscopic, or image guided percutaneous approach and be performed under general or local anesthesia. Advances in delivery mechanisms, electrode designs, and higher power generators have increased the maximum volume that can be ablated, while maximizing oncological outcomes. In general, RFA is used to control local tumor growth, prevent recurrence, palliate symptoms, and improve survival in a subset of patients that are not candidates for surgical resection. It’s equivalence to surgical resection has yet to be proven in large randomized control trials. Currently, the use of RFA has been well described as a primary or adjuvant treatment modality of limited but unresectable hepatocellular carcinoma, liver metastasis, especially colorectal cancer metastases, primary lung tumors, renal cell carcinoma, boney metastasis and osteoid osteomas. The role of RFA in the primary treatment of early stage breast cancer is still evolving. This review will discuss the general features of RFA and outline its role in commonly encountered solid tumors. PMID:23671734

  15. Current applications of nanoparticles in infectious diseases.

    Science.gov (United States)

    Zazo, Hinojal; Colino, Clara I; Lanao, José M

    2016-02-28

    For decades infections have been treated easily with drugs. However, in the 21st century, they may become lethal again owing to the development of antimicrobial resistance. Pathogens can become resistant by means of different mechanisms, such as increasing the time they spend in the intracellular environment, where drugs are unable to reach therapeutic levels. Moreover, drugs are also subject to certain problems that decrease their efficacy. This requires the use of high doses, and frequent administrations must be implemented, causing adverse side effects or toxicity. The use of nanoparticle systems can help to overcome such problems and increase drug efficacy. Accordingly, there is considerable current interest in their use as antimicrobial agents against different pathogens like bacteria, virus, fungi or parasites, multidrug-resistant strains and biofilms; as targeting vectors towards specific tissues; as vaccines and as theranostic systems. This review begins with an overview of the different types and characteristics of nanoparticles used to deliver drugs to the target, followed by a review of current research and clinical trials addressing the use of nanoparticles within the field of infectious diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Application of laser produced plasmas for ion implantation techniques

    International Nuclear Information System (INIS)

    Hora, H.

    2005-01-01

    While all the classical ion sources, even the most advanced one like MEVVA of ECR sources, have space charge limited ion emission current densities of less than some mA per square centimeter, it is well known that laser driven ion sources are by many orders of magnitude different. After the well known phenomenon of very energetic highly charged fast ions, separated by their charge number Z, can all be explained now by the same mechanisms lead to 10.000 times higher ion current densities than in the classical case. For the opening of a systematic experimental clarification, we discuss the relevant theory. Another recent observation is analyzed why picosecond laser pulses result in the mentioned high ion energies only, if a prepulse is used. This has consequences to sub-picosecond laser-plasma interaction for the studies of the fast ignitor physics for laser fusion and for the new field of nuclear physics opened by these laser pulses producing up to 100 MeV particles and gammas of high density. (author)

  17. Note: Demonstration of an external-cavity diode laser system immune to current and temperature fluctuations.

    Science.gov (United States)

    Miao, Xinyu; Yin, Longfei; Zhuang, Wei; Luo, Bin; Dang, Anhong; Chen, Jingbiao; Guo, Hong

    2011-08-01

    We demonstrate an external-cavity laser system using an anti-reflection coated laser diode as gain medium with about 60 nm fluorescence spectrum, and a Rb Faraday anomalous dispersion optical filter (FADOF) as frequency-selecting element with a transmission bandwidth of 1.3 GHz. With 6.4% optical feedback, a single stable longitudinal mode is obtained with a linewidth of 69 kHz. The wavelength of this laser is operating within the center of the highest transmission peak of FADOF over a diode current range from 55 mA to 142 mA and a diode temperature range from 15 °C to 35 °C, thus it is immune to the fluctuations of current and temperature.

  18. Application of adaptive Kalman filter in vehicle laser Doppler velocimetry

    Science.gov (United States)

    Fan, Zhe; Sun, Qiao; Du, Lei; Bai, Jie; Liu, Jingyun

    2018-03-01

    Due to the variation of road conditions and motor characteristics of vehicle, great root-mean-square (rms) error and outliers would be caused. Application of Kalman filter in laser Doppler velocimetry(LDV) is important to improve the velocity measurement accuracy. In this paper, the state-space model is built by using current statistical model. A strategy containing two steps is adopted to make the filter adaptive and robust. First, the acceleration variance is adaptively adjusted by using the difference of predictive observation and measured observation. Second, the outliers would be identified and the measured noise variance would be adjusted according to the orthogonal property of innovation to reduce the impaction of outliers. The laboratory rotating table experiments show that adaptive Kalman filter greatly reduces the rms error from 0.59 cm/s to 0.22 cm/s and has eliminated all the outliers. Road experiments compared with a microwave radar show that the rms error of LDV is 0.0218 m/s, and it proves that the adaptive Kalman filtering is suitable for vehicle speed signal processing.

  19. Proceedings of the 4. International Conference on Lasers and their Applications

    International Nuclear Information System (INIS)

    400 scientists from 19 countries participated in the 4. international conference on lasers and their applications, held at Leipzig, GDR, in October 1981. The conference focused on problems of gas lasers, high-power lasers for materials working, and laser spectroscopy, on optoelectronics considering communications systems, and on laser-controlled thermonuclear fusion with special regard to the laser plant 'Delphin 1'. 186 summaries are included

  20. 50 years LASERS: in vitro diagnostics, clinical applications and perspectives.

    Science.gov (United States)

    Spyropoulos, Basile

    2011-01-01

    1960 Theodore Maiman built the first Ruby-LASER, starting-point for half a century of R&D on Biomedical LASER continuous improvement. The purpose of this paper is to contribute a review of the often disregarded, however, extremely important Industrial Property documents of LASER-based in vitro Diagnostics devices. It is an attempt to sketch-out the patent-trail leading towards the modern Biomedical Laboratory and to offer an introduction to the employment of "exotic" systems, such as the Free Electron LASER (FEL), that are expected to focus on the fundamental processes of life, following chemical reactions and biological processes as they happen, on unprecedented time and size scales. There are various in vitro LASER applications, however, the most important ones include: Hybrid Coulter Principle-LASER Hematology Analyzers. Flow Cytometry systems. Fluorescent in situ Hybridization (FISH Techniques). Confocal LASER Scanning Microscopy and Cytometry. From the first fluorescence-based flow Cytometry device developed in 1968 by Wolfgang Göhde until nowadays, numerous improvements and new features related to these devices appeared. The relevant industrial property milestone-documents and their overall numeral trends are presented. In 1971, J. Madey invented and developed the Free Electron LASER (FEL), a vacuum-tube that uses a beam of relativistic electrons passing through a periodic, transverse magnetic field (wiggler) to produce coherent radiation, contained in an optical cavity defined by mirrors. A resonance condition that involves the energy of the electron beam, the strength of the magnetic field, and the periodicity of the magnet determines the wavelength of the radiation. The FEL Coherent Light Sources like the Linac Coherent Light Source (LCLS) at Stanford, CA, USA or the Xray Free Electron LASER (XFEL) at Hamburg, Germany, will work much like a high-speed (LASERS. If the diodes brought a LASER into almost everyone's pocket, the above-mentioned super

  1. Efficient second harmonics generation of a laser-diode-pumped Nd:YAG laser and its applications. Laser diode reiki Nd:YAG laser no kokoritsu daini kochoha hassei to sono oyo

    Energy Technology Data Exchange (ETDEWEB)

    Kubota, S.; Oka, M. (Sony Corp., Tokyo (Japan))

    1991-08-10

    Stabilization of the second harmonics in a laser-diode-pumped Nd:YAG laser and its application are described. The laser is a quantum noise limiting laser, in which a mode competing noise is generated from an interaction between the laser medium Nd:YAG and the type II nonlinear optical crystal KTiOPO{sub 4} when generating a second harmonics in the resonator. However, the quantum noise limiting second harmonics was obtained by means of inserting (1/4) wave length plate in the resonator to release the bond between two intersecting inherent polarization modes. This stabilized green laser is of a single lateral mode is nearly free of aberration. Therefore, an optical disc prototype having three times as much of the currently used density was made using an objective lens having high number of openings to collect lights, which was verified capable of regeneration at a high signal to noise ratio. In addition, higher output is possible by means of parallelizing the excitation, and high output is realized from edge excitation at a fiber bundle. 18 refs., 3 figs.

  2. Laser application of heat pipe technology in energy related programs

    International Nuclear Information System (INIS)

    Carbone, R.J.

    1975-01-01

    The design and operating parameters for a heat pipe laser utilizing metal vapors are proposed. The laser would be applied to laser induced fusion, laser induced chemistry, laser isotope separation, and power transport using optical beams. (U.S.)

  3. Current limitation by an electric double layer in ion laser discharges

    International Nuclear Information System (INIS)

    Torven, S.

    1977-12-01

    A theory for current limitation in ion laser discharges is investigated. The basic mechanism considered is saturation of the positive ion flux at an electric double layer by the limited flux of neutral atoms. The result is compared with a recently published synthesis of a large number of experimental data which agree well with those predicted by the double layer model

  4. Improvement of light-current characteristic linearity in a quantum well laser with asymmetric barriers

    DEFF Research Database (Denmark)

    Zubov, F. I.; Zhukov, A. E.; Shernyakov, Yu M.

    2014-01-01

    The effect of asymmetric barriers on the light-current characteristic (LCC) of a quantum well laser was studied theoretically and experimentally. It is shown that the utilization of asymmetric barriers in a waveguide prevents the nonlinearity of LCC and, consequently, allows rising of the maximum...... output power....

  5. High energy, single frequency, tunable laser source operating in burst mode for space based lidar applications

    Science.gov (United States)

    Cosentino, Alberto; Mondello, Alessia; Sapia, Adalberto; D'Ottavi, Alessandro; Brotini, Mauro; Gironi, Gianna; Suetta, Enrico

    2017-11-01

    This paper describes energetic, spatial, temporal and spectral characterization measurements of the Engineering Qualification Model (EQM) of the Laser Transmitter Assembly (TXA) used in the ALADIN instrument currently under development for the ESA ADM-AEOLUS mission (EADS Astrium as prime contractor for the satellite and the instrument). The EQM is equivalent to the Flight Model, with the exception of some engineering grade components. The Laser Transmitter Assembly, based on a diode pumped tripled Nd:YAG laser, is used to generate laser pulses at a nominal wavelength of 355 nm. This laser is operated in burst mode, with a pulse repetition cycle of 100 Hz during bursts. It is capable to operate in Single Longitudinal Mode and to be tuned over 25 GHz range. An internal "network" of sensors has been implemented inside the laser architecture to allow "in flight" monitoring of transmitter. Energy in excess of 100 mJ, with a spatial beam quality factor (M2) lower than 3, a spectral linewidth less than 50 MHz with a frequency stability better than 4 MHz on short term period have been measured on the EQM. Most of the obtained results are well within the expected values and match the Instrument requirements. They constitute an important achievement, showing the absence of major critical areas in terms of performance and the capability to obtain them in a rugged and compact structure suitable for space applications. The EQM will be submitted in the near future to an Environmental test campaign.

  6. Application and generation of large amplitude plasma waves by beating of two intense laser beams

    International Nuclear Information System (INIS)

    Salomaa, R.R.E.; Karttunen, S.J.

    1986-01-01

    Large amplitude plasma waves which can be created by heating two intense laser beams are applicable e.g., to particle acceleration, to induction of plasma currents, and to plasma heating. A central issue in these applications is the nonlinear behaviour of the plasmon. We present a theory model where nonlinear frequency shifts in the plasmon evolution and formation of electromagnetic cascades by inelastic plasmon-photon scattering are accounted. The analytical temporal solution can be constructed in terms of Bessel functions and elliptic integrals. Implications of the results to the applications and further needs to refine the model are discussed. A suggestion for broadening the light spectrum in laserfusion is made. (orig.)

  7. Blue laser diode (LD) and light emitting diode (LED) applications

    International Nuclear Information System (INIS)

    Bergh, Arpad A.

    2004-01-01

    The family of blue LEDs, edge emitting and surface emitting lasers, enable a number of applications. Blue lasers are used in digital applications such as optical storage in high density DVDs. The resolution of the spot size and hence the storage density is diffraction limited and is inversely proportional to the square of the wavelength of the laser. Other applications include printing, optical scanners, and high-resolution photo-lithography. As light emitters, blue LEDs are used for signaling and in direct view large area emissive displays. They are also making inroads into signage and LCD back-lighting, mobile platforms, and decorative accent lighting in curtains, furniture, etc. Blue LEDs produce white light either with phosphor wavelength converters or in combination with red and green LEDs. The full potential of LED light sources will require three devices to enable complete control over color and intensity. Sensing and medical/bio applications have a major impact on home security, on monitoring the environment, and on health care. New emerging diagnostic and therapeutic applications will improve the quality and reduce the cost of health care. (copyright 2004 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim) (orig.)

  8. Novel applications of femtosecond laser in missile countermeasures

    Science.gov (United States)

    Marquis, E.; Pocholle, J. P.

    2005-11-01

    Femtosecond lasers have been widely used in laboratories for years and are now suitable for industrial applications and new military ones. Due to their very short pulse duration, they have the capability to generate intense electric fields and plasmas in targeted materials. We present here a novel scheme of missile counter-measure that is using such an intense laser source to disrupt the operation of IR guidance systems. Classical lasers for missile defense are based on thermal effects on the target whereas photons are used as the kill vehicle [1,2]. In femtosecond countermeasure, the average power is quite low, but the very intense field creates ionization effects than can damage sensitive optics and also plasma that can be used as active decoys against IR homing electronics. As the recent systems are compact and portable, an airport protection scheme is proposed to eliminate manpads threats in the vicinity of a civilian airport.

  9. Portable laser-heating stand for synchrotron applications

    Science.gov (United States)

    Boehler, R.; Musshoff, H. G.; Ditz, R.; Aquilanti, G.; Trapananti, A.

    2009-04-01

    A compact, double-sided laser-heating system for diamond-cell synchrotron applications is described. The optical table, containing laser, spectrometer, and all optics for visual observation and measuring temperatures and pressures has an area of less than 1/2 m2 and weighs less than 20 kg. All components can be remotely controlled at micron levels with simple dc motors and pneumatic drives. The design allows quick alignment of the laser-heated hot spot with the x-ray beam and the spectrometer. The prealigned system can be set up at most synchrotron beamlines within about 1 h. We carried out measurements on a variety of materials above one megabar and up to over 4000 K at both the x-ray diffraction beamline ID 27 and the x-ray absorption beamline ID 24 at the European Synchrotron Facility. A new measurement of the melting temperature of iron by x-ray absorption spectroscopy is presented.

  10. Characterization of nanoparticle mediated laser transfection by femtosecond laser pulses for applications in molecular medicine.

    Science.gov (United States)

    Schomaker, Markus; Heinemann, Dag; Kalies, Stefan; Willenbrock, Saskia; Wagner, Siegfried; Nolte, Ingo; Ripken, Tammo; Murua Escobar, Hugo; Meyer, Heiko; Heisterkamp, Alexander

    2015-02-03

    In molecular medicine, the manipulation of cells is prerequisite to evaluate genes as therapeutic targets or to transfect cells to develop cell therapeutic strategies. To achieve these purposes it is essential that given transfection techniques are capable of handling high cell numbers in reasonable time spans. To fulfill this demand, an alternative nanoparticle mediated laser transfection method is presented herein. The fs-laser excitation of cell-adhered gold nanoparticles evokes localized membrane permeabilization and enables an inflow of extracellular molecules into cells. The parameters for an efficient and gentle cell manipulation are evaluated in detail. Efficiencies of 90% with a cell viability of 93% were achieved for siRNA transfection. The proof for a molecular medical approach is demonstrated by highly efficient knock down of the oncogene HMGA2 in a rapidly proliferating prostate carcinoma in vitro model using siRNA. Additionally, investigations concerning the initial perforation mechanism are conducted. Next to theoretical simulations, the laser induced effects are experimentally investigated by spectrometric and microscopic analysis. The results indicate that near field effects are the initial mechanism of membrane permeabilization. This methodical approach combined with an automated setup, allows a high throughput targeting of several 100,000 cells within seconds, providing an excellent tool for in vitro applications in molecular medicine. NIR fs lasers are characterized by specific advantages when compared to lasers employing longer (ps/ns) pulses in the visible regime. The NIR fs pulses generate low thermal impact while allowing high penetration depths into tissue. Therefore fs lasers could be used for prospective in vivo applications.

  11. Excimer laser with high pulse energy and typical applications

    International Nuclear Information System (INIS)

    Jetter, H.L.; Schmatjko, K.J.; Schroeder, M.

    1989-01-01

    This paper reports on a research program for scaling excimer lasers of high pulse energy (>2J) in output power. A XeCl laser operated with paralleled waterline capacitors and a hollow cathode type x-ray gun has yielded 225 W at a pulse energy of >2,25 J and a repetition rate of 100 Hz. A short laser of 15 cm gain length was designed as a flexible tool for quick modification of components and for having more reserve in electrical power and gas throughput for scaling. So far with the short gain length and XeCl 0,56 J pulse energy were achieved. Applications of high pulse energy lasers focus on material processing. A Siemens XP 2020 excimer laser was used for structured removal of different coating/substrate systems of metals, ceramics and polymers, e.g. metal coating on ceramics, ceramic protection on steel, superconducting ceramic films on ceramics, polyimide on copper and metals sputtered on copper

  12. Types of Lasers and Their Applications in Pediatric Dentistry.

    Science.gov (United States)

    Nazemisalman, Bahareh; Farsadeghi, Mahya; Sokhansanj, Mehdi

    2015-01-01

    Laser technology has been recently introduced into the dental field with the idea to replace drilling. Having a less painful first dental experience by the use of modern instruments like laser can be an efficient preventive and therapeutic strategy in pediatric dentistry. Pedodontists need to learn the new less invasive technologies and adopt them in their routine practice. This study aimed to review the available types of lasers and their applications in pediatric dentistry. An electronic search was carried out in IranMedex, InterScience, Scopus, Science Direct, PubMed, ProQuest, Medline and Google Scholar databases to find relevant articles published from 2000 to 2014. Relevant textbooks were reviewed as well. Laser can be used as a suitable alternative to many conventional diagnostic and therapeutic dental procedures. It is especially efficient for caries detection and removal, pulp therapy, lowering the risk of infection, inflammation and swelling and reducing bleeding. On the other hand, due to minimal invasion, laser treatment is well tolerated by children. Improved patient cooperation leads to higher satisfaction of the parents, dentists and the children themselves.

  13. The free-electron laser - Maxwell's equations driven by single-particle currents

    Science.gov (United States)

    Colson, W. B.; Ride, S. K.

    1980-01-01

    It is shown that if single particle currents are coupled to Maxwell's equations, the resulting set of self-consistent nonlinear equations describes the evolution of the electron beam and the amplitude and phase of the free-electron-laser field. The formulation is based on the slowly varying amplitude and phase approximation, and the distinction between microscopic and macroscopic scales, which distinguishes the microscopic bunching from the macroscopic pulse propagation. The capabilities of this new theoretical approach become apparent when its predictions for the ultrashort pulse free-electron laser are compared to experimental data; the optical pulse evolution, determined simply and accurately, agrees well with observations.

  14. Attoclock reveals natural coordinates of the laser-induced tunnelling current flow in atoms

    DEFF Research Database (Denmark)

    Pfeiffer, Adrian N.; Cirelli, Claudio; Smolarski, Mathias

    2012-01-01

    In the research area of strong-laser-field interactions and attosecond science1, tunnelling of an electron through the barrier formed by the electric field of the laser and the atomic potential is typically assumed to be the initial key process that triggers subsequent dynamics1, 2, 3. Here we use...... the attoclock technique4 to obtain experimental information about the electron tunnelling geometry (the natural coordinates of the tunnelling current flow) and exit point. We confirm vanishing tunnelling delay time, show the importance of the inclusion of Stark shifts5, 6 and report on multi-electron effects...

  15. High current, high energy proton beams accelerated by a sub-nanosecond laser

    Czech Academy of Sciences Publication Activity Database

    Margarone, Daniele; Krása, Josef; Picciotto, A.; Torrisi, L.; Láska, Leoš; Velyhan, Andriy; Prokůpek, Jan; Ryc, L.; Parys, P.; Ullschmied, Jiří; Rus, Bedřich

    2011-01-01

    Roč. 653, č. 1 (2011), s. 159-163 ISSN 0168-9002 R&D Projects: GA ČR(CZ) GAP205/11/1165; GA AV ČR IAA100100715; GA MŠk(CZ) 7E09092 EU Projects: European Commission(XE) 212105 - ELI-PP Institutional research plan: CEZ:AV0Z10100523; CEZ:AV0Z20430508 Keywords : laser-acceleration * proton beam * high ion current * time -of-flight * proton energy distribution Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.207, year: 2011

  16. Geometric validation of a mobile laser scanning system for urban applications

    Science.gov (United States)

    Guan, Haiyan; Li, Jonathan; Yu, Yongtao; Liu, Yan

    2016-03-01

    Mobile laser scanning (MLS) technologies have been actively studied and implemented over the past decade, as their application fields are rapidly expanding and extending beyond conventional topographic mapping. Trimble's MX-8, as one of the MLS systems in the current market, generates rich survey-grade laser and image data for urban surveying. The objective of this study is to evaluate whether Trimble MX-8 MLS data satisfies the accuracy requirements of urban surveying. According to the formula of geo-referencing, accuracies of navigation solution and laser scanner determines the accuracy of the collected LiDAR point clouds. Two test sites were selected to test the performance of Trimble MX-8. Those extensive tests confirm that Trimble MX-8 offers a very promising tool to survey complex urban areas.

  17. Fundamental transverse mode selection and self-stabilization in large optical cavity diode lasers under high injection current densities

    Science.gov (United States)

    Avrutin, Eugene A.; Ryvkin, Boris S.; Payusov, Alexey S.; Serin, Artem A.; Gordeev, Nikita Yu

    2015-11-01

    It is shown that in high-power, large optical cavity laser diodes at high injection currents, the optical losses due to nonuniform carrier accumulation in the optical confinement layer can ensure the laser operation in the fundamental transverse mode. An experimental demonstration of switching from second order mode to fundamental mode in large optical cavity lasers with current and/or temperature increase is reported and explained, with the calculated values for the switching current and temperature in good agreement with the measurements. The results experimentally prove the nonuniform nature of carrier accumulation in the confinement layer and may aid laser design for optimizing the output.

  18. Defence and security applications of quantum cascade lasers

    Science.gov (United States)

    Grasso, Robert J.

    2016-09-01

    Quantum Cascade Lasers (QCL) have seen tremendous recent application in the realm of Defence and Security. And, in many instances replacing traditional solid state lasers as the source of choice for Countermeasures, Remote Sensing, In-situ Sensing, Through-Barrier Sensing, and many others. Following their development and demonstration in the early 1990's, QCL's reached some maturity and specific defence and security application prior to 2005; with much initial development fostered by DARPA initiatives in the US, dstl, MoD, and EOARD funding initiatives in the UK, and University level R&D such as those by Prof Manijeh Razeghi at Northwestern University [1], and Prof Ted Masselink at Humboldt University [2]. As QCL's provide direct mid-IR laser output for electrical input, they demonstrate high quantum efficiency compared with diode pumped solid state lasers with optical parametric oscillators (OPOs) to generate mid-Infrared output. One particular advantage of QCL's is their very broad operational bandwidth, extending from the terahertz to the near-infrared spectral regions. Defence and Security areas benefiting from QCL's include: Countermeasures, Remote Sensing, Through-the-Wall Sensing, and Explosive Detection. All information used to construct this paper obtained from open sources.

  19. Diode-pumped all-solid-state lasers and applications

    CERN Document Server

    Parsons-Karavassilis, D

    2002-01-01

    This thesis describes research carried out by the within the Physics Department at Imperial College that was aimed at developing novel all-solid-state laser sources and investigating potential applications of this technology. A description of the development, characterisation and application of a microjoule energy level, diode-pumped all-solid-state Cr:LiSGAF femtosecond oscillator and regenerative amplifier system is presented. The femtosecond oscillator was pumped by two commercially available laser diodes and produced an approx 80 MHz pulse train of variable pulse duration with approx 30 mW average output power and a tuning range of over approx 60 nm. This laser oscillator was used to seed a regenerative amplifier, resulting in adjustable repetition rate (single pulse to 20 kHz) approx 1 mu J picosecond pulses. These pulses were compressed to approx 150 fs using a double-pass twin-grating compressor. The amplifier's performance was investigated with respect to two different laser crystals and different pul...

  20. Trapping and manipulation of microparticles using laser-induced convection currents and photophoresis.

    Science.gov (United States)

    Flores-Flores, E; Torres-Hurtado, S A; Páez, R; Ruiz, U; Beltrán-Pérez, G; Neale, S L; Ramirez-San-Juan, J C; Ramos-García, R

    2015-10-01

    In this work we demonstrate optical trapping and manipulation of microparticles suspended in water due to laser-induced convection currents. Convection currents are generated due to laser light absorption in an hydrogenated amorphous silicon (a:Si-H) thin film. The particles are dragged towards the beam's center by the convection currents (Stokes drag force) allowing trapping with powers as low as 0.8 mW. However, for powers >3 mW trapped particles form a ring around the beam due to two competing forces: Stokes drag and thermo-photophoretic forces. Additionally, we show that dynamic beam shaping can be used to trap and manipulate multiple particles by photophotophoresis without the need of lithographically created resistive heaters.

  1. Trapping and manipulation of microparticles using laser-induced convection currents and photophoresis

    Science.gov (United States)

    Flores-Flores, E.; Torres-Hurtado, S. A.; Páez, R.; Ruiz, U.; Beltrán-Pérez, G.; Neale, S. L.; Ramirez-San-Juan, J. C.; Ramos-García, R.

    2015-01-01

    In this work we demonstrate optical trapping and manipulation of microparticles suspended in water due to laser-induced convection currents. Convection currents are generated due to laser light absorption in an hydrogenated amorphous silicon (a:Si-H) thin film. The particles are dragged towards the beam's center by the convection currents (Stokes drag force) allowing trapping with powers as low as 0.8 mW. However, for powers >3 mW trapped particles form a ring around the beam due to two competing forces: Stokes drag and thermo-photophoretic forces. Additionally, we show that dynamic beam shaping can be used to trap and manipulate multiple particles by photophotophoresis without the need of lithographically created resistive heaters. PMID:26504655

  2. Photoinduced electric currents in ring-shaped molecules by circularly polarized laser pulses

    International Nuclear Information System (INIS)

    Nobusada, Katsuyuki; Yabana, Kazuhiro

    2007-01-01

    We have theoretically demonstrated that circularly polarized laser pulses induce electric currents and magnetic moments in ring-shaped molecules Na 10 and benzene. The time-dependent adiabatic local density approximation is employed for this purpose, solving the time-dependent Kohn-Sham equation in real space and real time. It has been found that the electric currents are induced efficiently and persist continuously even after the laser pulses were switched off provided the frequency of the applied laser pulse is in tune with the excitation energy of the electronic excited state with the dipole strength for each molecular system. The electric currents are definitely revealed to be a second-order nonlinear optical response to the magnitude of the electric field. The magnetic dipole moments inevitably accompany the ring currents, so that the molecules are magnetized. The production of the electric currents and the magnetic moments in the present procedure is found to be much more efficient than that utilizing static magnetic fields

  3. Development of high current electron source using photoemission from metals with ultrashort laser pulses

    International Nuclear Information System (INIS)

    Tsang, T.; Srinivasan-Rao, T.; Fischer, J.

    1990-10-01

    We summarize the studies of photoemission from metal photocathodes using picosecond pulses in the UV (4.66 eV) wavelength and femtosecond laser pulses in the visible (2 eV) wavelengths. To achieve high current density yield from metal photocathodes, multiphoton photoemission using femtosecond laser pulses are suggested. Electron yield improvement incorporating surface photoemission and surface plasmon resonance in metals and metal films are demonstrated. We examine the possibility of the nonlinear photoemission process overtaking the linear process, and identity some possible complexity. To extract the large amount of electrons free of space charge, a pulsed high voltage is designed; the results of the preliminary test are presented. Finally, for the first time, the width of the electron temporal profiles are measured, utilizing the nonlinear photoelectric effect, to below 100 fsec time regime. The results indicated that the electron pulse duration follows the laser pulses and are not limited by the material. 8 refs., 15 figs

  4. Comparison of transcatheter laser and direct-current shock ablation of endocardium near tricuspid anulus

    Science.gov (United States)

    Zhang, Yu-Zhen; Wang, Shi-Wen; Li, Junheng

    1993-03-01

    Forty to eighty percent of the patients with accessory pathways (APs) manifest themselves by tachyarrhythmias. Many of these patients needed either life-long medical therapy or surgery. In order to avoid the discomfort and expenses in surgical procedures, closed chest percutaneous catheter ablation of APs became a potentially desirable therapeutic approach. Many investigations indicated that ablation of right APs by transcatheter direct current (dc) shock could cause life-threatening arrhythmias, right coronary arterical (RCA) spasm, etc. With the development of transcatheter laser technique, it has been used in drug-incurable arrhythmias. The results show that laser ablation is much safer than surgery and electric shock therapy. The purpose of this study is to explore the effectiveness, advantages, and complications with transcatheter Nd:YAG laser and dc shock in the ablation of right atrioventricular accessory pathways in the atrium near the tricuspid annulus (TA) in 20 dogs.

  5. Laser assisted die bending: a new application of high power diode lasers

    Science.gov (United States)

    Schuöcker, D.; Schumi, T.; Spitzer, O.; Bammer, F.; Schuöcker, G.; Sperrer, G.

    2015-02-01

    Nowadays high power lasers are mainly used for cutting of sheet metals, for welding, hardening and rapid prototyping. In the forming of sheet metals as bending or deep drawing lasers are not used. Nevertheless a few years ago a new application of high power lasers has been invented, where bending of materials that break at room temperature becomes possible by heating them along the bending edge with high power lasers thus allowing their treatment without cracks and rupture. For this purpose a large number of diode lasers are arranged in the bottom tool of a bending machine (a V-shaped die) which heat up the initially flat sheet metal during the bending process what is performed by pressing it into the die with a knife shaped upper tool where due to the laser heating the material is softened and thus cracks are avoided. For the technical realization of the new process of laser assisted die bending, modules equipped with numerous laser diodes and a total beam power of 2,5 kW are used. The light emitted by these modules enters a tool with a length of 15cm and is deflected towards the workpiece. By using ten of these modules with adjacent dies and by integrating those in a bending press a bending edge of sheet metals with a length of 1500mm can be realized. Such a bending press with laser assistance also needs energization with a power of practically 50kW, a respective water flow, a heat exchanger system and also a control for all functions of this system. Special measures have also been developed to avoid radiating of those tools that are not covered by a workpiece in the case of bending edges shorter than the full length of the bending tools whereas individual short circuiting of diode modules can be performed. Specific measures to ensure a safe operation without any harm to the operational person have been realized. Exploitation of the bending process has been carried out for titanium, where material thicknesses up to 3mm have been bent successfully.

  6. Recent advances in phosphate laser glasses for high power applications

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, J.H.

    1996-05-14

    Recent advances in Nd-doped phosphate laser glasses for high-peak-power and high-average-power applications are reviewed. Compositional studies have progressed to the point that glasses can be tailored to have specific properties for specific applications. Non-radiative relaxation effects can be accurately modeled and empirical expressions have been developed to evaluate both intrinsic (structural) and extrinsic (contamination induced) relaxation effects. Losses due to surface scattering and bulk glass absorption have been carefully measured and can be accurately predicted. Improvements in processing have lead to high damage threshold (e.g. Pt inclusion free) and high thermal shock resistant glasses with improved edge claddings. High optical quality pieces up to 79 x 45 x 4cm{sup 3} have been made and methods for continuous melting laser glass are under development.

  7. Recent advances in phosphate laser glasses for high power applications

    International Nuclear Information System (INIS)

    Campbell, J.H.

    1996-01-01

    Recent advances in Nd-doped phosphate laser glasses for high-peak-power and high-average-power applications are reviewed. Compositional studies have progressed to the point that glasses can be tailored to have specific properties for specific applications. Non-radiative relaxation effects can be accurately modeled and empirical expressions have been developed to evaluate both intrinsic (structural) and extrinsic (contamination induced) relaxation effects. Losses due to surface scattering and bulk glass absorption have been carefully measured and can be accurately predicted. Improvements in processing have lead to high damage threshold (e.g. Pt inclusion free) and high thermal shock resistant glasses with improved edge claddings. High optical quality pieces up to 79 x 45 x 4cm 3 have been made and methods for continuous melting laser glass are under development

  8. Applications of laser-induced gratings to spectroscopy and dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Rohlfing, E.A. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    This program has traditionally emphasized two principal areas of research. The first is the spectroscopic characterization of large-amplitude motion on the ground-state potential surface of small, transient molecules. The second is the reactivity of carbonaceous clusters and its relevance to soot and fullerene formation in combustion. Motivated initially by the desire to find improved methods of obtaining stimulated emission pumping (SEP) spectra of transients, most of our recent work has centered on the use of laser-induced gratings or resonant four-wave mixing in free-jet expansions. These techniques show great promise for several chemical applications, including molecular spectroscopy and photodissociation dynamics. The author describes recent applications of two-color laser-induced grating spectroscopy (LIGS) to obtain background-free SEP spectra of transients and double resonance spectra of nonfluorescing species, and the use of photofragment transient gratings to probe photodissociation dynamics.

  9. Applications of Light Amplification by Stimulated Emission of Radiation (Lasers) for Restorative Dentistry

    Science.gov (United States)

    Najeeb, Shariq; Khurshid, Zohaib; Zafar, Muhammad Sohail; Ajlal, Syed

    2016-01-01

    Light amplification by stimulated emission of radiation (laser) has been used widely in a range of biomedical and dental applications in recent years. In the field of restorative dentistry, various kinds of lasers have been developed for diagnostic (e.g. caries detection) and operative applications (e.g. tooth ablation, cavity preparation, restorations, bleaching). The main benefits for laser applications are patient comfort, pain relief and better results for specific applications. Major concerns for using dental lasers frequently are high cost, need for specialized training and sensitivity of the technique, thereby compromising its usefulness particularly in developing countries. The main aim of this paper is to evaluate and summarize the applications of lasers in restorative dentistry, including a comparison of the applications of lasers for major restorative dental procedures and conventional clinical approaches. A remarkable increase in the use of lasers for dental application is expected in the near future. PMID:26642047

  10. Atomic Physics at Accelerators: Laser Spectroscopy and Applications

    Science.gov (United States)

    Letokhov, Vladilen

    From 19 to 24 September, 1999, the First European Conference Atomic Physics at Accelerators: Laser Spectroscopy and Applications (APAC'99) was held at University of Mainz and Schloss Waldhausen (Budenheim, Germany) under the chairmanship of H. Backe and G. Huber. The idea of this up-to-date conference was associated with the 65th anniversary of Professor Ernst Otten (University of Mainz) who, together with H. Kluge, contributed much to the development of this work at CERN, University of Mainz, and Darmstadt.

  11. Ultra-stable clock laser system development towards space applications.

    Science.gov (United States)

    Świerad, Dariusz; Häfner, Sebastian; Vogt, Stefan; Venon, Bertrand; Holleville, David; Bize, Sébastien; Kulosa, André; Bode, Sebastian; Singh, Yeshpal; Bongs, Kai; Rasel, Ernst Maria; Lodewyck, Jérôme; Le Targat, Rodolphe; Lisdat, Christian; Sterr, Uwe

    2016-09-26

    The increasing performance of optical lattice clocks has made them attractive for scientific applications in space and thus has pushed the development of their components including the interrogation lasers of the clock transitions towards being suitable for space, which amongst others requires making them more power efficient, radiation hardened, smaller, lighter as well as more mechanically stable. Here we present the development towards a space-compatible interrogation laser system for a strontium lattice clock constructed within the Space Optical Clock (SOC2) project where we have concentrated on mechanical rigidity and size. The laser reaches a fractional frequency instability of 7.9 × 10 -16 at 300 ms averaging time. The laser system uses a single extended cavity diode laser that gives enough power for interrogating the atoms, frequency comparison by a frequency comb and diagnostics. It includes fibre link stabilisation to the atomic package and to the comb. The optics module containing the laser has dimensions 60 × 45 × 8 cm 3 ; and the ultra-stable reference cavity used for frequency stabilisation with its vacuum system takes 30 × 30 × 30 cm 3 . The acceleration sensitivities in three orthogonal directions of the cavity are 3.6 × 10 -10 /g, 5.8 × 10 -10 /g and 3.1 × 10 -10 /g, where g ≈ 9.8 m/s 2 is the standard gravitational acceleration.

  12. Proposal of a defense application for a chemical oxygen laser

    Science.gov (United States)

    Takehisa, K.

    2015-05-01

    Defense application for a chemical oxygen laser (COL) is explained. Although a COL has not yet been successful in lasing, the oscillator was estimated to produce a giant pulse with the full width at half maximum (FWHM) of ~0.05ms which makes the damage threshold for the mirrors several-order higher than that for a typical solid-state laser with a ~10ns pulse width. Therefore it has a potential to produce MJ class output considering the simple scalability of being a chemical laser. Since within 0.05ms a supersonic aircraft can move only a few centimeters which is roughly equal to the spot size of the focused beam at ~10km away using a large-diameter focusing mirror, a COL has a potential to make a damage to an enemy aircraft by a single shot without beam tracking. But since the extracted beam can propagate up to a few kilometers due to the absorption in the air, it may be suitable to use in space. While a chemical oxygen-iodine laser (COIL) can give a pulsed output with a width of ~2 ms using a high-pressure singlet oxygen generator (SOG). Therefore a pulsed COIL may also not require beam tracking if a target aircraft is approaching. Another advantage for these pulsed high-energy lasers (HELs) is that, in case of propagating in cloud or fog, much less energy is required for a laser for aerosol vaporization (LAV) than that of a LAV for a CW HEL. Considerations to use a COL as a directed energy weapon (DEW) in a point defense system are shown.

  13. Lasers in medical applications: R and D mapping

    International Nuclear Information System (INIS)

    Deokattey, Sangeeta; Kalyane, V.L.; Kumar, Vijai; Phool Chand

    2001-10-01

    A study of the MEDLINE CDROM database, for the period 1969-2000 was undertaken. The purpose was, to identify core areas of research and development, in the field of applications of lasers to humans, along with other bibliometric indicators of research. A total of 34,833 records were retrieved, downloaded and analysed. The results indicate a steady increase in the number of publications every year, from 1970 onwards, with 1997 (2767 articles) and 1998 (2914 articles) being the most productive years. The most prolific contributors were J. Haut, with 95 publications to his credit, followed by M. Landthaler (82), G. Coscas (79), S.G. Bown (73) and P. Bjerring (70). Collaboration among the authors was high, with a maximum of 15 contributors observed in a few articles. The top ranking journal in the field was Ophthalmology, which published 769 articles starting from 1978. USA was way ahead as the country with the highest journal productivity (around 40% of the total number of records), followed by UK and Germany. A total of 103 articles were published from India. English was the preferred language of publication, with 75% of the records being published in English language. In the use of lasers for humans, maximum number of records were found for adult and middle aged populations. Research focussed on the eye and its various diseases. Lasers were found to be used for therapeutic purposes, in surgery and in the diagnosis of diseases. Carbon dioxide laser was most frequently used for medical applications. Though there were quite a few references on the adverse effects of lasers, the therapeutic effects far outweighed them. (author)

  14. Laser Isotope Enrichment for Medical and Industrial Applications

    International Nuclear Information System (INIS)

    Leonard Bond

    2006-01-01

    Laser Isotope Enrichment for Medical and Industrial Applications by Jeff Eerkens (University of Missouri), Jay Kunze (Idaho State University), and Leonard Bond (Idaho National Laboratory) The principal isotope enrichment business in the world is the enrichment of uranium for commercial power reactor fuels. However, there are a number of other needs for separated isotopes. Some examples are: (1) Pure isotopic targets for irradiation to produce medical radioisotopes. (2) Pure isotopes for semiconductors. (3) Low neutron capture isotopes for various uses in nuclear reactors. (4) Isotopes for industrial tracer/identification applications. Examples of interest to medicine are targets to produce radio-isotopes such as S-33, Mo-98, Mo-100, W-186, Sn-112; while for MRI diagnostics, the non-radioactive Xe-129 isotope is wanted. For super-semiconductor applications some desired industrial isotopes are Si-28, Ga-69, Ge-74, Se-80, Te-128, etc. An example of a low cross section isotope for use in reactors is Zn-68 as a corrosion inhibitor material in nuclear reactor primary systems. Neutron activation of Ar isotopes is of interest in industrial tracer and diagnostic applications (e.g. oil-logging). . In the past few years there has been a sufficient supply of isotopes in common demand, because of huge Russian stockpiles produced with old electromagnetic and centrifuge separators previously used for uranium enrichment. Production of specialized isotopes in the USA has been largely accomplished using old ''calutrons'' (electromagnetic separators) at Oak Ridge National Laboratory. These methods of separating isotopes are rather energy inefficient. Use of lasers for isotope separation has been considered for many decades. None of the proposed methods have attained sufficient proof of principal status to be economically attractive to pursue commercially. Some of the authors have succeeded in separating sulfur isotopes using a rather new and different method, known as condensation

  15. Laser Isotope Enrichment for Medical and Industrial Applications

    Energy Technology Data Exchange (ETDEWEB)

    Leonard Bond

    2006-07-01

    Laser Isotope Enrichment for Medical and Industrial Applications by Jeff Eerkens (University of Missouri), Jay Kunze (Idaho State University), and Leonard Bond (Idaho National Laboratory) The principal isotope enrichment business in the world is the enrichment of uranium for commercial power reactor fuels. However, there are a number of other needs for separated isotopes. Some examples are: 1) Pure isotopic targets for irradiation to produce medical radioisotopes. 2) Pure isotopes for semiconductors. 3) Low neutron capture isotopes for various uses in nuclear reactors. 4) Isotopes for industrial tracer/identification applications. Examples of interest to medicine are targets to produce radio-isotopes such as S-33, Mo-98, Mo-100, W-186, Sn-112; while for MRI diagnostics, the non-radioactive Xe-129 isotope is wanted. For super-semiconductor applications some desired industrial isotopes are Si-28, Ga-69, Ge-74, Se-80, Te-128, etc. An example of a low cross section isotope for use in reactors is Zn-68 as a corrosion inhibitor material in nuclear reactor primary systems. Neutron activation of Ar isotopes is of interest in industrial tracer and diagnostic applications (e.g. oil-logging). . In the past few years there has been a sufficient supply of isotopes in common demand, because of huge Russian stockpiles produced with old electromagnetic and centrifuge separators previously used for uranium enrichment. Production of specialized isotopes in the USA has been largely accomplished using old ”calutrons” (electromagnetic separators) at Oak Ridge National Laboratory. These methods of separating isotopes are rather energy inefficient. Use of lasers for isotope separation has been considered for many decades. None of the proposed methods have attained sufficient proof of principal status to be economically attractive to pursue commercially. Some of the authors have succeeded in separating sulfur isotopes using a rather new and different method, known as condensation

  16. Laser-generated air contaminants from medical laser applications: a state-of-the-science review of exposure characterization, health effects, and control.

    Science.gov (United States)

    Pierce, Jennifer S; Lacey, Steven E; Lippert, Julia F; Lopez, Ramon; Franke, John E

    2011-07-01

    The clinical use of lasers in surgery began in 1973 with applications of the carbon dioxide laser in otolaryngology, and since then the use of lasers has become commonplace in many medical and surgical specialties. Nonetheless, when biological tissue is subjected to laser radiation, the target cells can be vaporized, resulting in the aerosolization of their contents and the subsequent exposure of health care workers to laser-generated air contaminants (LGACs). The purpose of our analysis was to summarize and present all of the published literature pertaining to the laser-induced plume chemical and physical composition, health effects, and methods of control. The objective was to identify knowledge gaps within exposure science to set a research agenda for the protection of health care personnel exposed to LGACs. A literature search was performed using the PubMed database using a variety of search strategies and keyword combinations. To locate additional studies, we systematically searched the reference lists of all studies identified by our search, as well as key review papers. To date, researchers have identified roughly 150 chemical constituents of plume, as well as fine and ultrafine particulate matter, which has been shown to include viable cellular material, viruses, and bacteria. However, very few studies have attempted to characterize the effects of laser system type, power, and tissue treated, as it relates to LGAC exposure. Furthermore, current control strategies do not appear to be adequate in preventing occupational exposure to LGACs.

  17. Experimental Investigation on Electric Current-Aided Laser Stake Welding of Aluminum Alloy T-Joints

    Directory of Open Access Journals (Sweden)

    Xinge Zhang

    2017-11-01

    Full Text Available In the present study, aluminum alloy T-joints were welded using the laser stake-welding process. In order to improve the welding quality of the T-joints, an external electric current was used to aid the laser stake-welding process. The effects of the process parameters on the weld morphology, mechanical properties, and microstructure of the welded joints were analyzed and discussed in detail. The results indicate that the aided electric current should be no greater than a certain maximum value. Upon increasing the aided electric current, the weld width at the skin and stringer faying surface obviously increased, but there was an insignificant change in the penetration depth. Furthermore, the electric current and pressing force should be chosen to produce an expected weld width at the faying surface, whereas the laser power and welding speed should be primarily considered to obtain an optimal penetration depth. The tensile shear specimens failed across the faying surface or failed in the weld zone of the skin. The specimens that failed in the weld of the skin could resist a higher tensile shear load compared with specimens that failed across the faying surface. The microstructural observations and microhardness results demonstrated that the tensile shear load capacity of the aluminum alloy welded T-joint was mainly determined by the weld width at the faying surface.

  18. LASER PLASMA AND LASER APPLICATIONS: Plasma transparency in laser absorption waves in metal capillaries

    Science.gov (United States)

    Anisimov, V. N.; Kozolupenko, A. P.; Sebrant, A. Yu

    1988-12-01

    An experimental investigation was made of the plasma transparency to heating radiation in capillaries when absorption waves propagated in these capillaries as a result of interaction with a CO2 laser pulse of 5-μs duration. When the length of the capillary was in excess of 20 mm, total absorption of the radiation by the plasma was observed at air pressures of 1-100 kPa. When the capillary length was 12 mm, a partial recovery of the transparency took place. A comparison was made with the dynamics and recovery of the plasma transparency when breakdown of air took place near the free surface.

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

    International Nuclear Information System (INIS)

    Golyaev, Yu D; Kolbas, Yu Yu

    2012-01-01

    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)

  20. Strengthened glass for high average power laser applications

    International Nuclear Information System (INIS)

    Cerqua, K.A.; Lindquist, A.; Jacobs, S.D.; Lambropoulos, J.

    1987-01-01

    Recent advancements in high repetition rate and high average power laser systems have put increasing demands on the development of improved solid state laser materials with high thermal loading capabilities. The authors have developed a process for strengthening a commercially available Nd doped phosphate glass utilizing an ion-exchange process. Results of thermal loading fracture tests on moderate size (160 x 15 x 8 mm) glass slabs have shown a 6-fold improvement in power loading capabilities for strengthened samples over unstrengthened slabs. Fractographic analysis of post-fracture samples has given insight into the mechanism of fracture in both unstrengthened and strengthened samples. Additional stress analysis calculations have supported these findings. In addition to processing the glass' surface during strengthening in a manner which preserves its post-treatment optical quality, the authors have developed an in-house optical fabrication technique utilizing acid polishing to minimize subsurface damage in samples prior to exchange treatment. Finally, extension of the strengthening process to alternate geometries of laser glass has produced encouraging results, which may expand the potential or strengthened glass in laser systems, making it an exciting prospect for many applications

  1. LIGHT - from laser ion acceleration to future applications

    Science.gov (United States)

    Roth, Markus; Light Collaboration

    2013-10-01

    Creation of high intensity multi-MeV ion bunches by high power lasers became a reliable tool during the last 15 years. The laser plasma source provides for TV/m accelerating field gradients and initially sub-ps bunch lengths. However, the large envelope divergence and the continuous exponential energy spectrum are substential drawbacks for many possible applications. To face this problem, the LIGHT collaboration was founded (Laser Ion Generation, Handling and Transport). The collaboration consists of several university groups and research centers, namely TU Darmstadt, JWGU Frankfurt, HI Jena, HZDR Dresden and GSI Darmstadt. The central goal is building a test beamline for merging laser ion acceleration with conventional accelerator infrastructure at the GSI facility. In the latest experiments, low divergent proton bunches with a central energy of up to 10 MeV and containing >109 particles could be provided at up to 2.2 m behind the plasma source, using a pulsed solenoid. In a next step, a radiofrequency cavity will be added to the beamline for phase rotation of these bunches, giving access to sub-ns bunch lengths and reaching highest intensities. An overview of the LIGHT objectives and the recent experimental results will be given. This work was supported by HIC4FAIR.

  2. Evaluation of a laser alignment system for IORT satellite applicators

    International Nuclear Information System (INIS)

    Boyer, A.L.; Hogstrom, R.; Ochran, T.G.

    1988-01-01

    A laser alignment system has been developed and tested for air docking applicators to a Siemens ME dedicated intraoperative linear accelerator. A series of three circular anuli collimate the electron beams. The first two anuli are rigidly attached to the collimator. The third anulus is attached to the top of the 30-cm-long treatment cones. A 15-cm air gap separates the cone anulus from the rest of the collimation. The cone is held rigidly to a Marquet surgical table by a Bookwalter clamp. Electrically controlled table motions are used to align the cone with the aid of the laser alignment system. The authors' measurements have shown that a cone angulation of more than 1 0 from true alignment causes significant field asymmetry. However, they have found that the laser system allows repeatable alignment of the cone to better than 0.5 0 . The accuracy and stability of the lasers is therefore quite important. The system's design and evaluation are presented in detail. The evaluation includes isodose distributions fro aligned and misaligned cones

  3. Application of conventional laser technology to gamma-gamma colliders

    International Nuclear Information System (INIS)

    Clayton, C.E.; Kurnit, N.A.; Meyerhofer, D.D.

    1995-01-01

    A future e - e + (electron-positron) linear collider can be configured with perhaps minimal modification to serve as an γ-γ (gamma-gamma) or a e - -γ collider. This is accomplished by Compton-backscattering low energy photons (from a laser source) off of the high-energy electron beams prior to the crossing of the electron beams. However, to be competitive with the e - e + configuration, the luminosity cannot be compromised in the process. This requires that the laser source deliver a sufficient number of photons per pulse with a pulse format and rate matching that of the electron beams. As it turns out, this requires an average optical power of 5 to 15 kW from the laser which is beyond the current state of the art. In this paper, the authors address how to generate the required pulse format and how the high average power requirement can be met with conventional laser technology. They also address concerns about the survivability of mirrors located near the interaction point. Finally, they list a program of research and development which addresses some of the unknowns in such a system

  4. Microgravity Spray Cooling Research for High Powered Laser Applications

    Science.gov (United States)

    Zivich, Chad P.

    2004-01-01

    An extremely powerful laser is being developed at Goddard Space Flight Center for use on a satellite. This laser has several potential applications. One application is to use it for upper atmosphere weather research. In this case, the laser would reflect off aerosols in the upper atmosphere and bounce back to the satellite, where the aerosol velocities could be calculated and thus the upper atmosphere weather patterns could be monitored. A second application would be for the US. Air Force, which wants to use the laser strategically as a weapon for satellite defense. The Air Force fears that in the coming years as more and more nations gain limited space capabilities that American satellites may become targets, and the laser could protect the satellites. Regardless of the ultimate application, however, a critical step along the way to putting the laser in space is finding a way to efficiently cool it. While operating the laser becomes very hot and must be cooled to prevent overheating. On earth, this is accomplished by simply running cool tap water over the laser to keep it cool. But on a satellite, this is too inefficient. This would require too much water mass to be practical. Instead, we are investigating spray cooling as a means to cool the laser in microgravity. Spray cooling requires much less volume of fluid, and thus could be suitable for use on a satellite. We have inherited a 2.2 second Drop Tower rig to conduct our research with. In our experiments, water is pressurized with a compressed air tank and sprayed through a nozzle onto our test plate. We can vary the pressure applied to the water and the temperature of the plate before an experiment trial. The whole process takes place in simulated microgravity in the 2.2 second Drop Tower, and a high speed video camera records the spray as it hits the plate. We have made much progress in the past few weeks on these experiments. The rig originally did not have the capability to heat the test plate, but I did

  5. Spectroscopic characterization of iron-doped II-VI compounds for laser applications

    Science.gov (United States)

    Martinez, Alan

    The middle Infrared (mid-IR) region of the electromagnetic spectrum between 2 and 15 ?m has many features which are of interest to a variety of fields such as molecular spectroscopy, biomedical applications, industrial process control, oil prospecting, free-space communication and defense-related applications. Because of this, there is a demand for broadly tunable, laser sources operating over this spectral region which can be easily and inexpensively produced. II-VI semiconductor materials doped with transition metals (TM) such as Co 2+, Cr2+, or Fe2+ exhibit highly favorable spectroscopic characteristics for mid-IR laser applications. Among these TM dopants, Fe2+ has absorption and emission which extend the farthest into the longer wavelength portion of the mid-IR. Fe2+:II-VI crystals have been utilized as gain elements in laser systems broadly tunable over the 3-5.5 microm range [1] and as saturable absorbers to Q -switch [2] and mode-lock [3] laser cavities operating over the 2.7-3 microm. TM:II-VI laser gain elements can be fabricated inexpensively by means of post-growth thermal diffusion with large homogeneous dopant concentration and good optical quality[4,5]. The work outlined in this dissertation will focus on the spectroscopic characterization of TM-doped II-VI semiconductors. This work can be categorized into three major thrusts: 1) the development of novel laser materials, 2) improving and extending applications of TM:II-VI crystals as saturable absorbers, and 3) fabrication of laser active bulk crystals. Because current laser sources based on TM:II-VI materials do not cover the entire mid-IR spectral region, it is necessary to explore novel laser sources to extend available emissions toward longer wavelengths. The first objective of this dissertation is the spectroscopic characterization of novel ternary host crystals doped with Fe2+ ions. Using crystal field engineering, laser materials can be prepared with emissions placed in spectral regions not

  6. Widely tunable Sampled Grating Distributed Bragg Reflector Quantum Cascade laser for gas spectroscopy applications

    Science.gov (United States)

    Diba, Abdou Salam

    cost and compactness. In this dissertation we investigate the performance of the SG-DBR laser for its feasibility to monitor the atmospheric gases and possible other applications. For this purpose, we first reported continuous mode-hope free tuning and detected three consecutive N2O features by controlling all three sections of laser namely: front DBR, back DBR and the phase. Subsequently, we demonstrated a novel mechanism to tuning the laser wavelength by just controlling the current of front and back DBR sections. From this tuning methodology we achieved continuous tuning over a wide range ~ 10 cm-1. Applying the tuning method in a direct absorption spectroscopy, we demonstrated the viability of SG-DBR QCLs in multi-species gas sensing by detecting and retrieving the concentration of N2O, CO and H2O in ambient air. SG-DBR QCLs capability of high resolution spectroscopy has also been demonstrated at reduced pressure. We also performed Time Resolved Spectroscopy (TRS) to determine the tuning speed response when the DBR sections undergo current steps.

  7. INTERACTION OF RADIATION WITH MATTER. LASER PLASMA: Increase in the amplitude of hf currents during exposure of a neutral target to microsecond CO2 laser pulses

    Science.gov (United States)

    Antipov, A. A.; Losev, Leonid L.; Meshalkin, E. A.

    1988-09-01

    High-frequency electric currents were generated by irradiation of a metal target with CO2 laser pulses. It was found that the region where the ambient gas was photoionized had a decisive influence on the hf current amplitude. A method for increasing the amplitude of the current by creating an auxiliary laser jet on the target was proposed and used. An hf current of up to 1 A amplitude was observed at a frequency of 75 MHz and this current lasted for 1.5 μs.

  8. Towards swift ion bunch acceleration by high-power laser pulses at the Centre for Advanced Laser Applications (CALA)

    Science.gov (United States)

    Lindner, F. H.; Haffa, D.; Bin, J. H.; Englbrecht, F.; Gao, Y.; Gebhard, J.; Hartmann, J.; Hilz, P.; Kreuzer, C.; Lehrack, S.; Ostermayr, T. M.; Rösch, T. F.; Speicher, M.; Würl, M.; Parodi, K.; Schreiber, J.; Thirolf, P. G.

    2017-07-01

    Laser-driven acceleration of ions has inspired novel applications, that can benefit from ion bunch properties different from conventionally (non-laser based) accelerated particle beams. Those differences range from extremely short bunch durations, broad energy spectra, large divergence angles and small source sizes to ultra-high ion bunch densities. So far, the main focus of research has been concentrating on the physics of the interaction of intense laser pulses with plasmas and the related mechanisms of ion acceleration. Now, the new Centre for Advanced Laser Applications (CALA) near Munich aims at pushing these ion bunches towards applications, including radiation therapy of tumors and the development of heavy ion bunches with solid-state-like density. These are needed for novel reaction mechanisms ('fission-fusion') to study the origin of heavy elements in the universe and to prepare for related studies at the upcoming EU-funded high-power laser facility ELI - Nuclear Physics in Bucharest.

  9. A linewidth-narrowed and frequency-stabilized dye laser for application in laser cooling of molecules.

    Science.gov (United States)

    Dai, D P; Xia, Y; Yin, Y N; Yang, X X; Fang, Y F; Li, X J; Yin, J P

    2014-11-17

    We demonstrate a robust and versatile solution for locking the continuous-wave dye laser for applications in laser cooling of molecules which need linewidth-narrowed and frequency-stabilized lasers. The dye laser is first stabilized with respect to a reference cavity by Pound-Drever-Hall (PDH) technique which results in a single frequency with the linewidth 200 kHz and short-term stabilization, by stabilizing the length of the reference cavity to a stabilized helium-neon laser we simultaneously transfer the ± 2 MHz absolute frequency stability of the helium-neon laser to the dye laser with long-term stabilization. This allows the dye laser to be frequency chirped with the maximum 60 GHz scan range while its frequency remains locked. It also offers the advantages of locking at arbitrary dye laser frequencies, having a larger locking capture range and frequency scanning range to be implemented via software. This laser has been developed for the purpose of laser cooling a molecular magnesium fluoride beam.

  10. Extending the wavelength range of single-emitter diode lasers for medical and sensing applications: 12xx-nm quantum dots, 2000-nm wells, > 5000-nm cascade lasers

    Science.gov (United States)

    Crump, Paul; Patterson, Steve; Elim, Sandrio; Zhang, Shiguo; Bougher, Mike; Patterson, Jason; Das, Suhit; Dong, Weimin; Grimshaw, Mike; Wang, Jun; Wise, Damian; DeFranza, Mark; Bell, Jake; Farmer, Jason; DeVito, Mark; Martinsen, Rob; Kovsh, Alexey; Toor, Fatima; Gmachl, Claire F.

    2007-02-01

    Diode lasers supply high power densities at wavelengths from 635-nm to 2000-nm, with different applications enabled by providing this power at different wavelengths. As the range of available wavelengths broadens, many novel medical and atmospheric applications are enabled. Traditional quantum well lasers provide high performance in the range 635- nm to 1100-nm range for GaAs-based devices and 1280-nm to 2000-nm for InP, leaving a notable gap in the 1100 to 1280-nm range. There are many important medical and sensing applications in this range and quantum dots produced using Stranski-Krastanow self-organized MBE growth on GaAs substrates provide an alternative high performance solution. We present results confirming broad area quantum dot lasers can deliver high optical powers of 16-W per emitter and high power conversion efficiency of 35% in this wavelength range. In addition, there are growing applications for high power sources in wavelengths > 1500-nm. We present a brief review of our current performance status in this wavelength range, both with conventional quantum wells in the 1500-nm to 2500-nm range and MOCVD grown quantum cascade lasers for wavelengths > 4000-nm. At each wavelength, we review the designs that deliver this performance, prospects for increased performance and the potential for further broadening the availability of novel wavelengths for high power applications.

  11. Current indications and new applications of intense pulsed light.

    Science.gov (United States)

    González-Rodríguez, A J; Lorente-Gual, R

    2015-06-01

    Intense pulsed light (IPL) systems have evolved since they were introduced into medical practice 20 years ago. Pulsed light is noncoherent, noncollimated, polychromatic light energy emitted at different wavelengths that target specific chromophores. This selective targeting capability makes IPL a versatile therapy with many applications, from the treatment of pigmented or vascular lesions to hair removal and skin rejuvenation. Its large spot size ensures a high skin coverage rate. The nonablative nature of IPL makes it an increasingly attractive alternative for patients unwilling to accept the adverse effects associated with other procedures, which additionally require prolonged absence from work and social activities. In many cases, IPL is similar to laser therapy in effectiveness, and its versatility, convenience, and safety will lead to an expanded range of applications and possibilities in coming years. Copyright © 2014 Elsevier España, S.L.U. and AEDV. All rights reserved.

  12. An overview on current fluid-inclusion research and applications

    Science.gov (United States)

    Chi, G.; Chou, I.-Ming; Lu, H.-Z.

    2003-01-01

    This paper provides an overview of some of the more important developments in fluid-inclusion research and applications in recent years, including fluid-inclusion petrography, PVTX studies, and analytical techniques. In fluid-inclusion petrography, the introduction of the concept of 'fluid-inclusion assemblage' has been a major advance. In PVTX studies, the use of synthetic fluid inclusions and hydrothermal diamond-anvil cells has greatly contributed to the characterization of the phase behaviour of geologically relevant fluid systems. Various analytical methods are being developed and refined rapidly, with the Laser-Raman and LA-ICP-MS techniques being particularly useful for volatile and solute analyses, respectively. Ore deposit research has been and will continue to be the main field of application of fluid inclusions. However, fluid inclusions have been increasingly applied to other fields of earth science, especially in petroleum geology and the study of magmatic and earth interior processes.

  13. [Delivery of megawatts high energy laser pulse with large core diameter silica fiber and its application in dual-wavelength laser-ablation laser-induced breakdown spectroscopy].

    Science.gov (United States)

    Zhou, Qi; Peng, Fei-Fei; Li, Run-Hua; Chen, Yu-Qi; Yang, Xue-Jiao

    2013-12-01

    To resolve the contradiction between spatial resolution and analysis sensitivity in single pulse laser-induced breakdown spectroscopy (LIBS), a study on dual-wavelength laser-ablation laser-induced breakdown spectroscopy (LA-LIBS) was carried out by using one Nd : YAG laser which was capable of two laser beam outputs with different wavelengths, where, the second harmonic output, 532 nm laser beam, was used as laser-ablation source, and the fundamental output, 1064 nm laser beam, was delivered with a large core diameter silica fiber to realize nanoseconds time-delay and then used to breakdown the ablated samples. Two laser beams were orthogonally arranged to realize element analysis with high spatial resolution and high sensitivity. Some key techniques on the coupling of 1064 nm laser beam into fiber, the collimation of laser at the fiber end and re-focusing of the laser beam were studied. The energy delivery capabilities of four fibers of different types were studied and the maximum values were determined experimentally. A Q-switched laser pulse with 15 mJ pulse energy was successfully delivered by selecting a 50 meter long silica fiber with 800 microm core diameter and 0. 39 numerical aperture. And 250 ns time-delay was realized. A copper alloy was analyzed by spectra with current established LA-LIBS system and the possibility of realizing dual-wavelength LA-LIBS analysis based on one Nd : YAG laser was demonstrated experimentally. In this technique, only one Nd: YAG laser was required to carry out spectral analysis. It has a few advantages, such as simple equipment structure, and being convenient to miniaturize the whole system etc. This dual-wavelength LA-LIBS technique was suitable for in-situ elements microanalysis for different samples with both high spatial resolution and high sensitivity.

  14. Bridge Surface Damage Detection Application with a Laser-Based Software Prototype

    Science.gov (United States)

    Güldür Erkal, B.; Apaydın, N. M.

    2017-11-01

    In order to determine the necessary actions such as rehabilitation, repair and etc. required for maintaining the operating status of aging bridges, the current conditions of these structures need to be assessed. Terrestrial laser scanners that are used to capture texture-mapped point clouds have been frequently used for assessing the current conditions of these structures. Authors' have already developed surface damage detection algorithms in their previous work. The developed algorithms are capable of detecting several damage types from the collected texture-mapped point clouds. This short paper focuses on presenting the field application of a recently developed prototype software application that uses the previously developed surface damage detection algorithms. Capabilities of the prototype software application can be listed as importing point clouds, working with images, extracting damage features such as shape and size, determining condition ratings and producing damage reports for future investigations.

  15. Design of laser diode driver with constant current and temperature control system

    Science.gov (United States)

    Wang, Ming-cai; Yang, Kai-yong; Wang, Zhi-guo; Fan, Zhen-fang

    2017-10-01

    A laser Diode (LD) driver with constant current and temperature control system is designed according to the LD working characteristics. We deeply researched the protection circuit and temperature control circuit based on thermos-electric cooler(TEC) cooling circuit and PID algorithm. The driver could realize constant current output and achieve stable temperature control of LD. Real-time feedback control method was adopted in the temperature control system to make LD work on its best temperature point. The output power variety and output wavelength shift of LD caused by current and temperature instability were decreased. Furthermore, the driving current and working temperature is adjustable according to specific requirements. The experiment result showed that the developed LD driver meets the characteristics of LD.

  16. Mapping kA Return Currents in Laser-generated Z-pinch Plasmas

    Science.gov (United States)

    Manuel, M. J.-E.; Sinenian, N.; Séguin, F. H.; Li, C. K.; Frenje, J. A.; Rinderknecht, H. G.; Casey, D. T.; Zylstra, A. B.; Petrasso, R. D.; Fatenejad, M.; Beg, F. N.

    2012-10-01

    During capsule irradiation ``hot'' electrons leave the capsule and a residual positive charge is left on the target. The positive potential, of order 10^6 V, drives a return current through the supporting stalk structure. The first measurements of the spatial extent and magnitude of these return currents were conducted using monoenergetic proton deflectometry. From the measured proton fluence radiographs an absolute current was inferred and shown to increase from ˜2 kA to ˜7 kA during a picketed laser pulse. These images also demonstrate that current begins near the stalk surface and move outward in a similar manner to a single exploding wire Z-pinch. The work described here was done as part of the first author's PhD thesis and supported in part by NLUF (DE-NA0000877), FSC/UR (415023-G), DoE (DE-FG52-09NA29553), LLE (414090-G), and LLNL (B580243).

  17. Laser-induced breakdown spectroscopy fundamentals and applications

    CERN Document Server

    Noll, Reinhard

    2012-01-01

    This book is a comprehensive source of the fundamentals, process parameters, instrumental components and applications of laser-induced breakdown spectroscopy (LIBS). The effect of multiple pulses on material ablation, plasma dynamics and plasma emission is presented. A heuristic plasma modeling allows to simulate complex experimental plasma spectra. These methods and findings form the basis for a variety of applications to perform quantitative multi-element analysis with LIBS. These application potentials of LIBS have really boosted in the last years ranging from bulk analysis of metallic alloys and non-conducting materials, via spatially resolved analysis and depth profiling covering measuring objects in all physical states: gaseous, liquid and solid. Dedicated chapters present LIBS investigations for these tasks with special emphasis on the methodical and instrumental concepts as well as the optimization strategies for a quantitative analysis. Requirements, concepts, design and characteristic features of LI...

  18. The application of cost-effective lasers in coherent UDWDM-OFDM-PON aided by effective phase noise suppression methods.

    Science.gov (United States)

    Liu, Yue; Yang, Chuanchuan; Yang, Feng; Li, Hongbin

    2014-03-24

    Digital coherent passive optical network (PON), especially the coherent orthogonal frequency division multiplexing PON (OFDM-PON), is a strong candidate for the 2nd-stage-next-generation PON (NG-PON2). As is known, OFDM is very sensitive to the laser phase noise which severely limits the application of the cost-effective distributed feedback (DFB) lasers and more energy-efficient vertical cavity surface emitting lasers (VCSEL) in the coherent OFDM-PON. The current long-reach coherent OFDM-PON experiments always choose the expensive external cavity laser (ECL) as the optical source for its narrow linewidth (usuallyOFDM-PON and study the possibility of the application of the DFB lasers and VCSEL in coherent OFDM-PON. A typical long-reach coherent ultra dense wavelength division multiplexing (UDWDM) OFDM-PON has been set up. The numerical results prove that the OBE method can stand severe phase noise of the lasers in this architecture and the DFB lasers as well as VCSEL can be used in coherent OFDM-PON. In this paper, we have also analyzed the performance of the RF-pilot-aided (RFP) phase noise suppression method in coherent OFDM-PON.

  19. High resolution laser beam induced current focusing for photoactive surface characterization

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Lorenzo, C. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Cadiz, Apartado de Correos 40, 11510 Puerto Real, Cadiz (Spain)]. E-mail: concha.fernandez@uca.es; Poce-Fatou, J.A. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Cadiz, Apartado de Correos 40, 11510 Puerto Real, Cadiz (Spain); Alcantara, R. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Cadiz, Apartado de Correos 40, 11510 Puerto Real, Cadiz (Spain); Navas, J. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Cadiz, Apartado de Correos 40, 11510 Puerto Real, Cadiz (Spain); Martin, J. [Departamento de Quimica Fisica, Facultad de Ciencias, Universidad de Cadiz, Apartado de Correos 40, 11510 Puerto Real, Cadiz (Spain)

    2006-12-15

    The micro-characterization of several surface properties of the solar cells can be accomplished using high-resolution laser beam induced current images. For obtaining these images, a very precise laser beam focusing on the photoactive surface is required. For this purpose, a methodology for obtaining the best focalization associated to the maximum of a peak curve has been developed. In this paper, a data set, obtained from the inner photoconversion properties of the system, has been evaluated with three different numerical analysis techniques: (a) derivative (b) length and (c) Fourier Transform, in order to get the finest possible peak distribution. Then, an amount of 13 analytical peak curves using the Levenberg Marquardt algorithm to find the best curve that adjusts the data distribution have been analyzed.

  20. Measuring Earth: Current status of the GRACE Follow-On Laser Ranging Interferometer

    Science.gov (United States)

    Schütze, Daniel; LRI Team

    2016-05-01

    The GRACE mission that was launched in 2002 has impressively proven the feasibility of low-orbit satellite-to-satellite tracking for Earth gravity observations. Especially mass transport related to Earth's hydrological system could be well resolved both spatially and temporally. This allows to study processes such as polar ice sheet decline and ground water depletion in great detail. Owing to GRACE's success, NASA and GFZ will launch the successor mission GRACE Follow-On in 2017. In addition to the microwave ranging system, GRACE Follow-On will be the first mission to use a Laser Ranging Interferometer as technology demonstrator to track intersatellite distance changes with unprecedented precision. This new ranging device inherits some of the technologies which have been developed for the future spaceborne gravitational wave detector LISA. I will present the architecture of the Laser Ranging Interferometer, point out similarities and differences to LISA, and conclude with the current status of the flight hardware production.

  1. Current and Future of Laser Therapy in the Management of Glaucoma

    OpenAIRE

    Ekici, Feyzahan; Waisbourd, Michael; Katz, L. Jay

    2016-01-01

    There has been tremendous progress in the past decades in the utilization of lasers for treating patients with glaucoma. This article reviews the use of lasers in different areas of glaucoma, including the shift from argon laser trabeculoplasty (ALT) to selective laser trabeculoplasty (SLT), laser trabeculoplasty as an initial treatment for glaucoma, new laser trabeculoplasty procedures under investigation, and other recent laser treatment modalities such as endoscopic cyclophotocoagulation a...

  2. Design and optimisation of a pulsed CO2 laser for laser ultrasonic applications

    CSIR Research Space (South Africa)

    Forbes, A

    2006-07-01

    Full Text Available quality, a pulse of short duration (<100 ns), as well as a minimum energy (>200 mJ) and pulse repetition rate (>200 Hz) for the process to be suitable for industrial applications. Furthermore, since these systems will typically be used in a production... ensures a good signal-to-noise ratio, while a higher repetition rate allows more samples to be tested in a given time, thereby increasing productivity. The LU signal is a product of the effi- ciency of the laser pulse in generating ultrasound...

  3. Current concepts on tenogenic differentiation and clinical applications

    Directory of Open Access Journals (Sweden)

    Yang Liu

    2017-04-01

    Full Text Available Tendon is a tissue that transmits force from muscle to bone. Chronic or acute tendon injuries are very common, and are always accompanied by pain and a limited range of motion in patients. In clinical settings, management of tendon injuries still remains a big challenge. Cell therapies, such as the application of stem cells for tenogenic differentiation, were suggested to be an ideal strategy for clinical translation. However, there is still a lack of specific methods for tenogenic differentiation due to the limited understanding of tendon biology currently. This review focuses on the summary of current published strategies for tenogenic differentiation, such as the application of growth factors, mechanical stimulation, biomaterials, coculture, or induced pluripotent stem cells. Current clinical applications of stem cells for treatment of tendon injuries and their limitations have also been discussed in this review.

  4. A positioning free calibration method for mobile laser scanning applications

    Directory of Open Access Journals (Sweden)

    R. Le Scouarnec

    2013-10-01

    Full Text Available Mobile laser scanning are likely to find more and more applications for high density 3D environmental data. A mobile laser scanning system is composed by three subsystems: a GNSS (Global Navigation Satellite System that provides position information, an INS (Inertial Navigation System for attitude determination, and a LiDAR (Light Detection And Ranging. The accuracy of the geolocated LiDAR returns depends on the accuracy of each instrument but also on the bore-sighting parameters and the lever arms between the instruments. Indeed, an imperfect calibration may lead to systematic errors. Calibration may then become the limiting factor of Terrestrial Laser scanning if it is not tackled seriously. Moreover [Ø], it is important to have a reliable value of the calibration precision. This paper presents a new positioning free procedure for the estimation of the LiDAR bore-sighting parameters. Since this method is static, lever arms do not affect the boresight calibration and positioning is not required. That makes the methodology immune to GPS errors. Finally, since it is based on a rigorous mathematical model, it can provide a reliable boresight quality factor. First, the boresight determination problem is explained and existing calibration procedures are introduced. After having explained their drawbacks, a new procedure that tries to overcome these limitations is described. Tests from simulations and real datasets are also presented to illustrate our approach.

  5. Laser development for laser fusion applications research. Progress report, October 1977--March 1978

    Energy Technology Data Exchange (ETDEWEB)

    1978-06-01

    Research progress is reported on three laser programs being developed for the commercialization of laser-fusion energy. The lasers include iodine, hydrogen fluoride and Group VI atoms (e.g., O, S, Se, Te). (TFD)

  6. Laser development for laser fusion applications research. Progress report, October 1977--March 1978

    International Nuclear Information System (INIS)

    1978-06-01

    Research progress is reported on three laser programs being developed for the commercialization of laser-fusion energy. The lasers include iodine, hydrogen fluoride and Group VI atoms (e.g., O, S, Se, Te)

  7. The performance and application of laser-induced photoacoustic spectrometer

    International Nuclear Information System (INIS)

    Wang Bo; Chen Xi; Yao Jun

    2012-01-01

    Laser-induced photoacoustic spectrometer (LIPAS) is a key instrument can be used in the investigation of radionuclides migration behaviors due to its higher sensitivity for the detection and identification of radionuclides speciation in aqueous solutions. The speciation of radionuclides such as oxidation states and complexation may be determined directly by using this specific non-contact and nondestructive analytical technique, and the sensitivity of LIPAS surpasses that of conventional absorption spectroscopy by one to two orders of magnitude. In the present work, LIPAS system was established at China Institute of Atomic Energy (CIAE), and the principle, performance and preliminary application of LIPAS are also be presented. (authors)

  8. Center of Excellence for Laser Applications in Medicine, Microlaser Microscope

    Energy Technology Data Exchange (ETDEWEB)

    Webb, R. H.

    2003-01-17

    The Center of Excellence for Laser Applications in Medicine at the Schepens Eye Research Institute (SERI) is a Center for: A core group of researchers who support each other and their various projects for real-time medical imaging and diagnostics in contiguous space at SERI. Clinical collaborators who participate in the core research at SERI, MEEI, and local ophthalmology practices, and at associated sites around the world. Industrial partners who transfer our technology to commercial products that will reach clinical usage everywhere. Students, post-doctoral associates and medical fellows who work with us and learn how to practice real-time medical imaging and diagnostics.

  9. Atomic Physics at Accelerators Laser Spectroscopy and Applications

    CERN Document Server

    Letokhov, V

    2003-01-01

    From 19 to 24 September, 1999, the First European Conference Atomic physics at Accelerators: Laser Spectroscopy and Applications (APAC'99) was held at University of Mainz and Schloss Waldhausen (Budenheim, Germany) under the chairmanship of H. Backe and G. Huber. The idea of this up-to-date conference was associated with the 65th anniversary of Professor Ernst Otten (University of Mainz) who, together with H. Kluge, contributed much to the development of this work at CERN, University of Mainz, and Darmstadt. (17 refs).

  10. Application Of CO2 Lasers To High Speed Blanking

    Science.gov (United States)

    Grenier, L. E.

    1986-11-01

    While laser cutting of sheetmetal has attained wide acceptance in the automotive industry for the purposes of prototyping and very limited preproduction work, the production rates possible with currently available systems have precluded the use of this technique in a production environment. The device design to be described embodies a high speed X-Y positioner carrying a cutting head with limited Z-axis capability. This approach confers two main benefits, first, production rate is limited only by laser power, since the positioner technology selected will permit movement at rates up to 1.5 m/s (60 in/s), second, the use of a high speed non-contact surface follower to control the Z-axis movement reduces the need to clamp the workpiece rigidly to a precision reference surface. The realized reduction of the clamping requirement permits some latitude in the feed methods that can be employed, allowing the use of coil or sheet feeding as appropriate. The author will provide estimated production rates for the proposed design and demonstrate that a suitable choice of laser source and material feed will permit the production of parts at a rate and cost comparable to conventional blanking with the advantage of much greater flexibility and reduced retooling time.

  11. Pulse current gas metal arc welding characteristics, control and applications

    CERN Document Server

    Ghosh, Prakriti Kumar

    2017-01-01

    This monograph is a first-of-its-kind compilation on high deposition pulse current GMAW process. The nine chapters of this monograph may serve as a comprehensive knowledge tool to use advanced welding engineering in prospective applications. The contents of this book will prove useful to the shop floor welding engineer in handling this otherwise critical welding process with confidence. It will also serve to inspire researchers to think critically on more versatile applications of the unique nature of pulse current in GMAW process to develop cutting edge welding technology.

  12. The electromagnetic spectrum: current and future applications in oncology.

    Science.gov (United States)

    Allison, Ron R

    2013-05-01

    The electromagnetic spectrum is composed of waves of various energies that interact with matter. When focused upon and directed at tumors, these energy sources can be employed as a means of lesion ablation. While the use of x-rays is widely known in this regard, a growing body of evidence shows that other members of this family can also achieve oncologic success. This article will review therapeutic application of the electromagnetic spectrum in current interventions and potential future applications.

  13. High-speed circuits for TE discharge lasers and high-voltage applications

    Science.gov (United States)

    Houtman, H.; Cheuck, A.; Elezzabi, A. Y.; Ford, J. E.; Laberge, M.; Liese, W.; Meyer, J.; Stuart, G. C.; Zhu, Y.

    1993-04-01

    Pulsed transverse electric (TE) glow discharges used to produce population inversions in gas lasers at 1-20 atm require high-speed, high-voltage, high-current capacitor banks. In this article we first review and compare the circuits in common use to produce the required fast, self-sustained glow discharges in CO2, excimer, and N2 lasers. The parameters and circuit types given will be useful to future designers of pulsed gas lasers to design and to optimize any proposed circuit in order to yield any desired operating conditions and parameters. The n-stage circuit types presented are capacitor-transfer (C-C), L-C inversion, Marx bank, and fourfold L-C inversion, with their double-sided counterparts, and also their transmission-line counterparts, such as the Blumlein circuit. A one-parameter differential equation is developed which describes the general series C-L-R circuit. Electrical pulses measured on various lasers are compared with the differential equation solutions for various bank impedances and load resistances. We then present the design and measurements of a new automatically preionized, double-sided, L-C inversion circuit for an 800-mJ, TE CO2 laser, and compare it to previous systems. Methods to lengthen the discharge pulse, and some novel active mode locking techniques are discussed. We compare the L-C inversion circuit, the fourfold L-C inversion circuit, the conventional Marx bank, and the ``double Marx bank'' for lasers and other applications, such as pulsed particle accelerators. Finally, we discuss capacitor bank interconnections, electro-optic probe systems, and various triggering methods.

  14. Nanomaterials in Food - Current and Future Applications and Regulatory Aspects

    International Nuclear Information System (INIS)

    Aschberger, K; Gottardo, S; Amenta, V; Arena, M; Moniz, F Botelho; Mech, A; Pesudo, L Quiros; Rauscher, H; Bouwmeester, H; Brandhoff, P; Peters, R; Schoonjans, R; Vettori, M Vittoria

    2015-01-01

    Nanotechnology can contribute to the development of innovative applications in the agriculture, food and feed sector by e.g. enabling improved delivery of nutrients or increased efficacy of agrichemicals. It is expected that applications will increase in the near future and may therefore become a relevant source of human exposure to nanomaterials (NM). To gain more up-to date information, RIKILT and the Joint Research Centre (JRC) were commissioned by the European Food Safety Authority (EFSA) to prepare an inventory of currently used and reasonably foreseen applications of NM in agriculture and food/feed production and carried out a review of regulatory aspects concerning NM in both EU and non-EU countries. An analysis of the information records in the inventory shows that nano-encapsulates, silver and titanium dioxide are the most frequent type of NM listed and that food additives and food contact materials are the most frequent types of application. A comparison between marketed applications and those in development indicates a trend from inorganic materials (e.g. silver) towards organic materials (nano-encapsulates, nanocomposites). Applications in novel food, feed additives, biocides and pesticides are currently mostly at a developmental stage. The review of EU and non-EU legislation shows that currently a few EU legal acts incorporate a definition of a nanomaterial and specific provisions for NM, whereas in many non-EU countries a broader approach is applied, which mainly builds on guidance for industry. (paper)

  15. Nanomaterials in Food - Current and Future Applications and Regulatory Aspects

    Science.gov (United States)

    Aschberger, K.; Gottardo, S.; Amenta, V.; Arena, M.; Botelho Moniz, F.; Bouwmeester, H.; Brandhoff, P.; Mech, A.; Quiros Pesudo, L.; Rauscher, H.; Schoonjans, R.; Vittoria Vettori, M.; Peters, R.

    2015-05-01

    Nanotechnology can contribute to the development of innovative applications in the agriculture, food and feed sector by e.g. enabling improved delivery of nutrients or increased efficacy of agrichemicals. It is expected that applications will increase in the near future and may therefore become a relevant source of human exposure to nanomaterials (NM). To gain more up-to date information, RIKILT and the Joint Research Centre (JRC) were commissioned by the European Food Safety Authority (EFSA) to prepare an inventory of currently used and reasonably foreseen applications of NM in agriculture and food/feed production and carried out a review of regulatory aspects concerning NM in both EU and non-EU countries. An analysis of the information records in the inventory shows that nano-encapsulates, silver and titanium dioxide are the most frequent type of NM listed and that food additives and food contact materials are the most frequent types of application. A comparison between marketed applications and those in development indicates a trend from inorganic materials (e.g. silver) towards organic materials (nano-encapsulates, nanocomposites). Applications in novel food, feed additives, biocides and pesticides are currently mostly at a developmental stage. The review of EU and non-EU legislation shows that currently a few EU legal acts incorporate a definition of a nanomaterial and specific provisions for NM, whereas in many non-EU countries a broader approach is applied, which mainly builds on guidance for industry.

  16. LASER APPLICATIONS AND OTHER TOPICS IN QUANTUM ELECTRONICS: Laser-induced extreme UV radiation sources for manufacturing next-generation integrated circuits

    Science.gov (United States)

    Borisov, V. M.; Vinokhodov, A. Yu; Ivanov, A. S.; Kiryukhin, Yu B.; Mishchenko, V. A.; Prokof'ev, A. V.; Khristoforov, O. B.

    2009-10-01

    The development of high-power discharge sources emitting in the 13.5±0.135-nm spectral band is of current interest because they are promising for applications in industrial EUV (extreme ultraviolet) lithography for manufacturing integrated circuits according to technological precision standards of 22 nm and smaller. The parameters of EUV sources based on a laser-induced discharge in tin vapours between rotating disc electrodes are investigated. The properties of the discharge initiation by laser radiation at different wavelengths are established and the laser pulse parameters providing the maximum energy characteristics of the EUV source are determined. The EUV source developed in the study emits an average power of 276 W in the 13.5±0.135-nm spectral band on conversion to the solid angle 2π sr in the stationary regime at a pulse repetition rate of 3000 Hz.

  17. Rugged and compact mid-infrared solid-state laser for avionics applications

    CSIR Research Space (South Africa)

    Esser, MJD

    2009-11-01

    Full Text Available In order to demonstrate the feasibility of a helicopter-based application using advanced laser technology, the authors have developed a rugged and compact mid-infrared solid-state laser. The requirement for the laser was to simultaneously emit at 2...

  18. Novel Aspects of Materials Processing by Ultrafast Lasers: From Electronic to Biological and Cultural Heritage Applications

    International Nuclear Information System (INIS)

    Fotakis, C; Zorba, V; Stratakis, E; Athanassiou, A; Tzanetakis, P; Zergioti, I; Papagoglou, D G; Sambani, K; Filippidis, G; Farsari, M; Pouli, V; Bounos, G; Georgiou, S

    2007-01-01

    Materials processing by ultrafast lasers offers several distinct possibilities for micro/nano scale applications. This is due to the unique characteristics of the laser-matter interactions involved, when sub-picosecond pulses are employed. Prospects arising will be discussed in the context of surface and in bulk laser induced modifications. In particular, examples of diverse applications including the development and functionalization of laser engineered surfaces, the laser transfer of biomolecules and the functionalization of 3D structures constructed by three-photon stereolithography will be presented. Furthermore, the removal of molecular substrates by ultrafast laser ablation will be discussed with emphasis placed on assessing the photochemical changes induced in the remaining bulk material. The results indicate that in femtosecond laser processing of organic materials, besides the well acknowledged morphological advantages, a second fundamental factor responsible for its success pertains to the selective chemical effects. This is crucial for the laser cleaning of sensitive painted artworks

  19. Nanostructures: Current uses and future applications in food science.

    Science.gov (United States)

    Pathakoti, Kavitha; Manubolu, Manjunath; Hwang, Huey-Min

    2017-04-01

    Recent developments in nanoscience and nanotechnology intend novel and innovative applications in the food sector, which is rather recent compared with their use in biomedical and pharmaceutical applications. Nanostructured materials are having applications in various sectors of the food science comprising nanosensors, new packaging materials, and encapsulated food components. Nanostructured systems in food include polymeric nanoparticles, liposomes, nanoemulsions, and microemulsions. These materials enhance solubility, improve bioavailability, facilitate controlled release, and protect bioactive components during manufacture and storage. This review highlights the applications of nanostructured materials for their antimicrobial activity and possible mechanism of action against bacteria, including reactive oxygen species, membrane damage, and release of metal ions. In addition, an overview of nanostructured materials, and their current applications and future perspectives in food science are also presented. Copyright © 2017. Published by Elsevier B.V.

  20. Hole dynamics and spin currents after ionization in strong circularly polarized laser fields

    International Nuclear Information System (INIS)

    Barth, Ingo; Smirnova, Olga

    2014-01-01

    We apply the time-dependent analytical R-matrix theory to develop a movie of hole motion in a Kr atom upon ionization by strong circularly polarized field. We find rich hole dynamics, ranging from rotation to swinging motion. The motion of the hole depends on the final energy and the spin of the photoelectron and can be controlled by the laser frequency and intensity. Crucially, hole rotation is a purely non-adiabatic effect, completely missing in the framework of quasistatic (adiabatic) tunneling theories. We explore the possibility to use hole rotation as a clock for measuring ionization time. Analyzing the relationship between the relative phases in different ionization channels we show that in the case of short-range electron-core interaction the hole is always initially aligned along the instantaneous direction of the laser field, signifying zero delays in ionization. Finally, we show that strong-field ionization in circular fields creates spin currents (i.e. different flow of spin-up and spin-down density in space) in the ions. This phenomenon is intimately related to the production of spin-polarized electrons in strong laser fields Barth and Smirnova (2013 Phys. Rev. A 88 013401). We demonstrate that rich spin dynamics of electrons and holes produced during strong field ionization can occur in typical experimental conditions and does not require relativistic intensities or strong magnetic fields. (paper)

  1. Alternative applications of atomic vapor laser isotope separation technology

    International Nuclear Information System (INIS)

    1991-01-01

    This report was commissioned by the Secretary of Energy. It summarizes the main features of atomic vapor laser isotope separation (AVLIS) technology and subsystems; evaluates applications, beyond those of uranium enrichment, suggested by Lawrence Livermore National Laboratory (LLNL) and a wide range of US industries and individuals; recommends further work on several applications; recommends the provision of facilities for evaluating potential new applications; and recommends the full involvement of end users from the very beginning in the development of any application. Specifically excluded from this report is an evaluation of the main AVLIS missions, uranium enrichment and purification of plutonium for weapons. In evaluating many of the alternative applications, it became clear that industry should play a greater and earlier role in the definition and development of technologies with the Department of Energy (DOE) if the nation is to derive significant commercial benefit. Applications of AVLIS to the separation of alternate (nonuranium) isotopes were considered. The use of 157 Gd as burnable poison in the nuclear fuel cycle, the use 12 C for isotopically pure diamond, and the use of plutonium isotopes for several nonweapons applications are examples of commercially useful products that might be produced at a cost less than the product value. Separations of other isotopes such as the elemental constituents of semiconductors were suggested; it is recommended that proposed applications be tested by using existing supplies to establish their value before more efficient enrichment processes are developed. Some applications are clear, but their production costs are too high, the window of opportunity in the market has passed, or societal constraints (e.g., on reprocessing of reactor fuel) discourage implementation

  2. Spectral and temporal characteristics of target current and electromagnetic pulse induced by nanosecond laser ablation

    Czech Academy of Sciences Publication Activity Database

    Krása, Josef; De Marco, Massimo; Cikhardt, Jakub; Pfeifer, Miroslav; Velyhan, Andriy; Klír, Daniel; Řezáč, Karel; Limpouch, J.; Krouský, Eduard; Dostál, Jan; Ullschmied, Jiří; Dudžák, Roman

    2017-01-01

    Roč. 59, č. 6 (2017), 1-8, č. článku 065007. ISSN 0741-3335 R&D Projects: GA MŠk EF15_008/0000162; GA ČR GA16-07036S EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE Grant - others:ELI Beamlines(XE) CZ.02.1.01/0.0/0.0/15_008/0000162 Institutional support: RVO:68378271 ; RVO:61389021 Keywords : laser-produced plasma * target current * electromagnetic pulse Subject RIV: BL - Plasma and Gas Discharge Physics OBOR OECD: Fluids and plasma physics (including surface physics) Impact factor: 2.392, year: 2016

  3. Laser beam joining of material combinations for automotive applications

    Science.gov (United States)

    Schubert, Emil; Zerner, Ingo; Sepold, Gerd

    1997-08-01

    An ideal material for automotive applications would combine the following properties: high corrosion resistance, high strength, high stiffness and not at least a low material price. Today a single material is not able to meet all these requirements. Therefore, in the future different materials will be placed where they meet the requirements best. The result of this consideration is a car body with many different alloys and metals, which have to be joined to one another. BIAS is working on the development of laser based joining technologies for different material combinations, especially for thin sheets used in automotive applications. One result of the research is a joining technology for an aluminum-steel-joint. Using a Nd:YAG laser the problem of brittle intermetallic phases between these materials was overcome. Using suitable temperature-time cycles, elected by a FEM-simulation, the thickness of intermetallic phases was kept below 10 micrometers . This technology was also applied to coated steels, which were joined with different aluminum alloys. Further it is demonstrated that titanium alloys, e.g. used for racing cars, can also be joined with aluminum alloys.

  4. New generation of gimbals systems for laser positioning applications

    Science.gov (United States)

    Sofka, Jozef; Skormin, Victor A.; Nikulin, Vladimir V.; Nicholson, Donald J.; Rosheim, Mark

    2004-01-01

    Omniwrist III is a new sensor mount developed under Air Force funding that emulates the kinematics of a human wrist. Driven by two linear motors and computer controlled, it is capable of a full 180° hemisphere of pitch/yaw motion. A comprehensive laboratory testing of one of few existing devices of this type, installed in the Laser Research Laboratory at Binghamton University, has resulted in the establishment of a complete transfer matrix-type model relating pitch/yaw coordinates of the sensor mount to the voltage signals applied to the motors. Although dynamic characteristics of the device are position-dependent, it has the potential for exceeding bandwidth and positioning accuracy of a traditional gimbals system at least by the factor of ten. The device is suitable for the application of the most advanced control strategies that will result in the further enhancement of its dynamic performance thus extending the scope of its application to various problems of satellite communications, LADAR, laser weapon systems, etc. This study is aimed at the investigation of the best performance characteristics (bandwidth, tracking error, cross-coupling effects, etc.) attainable under advanced control laws. The authors intend to consider implementation of such control laws as optimal control utilizing dynamic programming, gain scheduling, and fuzzy logic control. The results of this research will be incorporated in the future papers. It is shown that Omniwrist III with the appropriate controls could be considered as a new generation of gimbals system.

  5. Reflecting on current applications of design for behaviour change

    NARCIS (Netherlands)

    Niedderer, Kristina; Clune, Stephen; Ludden, Geke; Niedderer, Kristina; Clune, Stephen; Ludden, Geke

    2017-01-01

    This chapter reviews the current engagement with and applications of design for behaviour change approaches reported in the preceding five chapters. The chapter begins with an overview of design for behaviour change models, processes and tools that have been applied within the five domains of

  6. Plant cell engineering: current research, application and future prospects

    International Nuclear Information System (INIS)

    Wang Xunqing; Liu Luxiang

    2008-01-01

    This paper reviewed the current status of basic research in plant cell engineering, highlighted the application of embryo culture, double haploid (DH) technology, protoplast culture and somatic hybridization, somaclonal variation, rapid propagation, and bio-products production of plant-origin, and t he prospects. (authors)

  7. Nanomedicines for renal disease: current status and future applications

    DEFF Research Database (Denmark)

    Kamaly, Nazila; He, John C.; Ausiello, Dennis A.

    2016-01-01

    Treatment and management of kidney disease currently presents an enormous global burden, and the application of nanotechnology principles to renal disease therapy, although still at an early stage, has profound transformative potential. The increasing translation of nanomedicines to the clinic, a...

  8. Design of a compact application-oriented free-electron laser

    International Nuclear Information System (INIS)

    Chan, K.C.D.; Meier, K.; Nguyen, D.; Sheffield, R.; Wang, T.S.; Warren, R.W.; Wilson, W.; Young, L.M.

    1992-01-01

    The goal of the Advanced Free-Electron Laser Project at the Los Alamos National Laboratory is to demonstrate that a free-electron laser (FEL) suitable for industrial, medical, and research applications can be built. This FEL system should be efficient, compact, robust, and user-friendly. To achieve this goal, we have incorporated advanced components presently available. Electrons produced by a photoelectron source are accelerated to 20 MeV by a high-brightness accelerator. They are transported by an emittance-preserving beamline with permanent-magnet quadrupoles and dipoles. The electron beam has excellent instantaneous beam quality better than: 2.5 π mm mrad in transverse emittance and 0.3% in energy spread at a Peak current up to 310 A. It is used to excite a FEL oscillator with a pulsed-current microwiggler. Including operation at higher harmonics, the laser wavelength extends from 3.7 μm to 0.4 μm

  9. The laser: a concentrate of light. From the creation of a beam to its applications

    International Nuclear Information System (INIS)

    2005-04-01

    The first lasers were developed in the 1960's. The name LASER is an acronym for 'Light Amplification by the Stimulated Emission of Radiation'. The almost magical properties of laser light soon led to their use in a variety of applications. We use lasers every day in our CD players and in the bar-code readers used in supermarkets. Laser light shows create beautiful patterns of light in the air. Lasers are also precision workers in industry. They are used to cut, weld and drill materials. They are used in medicine to repair or burn away diseased tissue without harming healthy tissue nearby. Straight and narrow laser beams are also used to align roads and tunnels. But why is it that lasers can do all these things while ordinary light from the Sun or from a light bulb cannot? 'Lasers are everywhere - in medicine, in industry, and at the heart of our daily lives'. CEA has worked on all types of lasers for many years. CEA researchers use them in their work in all the traditional ways (alignment, drilling, welding, cutting, etc.), but they also develop new types of lasers for specific applications. They use very high power lasers to study the interaction between high energies and matter. Lasers are essential tools in many applications, but we must never forget the risks that are associated with them. The CEA is studying the effects of lasers on the body. There is still much research to be done in the field of laser technology. We expect more and more applications in the next few years. (authors)

  10. Marine current energy devices: Current status and possible future applications in Ireland

    Energy Technology Data Exchange (ETDEWEB)

    Rourke, Fergal O.; Boyle, Fergal; Reynolds, Anthony [Department of Mechanical Engineering, Dublin Institute of Technology, Bolton Street, Dublin 1 (Ireland)

    2010-04-15

    There is a growing demand for the use of renewable energy technologies to generate electricity due to concerns over climate change. The oceans provide a huge potential resource of energy. Energy extraction using marine current energy devices (MCEDs) offers a sustainable alternative to conventional sources and a predictable alternative to other renewable energy technologies. A MCED utilises the kinetic energy of the tides as opposed to the potential energy which is utilised by a tidal barrage. Over the past decade MCEDs have become an increasingly popular method of energy extraction. However, marine current energy technology is still not economically viable on a large scale due to its current stage of development. Ireland has an excellent marine current energy resource as it is an island nation and experiences excellent marine current flows. This paper reviews marine current energy devices, including a detailed up-to-date description of the current status of development. Issues such as network integration, economics, and environmental implications are addressed as well as the application and costs of MCEDs in Ireland. (author)

  11. Injection moulding of plastic parts with laser textured surfaces with optical applications

    Science.gov (United States)

    Pina-Estany, J.; García-Granada, A. A.; Corull-Massana, E.

    2018-05-01

    The purpose of this work is to manufacture micro and nanotextured surfaces on plastic injection moulds with the aim of replicating them and obtaining plastic parts with optical applications. Different patterns are manufactured with nanosecond and femtosecond lasers in order to obtain three different optical applications: (i) homogeneous light diffusion (ii) 1D light directionality and (iii) 2D light directionality. Induction heating is used in the injections in order to improve the textures degree of replication. The steel mould and the plastic parts are analyzed with a confocal/focus variation microscope and with a surface roughness tester. A mock-up and a luminance camera are used to evaluate the homogeneity and luminance of the homogeneous light diffusion application in comparison with the current industrial solutions.

  12. High-Speed, Radiation-Tolerant Laser Drivers in 0.13 μm CMOS Technology for HEP Applications

    Science.gov (United States)

    Mazza, Giovanni; Tavernier, Filip; Moreira, Paulo; Calvo, Daniela; De Remigis, Paolo; Olantera, Lauri; Soos, Csaba; Troska, Jan; Wyllie, Ken

    2014-12-01

    The gigabit laser driver (GBLD) and low-power GBLD (LpGBLD) are two radiation-tolerant laser drivers designed to drive laser diodes at data rates up to 4.8 Gb/s. They have been designed in the framework of the gigabit-transceiver (GBT) and versatile-link projects to provide fast optical links capable of operation in the radiation environment of future high-luminosity high-energy physics experiments. The GBLD provides laser bias and modulation currents up to 43 mA and 24 mA, respectively. It can thus be used to drive vertical cavity surface emitting laser (VCSEL) and edge-emitting laser diodes. A pre-emphasis circuit, which can provide up to 12 mA in 70 ps pulses, has also been implemented to compensate for high external capacitive loads. The current driving capabilities of the LpGBLD are 2 times smaller that those of the GBLD as it has been optimized to drive VCSELs in order to minimize the power consumption. Both application-specific integrated circuits are designed in 0.13 μm commercial complementary metal-oxide semiconductor technology and are powered by a single 2.5 V supply. The power consumption of the core circuit is 89 mW for the GBLD and 55 mW for the LpGBLD.

  13. High-Speed, Radiation-Tolerant Laser Drivers in 0.13 $\\mu$m CMOS Technology for HEP Applications

    CERN Document Server

    AUTHOR|(CDS)2073369; Moreira, Paulo; Calvo, Daniela; De Remigis, Paolo; Olantera, Lauri; Soos, Csaba; Troska, Jan; Wyllie, Ken

    2014-01-01

    The gigabit laser driver (GBLD) and low-power GBLD (LpGBLD) are two radiation-tolerant laser drivers designed to drive laser diodes at data rates up to 4.8 Gb/s. They have been designed in the framework of the gigabit-transceiver (GBT) and versatile-link projects to provide fast optical links capable of operation in the radiation environment of future high-luminosity high-energy physics experiments. The GBLD provides laser bias and modulation currents up to 43 mA and 24 mA, respectively. It can thus be used to drive vertical cavity surface emitting laser (VCSEL) and edge-emitting laser diodes. A pre-emphasis circuit, which can provide up to 12 mA in 70 ps pulses, has also been implemented to compensate for high external capacitive loads. The current driving capabilities of the LpGBLD are 2 times smaller that those of the GBLD as it has been optimized to drive VCSELs in order to minimize the power consumption. Both application-specific integrated circuits are designed in 0.13 m commercial complementary metal-o...

  14. Development of a Low SWaP Laser Transmitter for lidar applications

    Science.gov (United States)

    Prasad, N.; Rosiewicz, A.; Coleman, S.

    2009-12-01

    NASA Langley Research Center (LaRC) is working on novel lidar schemes to measure carbon dioxide concentrations from space based platforms for Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission. The National Research Council of the U.S. National Academies in its Decadal Survey, Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond, has recommended the ASCENDS mission to produce global atmospheric column CO2 measurements without seasonal, latitudinal, or diurnal bias using simultaneous laser remote sensing of CO2 and O2. The goal the ASCENDS mission is to enhance understanding of the role of CO2 in the global carbon cycle that include quantification of global spatial distributions of terrestrial and oceanic sources and sinks of CO2 on 1° x 1° grids. Accurate measurements of atmospheric parameters with high-spatial resolution from ground, airborne, and space-based platforms require advances in the state-of-the-art LIDAR technology with emphasis on compactness, efficiency, reliability, lifetime, and high performance. LaRC has selected the 1.57 micron spectral band for CO2 and 1.26 micron spectral band for oxygen sensing. In this paper, we discuss recent progress made in the development of compact, single mode transmitter technologies for CO2 and O2 lidars. One of our efforts is to demonstrate compact, efficient DFB laser modules with integrated drive and temperature control circuitry that minimizes laser linewidth, allows for wavelength tunability, and is adaptable to space qualified electronic hardware. Since ASCENDS is in essence a spectroscopic mission, precise tunability of the laser diode wavelength over transition lines is of importance. The overall goal is to reduce the overall size, weight, and power consumption (SWaP) of the laser master oscillator. In this paper, the development of advanced DFB laser diode module efficiently coupled to integrated electronics and nano-cooling scheme in a

  15. A Fiber-Optic Current Sensor for Lightning Measurement Applications

    Science.gov (United States)

    Nguyen, Truong X.; Ely, Jay J.; Szatkowski, George N.

    2015-01-01

    An optical-fiber sensor based on Faraday Effect is developed for measuring total lightning electric current. It has many unique capabilities not possible with traditional current sensors. Designed for aircraft installation, the sensor is lightweight, non-conducting, structure-conforming, and is immune to electromagnetic interference, hysteresis and saturation. It can also be used on windmills, lightning towers, and can help validate lightning detection network measurements. Faraday Effect causes light polarization to rotate when the fiber is exposed to a magnetic field in the direction of light propagation. Thus, the magnetic field strength can be determined from the light polarization change. By forming closed fiber loops and applying Ampere's law, measuring the total light rotation yields the total current enclosed. The broadband, dual-detector, reflective polarimetric scheme allows measurement of both DC component and AC waveforms with about 60 dB dynamic range. Three sensor systems were built with different sensitivities from different laser wavelengths. Operating at 850nm, the first system uses twisted single-mode fiber and has a 150 A - 150 KA range. The second system operates at 1550nm, uses spun polarization maintaining fiber, and can measure 400 A - 400 KA. Both systems were validated with rocket-triggered lightning measurements and achieved excellent results when compared to a resistive shunt. The third system operates at 1310nm, uses spun polarization maintaining fiber, and can measure approximately 300 A - 300 KA. High current measurements up to 200 KA were demonstrated at a commercial lightning test facility. The system was recently installed on an aircraft and flown near icing weather conditions.

  16. LASER BIOLOGY AND MEDICINE: Application of tunable diode lasers for a highly sensitive analysis of gaseous biomarkers in exhaled air

    Science.gov (United States)

    Stepanov, E. V.; Milyaev, Varerii A.

    2002-11-01

    The application of tunable diode lasers for a highly sensitive analysis of gaseous biomarkers in exhaled air in biomedical diagnostics is discussed. The principle of operation and the design of a laser analyser for studying the composition of exhaled air are described. The results of detection of gaseous biomarkers in exhaled air, including clinical studies, which demonstrate the diagnostic possibilities of the method, are presented.

  17. A LIGHT-WEIGHT LASER SCANNER FOR UAV APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A. M. G. Tommaselli

    2016-06-01

    Full Text Available Unmanned Aerial Vehicles (UAV have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  18. a Light-Weight Laser Scanner for Uav Applications

    Science.gov (United States)

    Tommaselli, A. M. G.; Torres, F. M.

    2016-06-01

    Unmanned Aerial Vehicles (UAV) have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP) as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  19. Edge-emitting InGaAs/GaAs laser with high temperature stability of wavelength and threshold current

    International Nuclear Information System (INIS)

    Gordeev, N Yu; Novikov, I I; Chunareva, A V; Il'inskaya, N D; Shernyakov, Yu M; Maximov, M V; Kalyuzhnyy, N A; Mintairov, S A; Lantratov, V M; Payusov, A S; Shchukin, V A; Ledentsov, N N

    2010-01-01

    We have investigated an edge-emitting tilted wave laser (TWL) with the active region based on GaInAs/GaAs quantum wells. In the TWL the wavelength stabilization is based on the coupling of the laser active waveguide cavity to a specially introduced thick epitaxial layer and the emission wavelength is defined by the combined cavity mode preferably by a single dominating mode. The TWL wafer has been grown by metal-organic chemical vapour deposition. Laser parameters have been investigated both in pulsed and CW mode in the temperature range of 15–60 °C. In the temperature window of 20–50 °C under CW excitation the lasers have shown high wavelength temperature stability with the temperature shift of 0.05 nm K −1 and threshold current stability with the characteristic temperature of 500 K. The data obtained prove the concept of thermal stability in tilted wave lasers

  20. Two novel applications of bootstrap currents: Snakes and jitter stabilization

    Science.gov (United States)

    Thyagaraja, A.; Haas, F. A.

    1993-09-01

    Both neoclassical theory and certain turbulence theories of particle transport in tokamaks predict the existence of bootstrap (i.e., pressure-driven) currents. Two new applications of this form of noninductive current are considered in this work. In the first, an earlier model of the nonlinearly saturated m=1 tearing mode is extended to include the stabilizing effect of a bootstrap current inside the island. This is used to explain several observed features of the so-called ``snake'' reported in the Joint European Torus (JET) [R. D. Gill, A. W. Edwards, D. Pasini, and A. Weller, Nucl. Fusion 32, 723 (1992)]. The second application involves an alternating current (ac) form of bootstrap current, produced by pressure-gradient fluctuations. It is suggested that a time-dependent (in the plasma frame), radio-frequency (rf) power source can be used to produce localized pressure fluctuations of suitable frequency and amplitude to implement the dynamic stabilization method for suppressing gross modes in tokamaks suggested in a recent paper [A. Thyagaraja, R. D. Hazeltine, and A. Y. Aydemir, Phys. Fluids B 4, 2733 (1992)]. This method works by ``detuning'' the resonant layer by rapid current/shear fluctuations. Estimates made for the power source requirements both for small machines such as COMPASS and for larger machines like JET suggest that the method could be practically feasible. This ``jitter'' (i.e., dynamic) stabilization method could provide a useful form of active instability control to avoid both gross/disruptive and fine-scale/transportive instabilities, which may set severe operating/safety constraints in the reactor regime. The results are also capable, in principle, of throwing considerable light on the local properties of current generation and diffusion in tokamaks, which may be enhanced by turbulence, as has been suggested recently by several researchers.

  1. Design investigation of solar powered lasers for space applications

    Science.gov (United States)

    Taussig, R.; Bruzzone, C.; Quimby, D.; Nelson, L.; Christiansen, W.; Neice, S.; Cassady, P.; Pindroh, A.

    1979-01-01

    The feasibility of solar powered lasers for continuous operation in space power transmission was investigated. Laser power transmission in space over distances of 10 to 100 thousand kilometers appears possible. A variety of lasers was considered, including solar-powered GDLs and EDLs, and solar-pumped lasers. An indirect solar-pumped laser was investigated which uses a solar-heated black body cavity to pump the lasant. Efficiencies in the range of 10 to 20 percent are projected for these indirect optically pumped lasers.

  2. Application of YAG laser processing in underwater welding and cutting

    International Nuclear Information System (INIS)

    Ohwaki, Katsura; Morita, Ichiro; Kojima, Toshio; Sato, Shuichi

    2002-01-01

    The high-power YAG laser is a new fabrication tool. The laser torch is easy to combine with complex with complex mechanics because of beam delivery through optical fiber. A direct underwater laser welding technology has been developed and applied to the preservation, maintenance and removal of nuclear power plants. For subdividing or removing operations for retirement of plants, the laser cutting properties were confirmed to allow a maximum cutting thickness of 80 mm. For repairing inner surface of stainless steel tanks, an underwater laser welding system using a remote-controlled robot was developed and the high quality of underwater laser welding was confirmed. (author)

  3. Diagnostics systems developments and applications for laser fusion experiments

    International Nuclear Information System (INIS)

    Coleman, L.W.

    1977-01-01

    A variety of systems are required for adequate diagnostics of laser fusion experiments. Picosecond scale temporal measurements are typically made with ultrafast streak cameras. Visible and x-ray sensitive streak cameras with resolutions of 6 psec and 15 psec, respectively, and dynamic recording range in excess of 10 3 are in regular use on experiments at Livermore. The characteristics of these cameras and their applications to target experiment diagnostics are described. The development and testing of a prototype ultrafast framing system is discussed. Because of the need for ''real time'' data acquisition, analysis, and control systems, techniques for providing directly computer interfaced image data from streak and framing cameras and optical imaging systems are being developed. The status of these developments and the characteristics of the computer interfaced data and control systems on Argus and Shiva are summarized

  4. Laser anemometer signals: visibility characteristics and application to particle sizing.

    Science.gov (United States)

    Adrian, R J; Orloff, K L

    1977-03-01

    The signal visibility characteristics of a dual beam laser anemometer operated in a backscatter mode have been investigated both experimentally and analytically. The analysis is based on Mie's electromagnetic scattering theory for spherical particles and is exact within the limitations of the scattering theory. It is shown that the signal visibility is a function of the ratio of the particle diameter to the fringe spacing in a certain, restricted case; but more generally it also depends on the Mie scattering size parameter, refractive index, the illuminating beam polarization, and the size, shape, and location of the light collecting aperture. The character of backscatter signal visibility differs significantly from the forward scatter case, and it is concluded that backscatter measurements of particle diameters using the visibility sizing technique may not always be possible. Restrictions on the forward scatter application of the visibility sizing method are also discussed.

  5. Effect of laser pulse on alternative current arc discharge during laser-arc hybrid welding of magnesium alloy

    Science.gov (United States)

    Chen, Minghua; Xin, Lijun; Zhou, Qi; He, Lijia; Wu, Fufa

    2018-01-01

    The coupling effect between a laser and arc plasma was studied in situations in which the laser acts at the positive and negative waveforms of the arc discharge during the laser-arc hybrid welding of magnesium alloy. Using the methods of direct observation, high speed imaging, and spectral analysis, the surface status of weld seams, weld penetration depths, plasma behavior, and spectral characteristics of welding plasma were investigated, respectively. Results show that, as compared with the laser pulse acting at the negative waveform of the arc plasma discharge, a better weld seam formation can be achieved when the laser pulse acts at the positive waveform of the arc discharge. At the same time, the radiation intensity of Mg atoms in the arc plasma increases significantly. However, the weld penetration depth is weaker. The findings show that when the laser pulse is acting at the negative waveform of the arc plasma discharge, the position of the arc plasma discharge on the workpiece can be restrained by the laser action point, which improves the energy density of the welding arc.

  6. The Newest Laser Processing

    International Nuclear Information System (INIS)

    Lee, Baek Yeon

    2007-01-01

    This book mentions laser processing with laser principle, laser history, laser beam property, laser kinds, foundation of laser processing such as laser oscillation, characteristic of laser processing, laser for processing and its characteristic, processing of laser hole including conception of processing of laser hole and each material, and hole processing of metal material, cut of laser, reality of cut, laser welding, laser surface hardening, application case of special processing and safety measurement of laser.

  7. Laser Resonators and Beam Propagation Fundamentals, Advanced Concepts and Applications

    CERN Document Server

    Hodgson, Norman

    2005-01-01

    Optical Resonators provides a detailed discussion of the properties of optical resonators for lasers from basic theory to recent research. In addition to describing the fundamental theories of resonators such as geometrical optics, diffraction, and polarisation the characteristics of all important resonator schemes and their calculation are presented. Experimental examples, practical problems and a collection of measurement techniques support the comprehensive treatment of the subject. Optical Resonators is the only book currently available that provides a comprehensive overview of the the subject. Combined with the structure of the text and the autonomous nature of the chapters this work will be as suitable for those new to the field as it will be invaluable to specialists conducting research. This second edition has been enlarged by new sections on Q-switching and resonators with internal phase/amplitude control. In addition, the whole book has been brought up-to-date.

  8. Spin-photo-currents generated by femtosecond laser pulses in a ferrimagnetic GdFeCo/Pt bilayer

    Science.gov (United States)

    Huisman, T. J.; Ciccarelli, C.; Tsukamoto, A.; Mikhaylovskiy, R. V.; Rasing, Th.; Kimel, A. V.

    2017-02-01

    Using THz emission spectroscopy, we detect spin-photo-currents from a ferrimagnetic amorphous alloy GdFeCo to an adjacent Pt capping layer. The currents are generated upon excitation of a GdFeCo/Pt heterostructure with femtosecond laser pulses. It is found that the polarization of the spin-polarized current is determined by magnetic sublattice sensitivity rather than the total magnetization, allowing for spin-polarized current generation when the net magnetization is zero.

  9. Ultra-Intense, High Spatio-Temporal Quality Petawatt-Class Laser System and Applications

    Directory of Open Access Journals (Sweden)

    Hirofumi Kan

    2013-03-01

    Full Text Available This paper reviews techniques for improving the temporal contrast and spatial beam quality in an ultra-intense laser system that is based on chirped-pulse amplification (CPA. We describe the design, performance, and characterization of our laser system, which has the potential for achieving a peak power of 600 TW. We also describe applications of the laser system in the relativistically dominant regime of laser-matter interactions and discuss a compact, high efficiency diode-pumped laser system.

  10. Characterization of high intensity Ni-like X-ray lasers and their application experiment

    Energy Technology Data Exchange (ETDEWEB)

    Tang, H.J.; Daido, H.; Suzuki, M. [Osaka Univ., Suita (Japan). Inst. of Laser Engineering; Japan Atomic Energy Research Inst., Kyoto (Japan). Advanced Photon Research Center; Yamagami, S.; Nagai, K.; Norimatsu, T.; Mima, K.; Yamanaka, T. [Osaka Univ., Suita (Japan). Inst. of Laser Engineering; Kato, Y.; Sasaki, A.; Hasegawa, N. [Japan Atomic Energy Research Inst., Kyoto (Japan). Advanced Photon Research Center; Wang, S.; Gu, Y.; Huang, G. [National Lab. on High Power Laser and Physics, Shanghai, SH (China); Carillon, A.; Ros, D.; Fourcade, P.; Jamelot, G. [Lab. de Spectroscopie Atomique et Ionique, Univ. Paris-Sud, Orsay (France); Joyeux, D.; Phalippou, D. [Lab. Charles Fabry, CNRS, Inst. d' Optique, Orsay (France); Murai, K. [Osaka National Research Inst., Ikeda, Osaka (Japan); Butzbach, R.; Uschmann, I.; Foerster, E. [IOQ, Friedrich-Schiller Univ., Jena (Germany); Namikawa, K.; Tai, R. [Tokyo Gakugei Univ., Koganei (Japan); Koike, F. [Kitasato Univ., Sagamihara, Kanagawa (Japan). School of Medicine; Takenaka, H. [NTT Advanced Technology, Musashino (Japan); Zhang, G. [Inst. of Applied Physics and Computational Mathematics, Beijing, BJ (China); Choi, I.W. [Korea Advanced Inst. of Science and Technology, Taejon (Korea)

    2001-07-01

    At the Institute of Laser Engineering, Osaka University, we have obtained Ni-like X-ray lasers of various atomic number elements, including many shorter wavelength Ni-like lasing lines around 5 nm. The saturated amplification of Ni-like Ag lasing line at the wavelength of 13.9 nm have been observed. Using these X-ray lasers, we are preparing the application experiments such as probing a laser-produced plasma with an X-ray laser interferometer. (orig.)

  11. Nanotechnology: current uses and future applications in the food industry.

    Science.gov (United States)

    Thiruvengadam, Muthu; Rajakumar, Govindasamy; Chung, Ill-Min

    2018-01-01

    Recent advances in nanoscience and nanotechnology intend new and innovative applications in the food industry. Nanotechnology exposed to be an efficient method in many fields, particularly the food industry and the area of functional foods. Though as is the circumstance with the growth of any novel food processing technology, food packaging material, or food ingredient, additional studies are needed to demonstrate the potential benefits of nanotechnologies and engineered nanomaterials designed for use in foods without adverse health effects. Nanoemulsions display numerous advantages over conventional emulsions due to the small droplets size they contain: high optical clarity, excellent physical constancy against gravitational partition and droplet accumulation, and improved bioavailability of encapsulated materials, which make them suitable for food applications. Nano-encapsulation is the most significant favorable technologies having the possibility to ensnare bioactive chemicals. This review highlights the applications of current nanotechnology research in food technology and agriculture, including nanoemulsion, nanocomposites, nanosensors, nano-encapsulation, food packaging, and propose future developments in the developing field of agrifood nanotechnology. Also, an overview of nanostructured materials, and their current applications and future perspectives in food science are also presented.

  12. Impedimetric biosensors for medical applications current progress and challenges

    CERN Document Server

    Rushworth, Jo V; Goode, Jack A; Pike, Douglas J; Ahmed, Asif; Millner, Paul

    2014-01-01

    In this monograph, the authors discuss the current progress in the medical application of impedimetric biosensors, along with the key challenges in the field. First, a general overview of biosensor development, structure and function is presented, followed by a detailed discussion of impedimetric biosensors and the principles of electrochemical impedance spectroscopy. Next, the current state-of-the art in terms of the science and technology underpinning impedance-based biosensors is reviewed in detail. The layer-by-layer construction of impedimetric sensors is described, including the design of electrodes, their nano-modification, transducer surface functionalization and the attachment of different bioreceptors. The current challenges of translating lab-based biosensor platforms into commercially-available devices that function with real patient samples at the POC are presented; this includes a consideration of systems integration, microfluidics and biosensor regeneration. The final section of this monograph ...

  13. Application of CO2 laser for electronic components soldering

    Science.gov (United States)

    Mascorro-Pantoja, J.; Soto-Bernal, J. J.; Nieto-Pérez, M.; Gonzalez-Mota, R.; Rosales-Candelas, I.

    2011-10-01

    Laser provides a high controllable and localized spot for soldering joint formation and this is a valuable tool in Sn/Pb Soldering process on electronic industry, in recent years, laser beam welding has become an emerging welding technique, the use of laser in welding area is a high efficiency method. A 60 Watts CO2 continuous laser was used on this study, during welding experimental results indicated the laser could significantly improve speed and weld quality. In this work, the welding interactions of CO2 laser with Sn/Pb wire have been investigated in details through varying the energy ratios of laser. And at the same time, the effect of distance from laser spot to material.

  14. INTERACTION OF LASER RADIATION WITH MATTER AND OTHER LASER APPLICATIONS: Changes in the emission properties of metal targets during pulse-periodic laser irradiation

    Science.gov (United States)

    Konov, Vitalii I.; Pimenov, S. M.; Prokhorov, A. M.; Chapliev, N. I.

    1988-02-01

    A scanning electron microscope was used with a pulse-periodic CO2 laser to discover the laws governing the correlation of the modified microrelief of metal surfaces, subjected to the action of multiple laser pulses, with the emission of charged particles and the luminescence of the irradiated zone. It was established that the influence of sorption and laser-induced desorption on the emission signals may be manifested differently depending on the regime of current generation in the "target-vacuum chamber" circuit.

  15. Semiconductor lasers stability, instability and chaos

    CERN Document Server

    Ohtsubo, Junji

    2017-01-01

    This book describes the fascinating recent advances made concerning the chaos, stability and instability of semiconductor lasers, and discusses their applications and future prospects in detail. It emphasizes the dynamics in semiconductor lasers by optical and electronic feedback, optical injection, and injection current modulation. Applications of semiconductor laser chaos, control and noise, and semiconductor lasers are also demonstrated. Semiconductor lasers with new structures, such as vertical-cavity surface-emitting lasers and broad-area semiconductor lasers, are intriguing and promising devices. Current topics include fast physical number generation using chaotic semiconductor lasers for secure communication, development of chaos, quantum-dot semiconductor lasers and quantum-cascade semiconductor lasers, and vertical-cavity surface-emitting lasers. This fourth edition has been significantly expanded to reflect the latest developments. The fundamental theory of laser chaos and the chaotic dynamics in se...

  16. Beat wave current drive with intense pulsed free-electron lasers

    International Nuclear Information System (INIS)

    Cohen, B.I.; Cohen, R.H.; Logan, B.G.; McCay Nevins, W.; Smith, G.R.; Kluge, A.V.; Kritz, A.H.

    1988-01-01

    High power free-electron lasers make possible new methods for driving current in toroidal devices with electromagnetic waves. Earlier considerations of beat wave current drive are applied to a hot magnetized plasma and an arbitrary beat wave. Here the beating of two electromagnetic waves resonantly excites a low frequency beat wave that accelerates and heats electrons and leads to a current. The absolute current drive efficiency depends non-linearly on the two pump wave intensities and is constrained by the Manley-Rowe relations. Accessibility at high plasma densities is not a difficulty, but a degree of frequency tunability of the wave sources is required. Particle simulations indicate that there is a good coupling to an electron velocity tail for a Langmuir beat wave with a phase velocity 1.5 to 3 times (T e /m e ) 1/2 , so that all of the high frequency wave source is absorbed and the beat wave damps completely on the electrons. A novel diagnostic, based on an analytical solution for the linearized Fokker-Planck equation describing electron scattering and slowing down, is added to the particle code. This permits the computation of the current drive efficiency, including both the non-linear beat wave coupling and the collisional relaxation of the electron distribution. A realistic scenario for a beat wave current drive experiment in the Livermore Microwave Tokamak Experiment is calculated using the TORAY toroidal ray tracing code, and the scaling to an engineering test reactor plasma is described. (author). 23 refs, 8 figs

  17. Monolithic Highly Stable Yb-Doped Femtosecond Fiber Lasers for Applications in Practical Biophotonics

    DEFF Research Database (Denmark)

    Liu, Xiaomin; Lægsgaard, Jesper; Turchinovich, Dmitry

    2012-01-01

    Operational and environmental stability of ultrafast laser systems is critical for their applications in practical biophotonics. Mode-locked fiber lasers show great promise in applications such as supercontinuum sources or multiphoton microscopy systems. Recently, substantial progress has been made...... in the development of all-fiber nonlinear-optical laser control schemes, which resulted in the demonstration of highly stable monolithic, i.e., not containing any free-space elements, lasers with direct fiber-end delivery of femtosecond pulses. This paper provides an overview of the progress in the development...

  18. 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 applicationsLaser 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...

  19. Note: Fast compact laser shutter using a direct current motor and three-dimensional printing

    Science.gov (United States)

    Zhang, Grace H.; Braverman, Boris; Kawasaki, Akio; Vuletić, Vladan

    2015-12-01

    We present a mechanical laser shutter design that utilizes a direct current electric motor to rotate a blade which blocks and unblocks a light beam. The blade and the main body of the shutter are modeled with computer aided design (CAD) and are produced by 3D printing. Rubber flaps are used to limit the blade's range of motion, reducing vibrations and preventing undesirable blade oscillations. At its nominal operating voltage, the shutter achieves a switching speed of (1.22 ± 0.02) m/s with 1 ms activation delay and 10 μs jitter in its timing performance. The shutter design is simple, easy to replicate, and highly reliable, showing no failure or degradation in performance over more than 108 cycles.

  20. High power multiple wavelength diode laser stack for DPSSL application without temperature control

    Science.gov (United States)

    Hou, Dong; Yin, Xia; Wang, Jingwei; Chen, Shi; Zhan, Yun; Li, Xiaoning; Fan, Yingmin; Liu, Xingsheng

    2018-02-01

    High power diode laser stack is widely used in pumping solid-state laser for years. Normally an integrated temperature control module is required for stabilizing the output power of solid-state laser, as the output power of the solid-state laser highly depends on the emission wavelength and the wavelength shift of diode lasers according to the temperature changes. However the temperature control module is inconvenient for this application, due to its large dimension, high electric power consumption and extra adding a complicated controlling system. Furthermore, it takes dozens of seconds to stabilize the output power when the laser system is turned on. In this work, a compact hard soldered high power conduction cooled diode laser stack with multiple wavelengths is developed for stabilizing the output power of solid-state laser in a certain temperature range. The stack consists of 5 laser bars with the pitch of 0.43mm. The peak output power of each bar in the diode laser stack reaches as much as 557W and the combined lasing wavelength spectrum profile spans 15nm. The solidstate laser, structured with multiple wavelength diode laser stacks, allows the ambient temperature change of 65°C without suddenly degrading the optical performance.

  1. Eddy Current Thermography: System Development and Its Application in NDT

    International Nuclear Information System (INIS)

    Nurliyana Shamimie Rusli; Ilham Mukriz Zainal Abidin; Sidek, H.A.A.

    2015-01-01

    Eddy Current Thermography (ECT) is an integrative technique which combines eddy current and thermographic NDT in order to provide an efficient method for defect detection. The technique is applicable to electrically conductive material and has the ability to detect surface and subsurface defect. ECT is a non-contact technique; has the ability to provide instantaneous response and high scanning speed that makes it reliable for defect detection and assessment. The technique combines electromagnetic excitation of the work-piece via a coil carrying current, heating of the material by induction and inspection by transient infrared thermography. In this paper, the development of ECT system is detailed, including coil design for global and local heating of samples, and optimisation of excitation parameters (frequency, power, heating duration etc). Results from 3D FEM simulation and experimental investigations are also presented to provide the overview of underlying phenomena and application of ECT. The work demonstrates the effectiveness of the developed ECT system and technique in defect detection and assessment. (author)

  2. Laser Speckle Contrast Imaging: theory, instrumentation and applications.

    Science.gov (United States)

    Senarathna, Janaka; Rege, Abhishek; Li, Nan; Thakor, Nitish V

    2013-01-01

    Laser Speckle Contrast Imaging (LSCI) is a wide field of view, non scanning optical technique for observing blood flow. Speckles are produced when coherent light scattered back from biological tissue is diffracted through the limiting aperture of focusing optics. Mobile scatterers cause the speckle pattern to blur; a model can be constructed by inversely relating the degree of blur, termed speckle contrast to the scatterer speed. In tissue, red blood cells are the main source of moving scatterers. Therefore, blood flow acts as a virtual contrast agent, outlining blood vessels. The spatial resolution (~10 μm) and temporal resolution (10 ms to 10 s) of LSCI can be tailored to the application. Restricted by the penetration depth of light, LSCI can only visualize superficial blood flow. Additionally, due to its non scanning nature, LSCI is unable to provide depth resolved images. The simple setup and non-dependence on exogenous contrast agents have made LSCI a popular tool for studying vascular structure and blood flow dynamics. We discuss the theory and practice of LSCI and critically analyze its merit in major areas of application such as retinal imaging, imaging of skin perfusion as well as imaging of neurophysiology.

  3. Optical and laser spectroscopic diagnostics for energy applications

    Science.gov (United States)

    Tripathi, Markandey Mani

    The continuing need for greater energy security and energy independence has motivated researchers to develop new energy technologies for better energy resource management and efficient energy usage. The focus of this dissertation is the development of optical (spectroscopic) sensing methodologies for various fuels, and energy applications. A fiber-optic NIR sensing methodology was developed for predicting water content in bio-oil. The feasibility of using the designed near infrared (NIR) system for estimating water content in bio-oil was tested by applying multivariate analysis to NIR spectral data. The calibration results demonstrated that the spectral information can successfully predict the bio-oil water content (from 16% to 36%). The effect of ultraviolet (UV) light on the chemical stability of bio-oil was studied by employing laser-induced fluorescence (LIF) spectroscopy. To simulate the UV light exposure, a laser in the UV region (325 nm) was employed for bio-oil excitation. The LIF, as a signature of chemical change, was recorded from bio-oil. From this study, it was concluded that phenols present in the bio-oil show chemical instability, when exposed to UV light. A laser-induced breakdown spectroscopy (LIBS)-based optical sensor was designed, developed, and tested for detection of four important trace impurities in rocket fuel (hydrogen). The sensor can simultaneously measure the concentrations of nitrogen, argon, oxygen, and helium in hydrogen from storage tanks and supply lines. The sensor had estimated lower detection limits of 80 ppm for nitrogen, 97 ppm for argon, 10 ppm for oxygen, and 25 ppm for helium. A chemiluminescence-based spectroscopic diagnostics were performed to measure equivalence ratios in methane-air premixed flames. A partial least-squares regression (PLS-R)-based multivariate sensing methodology was investigated. It was found that the equivalence ratios predicted with the PLS-R-based multivariate calibration model matched with the

  4. Space Solar Power Technology Demonstration for Lunar Polar Applications: Laser-Photovoltaic Wireless Power Transmission

    Science.gov (United States)

    Henley, M. W.; Fikes, J. C.; Howell, J.; Mankins, J. C.; Howell, Joe T. (Technical Monitor)

    2002-01-01

    Space Solar Power technology offers unique benefits for near-term NASA space science missions, which can mature this technology for other future applications. "Laser-Photo-Voltaic Wireless Power Transmission" (Laser-PV WPT) is a technology that uses a laser to beam power to a photovoltaic receiver, which converts the laser's light into electricity. Future Laser-PV WPT systems may beam power from Earth to satellites or large Space Solar Power satellites may beam power to Earth, perhaps supplementing terrestrial solar photo-voltaic receivers. In a near-term scientific mission to the moon, Laser-PV WPT can enable robotic operations in permanently shadowed lunar polar craters, which may contain ice. Ground-based technology demonstrations are proceeding, to mature the technology for this initial application, in the moon's polar regions.

  5. [Understanding the advantages and disadvantages of femtosecond laser comprehensive applications in ophthalmology].

    Science.gov (United States)

    Xie, Li-xin; Gao, Hua

    2013-04-01

    The femtosecond (FS) laser is a novel laser technology, and is approved clinical application by FDA in 2000. FS laser initially mainly used in corneal refractive surgery to replace the mechanical microkeratome. Since the accuracy and controllability of the FS laser is very high, it shows superiority in the field of corneal refractive surgery. And with the development of the relative hard and software, FS laser is began to used in other fields of ophthalmology, such as corneal transplants, cataract surgery, as well as assisted diagnosis et al., although still have some limitations, the preliminary clinical results have been shown a very good prospects in the ophthalmology fields. Therefore, we reviewed the alternative applications, challenges and limitations, research direction in the future of FS laser, so that provide a reference and revelations for the peers.

  6. Mineralized Collagen: Rationale, Current Status, and Clinical Applications

    Directory of Open Access Journals (Sweden)

    Zhi-Ye Qiu

    2015-07-01

    Full Text Available This paper presents a review of the rationale for the in vitro mineralization process, preparation methods, and clinical applications of mineralized collagen. The rationale for natural mineralized collagen and the related mineralization process has been investigated for decades. Based on the understanding of natural mineralized collagen and its formation process, many attempts have been made to prepare biomimetic materials that resemble natural mineralized collagen in both composition and structure. To date, a number of bone substitute materials have been developed based on the principles of mineralized collagen, and some of them have been commercialized and approved by regulatory agencies. The clinical outcomes of mineralized collagen are of significance to advance the evaluation and improvement of related medical device products. Some representative clinical cases have been reported, and there are more clinical applications and long-term follow-ups that currently being performed by many research groups.

  7. Current Applications and Future Prospects of Stem Cells in Dentistry.

    Science.gov (United States)

    Surendran, Sharmila; Sivamurthy, Gautham

    2015-01-01

    Stem cells are defined as clonogenic, unspecialized cells capable of both selt-renewal and multi-lineage differentiation, contributing to regenerating specific tissues. For years, restorative treatments have exploited the lifelong regenerative potential of dental pulp stem cells to give rise to tertiary dentine, which is therapeutically employed for direct and indirect pulp capping. Current applications of stem cells in endodontic research have revealed their potential to continue root development in necrotic immature teeth and transplanted/replanted teeth. Successful application of pulp revascularization is highlighted here with support of a clinical case report. This article also discusses the role of dental stem cells as a promising tool for regeneration of individual tissue types like dentine, pulp and even an entire functional tooth.

  8. Current overview on dental stem cells applications in regenerative dentistry.

    Science.gov (United States)

    Bansal, Ramta; Jain, Aditya

    2015-01-01

    Teeth are the most natural, noninvasive source of stem cells. Dental stem cells, which are easy, convenient, and affordable to collect, hold promise for a range of very potential therapeutic applications. We have reviewed the ever-growing literature on dental stem cells archived in Medline using the following key words: Regenerative dentistry, dental stem cells, dental stem cells banking, and stem cells from human exfoliated deciduous teeth. Relevant articles covering topics related to dental stem cells were shortlisted and the facts are compiled. The objective of this review article is to discuss the history of stem cells, different stem cells relevant for dentistry, their isolation approaches, collection, and preservation of dental stem cells along with the current status of dental and medical applications.

  9. Novel endoscopic application of a new flexible-fiber CO2 laser for esophageal mucosal ablation in a porcine model.

    Science.gov (United States)

    Anandasabapathy, S; Maru, D; Klumpp, S; Uthamanthil, R; Borne, A; Bhutani, M S

    2009-02-01

    The CO (2) laser is a surgical tool that is widely used because of its predictable penetration depth and minimal collateral damage due to efficient absorption of CO (2) laser energy by tissue water. Until recently, endoscopic use was limited by lack of an efficient, flexible delivery system. The aim of the current study was to evaluate the performance, efficacy, and safety of a novel, photonic band-gap CO (2) laser configured for esophageal mucosal ablation. This was an endoscopic experimental study in a porcine survival model. Initial evaluation was done on ex vivo tissue followed by endoscopic studies at 7-, 10-, 15-, and 20-W power and at 0-, 1-, 2-, 5-, and 10-mm distances, using continuous and pulsed currents, to determine optimal performance settings. In an IACUC-approved protocol, six pigs underwent circumferential ablation of the distal 6 cm of the esophagus at 10W continuous current. The animals were monitored for 2 or 4 weeks to evaluate delayed effects. Prior to euthanasia, the proximal esophagus was ablated to evaluate the homogeneity of ablation and depth of injury immediately after single and repeat ablation. The animals resumed normal diets within 24 hours and experienced no dysphagia or weight loss. Pathology at 2 and 4 weeks revealed complete re-epithelialization with minimal histologic injury. A single application of the laser produced complete transepithelial ablation of a mean of 83.3 % of the surface area (range 55 % - 100 %); depth of injury was to the muscularis mucosa in five pigs and to the superficial submucosa in one pig. With ablation, sloughing, and re-ablation, a mean of 95 % transepithelial ablation was achieved (range 80 % -100 %) with similar depth of injury. Using a novel, flexible CO (2) laser, homogeneous ablation was achieved with predictable penetration and minimal deep tissue injury. These results warrant further evaluation of the laser in Barrett's esophagus, as it may overcome the limitations of current technologies

  10. Analytical description of generation of the residual current density in the plasma produced by a few-cycle laser pulse

    Energy Technology Data Exchange (ETDEWEB)

    Silaev, A. A., E-mail: silaev@appl.sci-nnov.ru; Vvedenskii, N. V., E-mail: vved@appl.sci-nnov.ru [Institute of Applied Physics, Russian Academy of Sciences, Nizhny Novgorod 603950 (Russian Federation); University of Nizhny Novgorod, Nizhny Novgorod 603950 (Russian Federation)

    2015-05-15

    When a gas is ionized by a few-cycle laser pulse, some residual current density (RCD) of free electrons remains in the produced plasma after the passage of the laser pulse. This quasi-dc RCD is an initial impetus to plasma polarization and excitation of the plasma oscillations which can radiate terahertz (THz) waves. In this work, the analytical model for calculation of RCD excited by a few-cycle laser pulse is developed for the first time. The dependences of the RCD on the carrier-envelope phase (CEP), wavelength, duration, and intensity of the laser pulse are derived. It is shown that maximum RCD corresponding to optimal CEP increases with the laser pulse wavelength, which indicates the prospects of using mid-infrared few-cycle laser pulses in the schemes of generation of high-power THz pulses. Analytical formulas for optimal pulse intensity and maximum efficiency of excitation of the RCD are obtained. Basing on numerical solution of the 3D time-dependent Schrödinger equation for hydrogen atoms, RCD dependence on CEP is calculated in a wide range of wavelengths. High accuracy of analytical formulas is demonstrated at the laser pulse parameters which correspond to the tunneling regime of ionization.

  11. Effects of momentum transfer on sizing of current collectors for lithium-ion batteries during laser cutting

    Science.gov (United States)

    Lee, Dongkyoung; Mazumder, Jyotirmoy

    2018-02-01

    One of the challenges of the lithium-ion battery manufacturing process is the sizing of electrodes with good cut surface quality. Poor cut surface quality results in internal short circuits in the cells and significant heat generation. One of the solutions that may improve the cut quality with a high cutting speed is laser cutting due to its high energy concentration, fast processing time, high precision, small heat affected zone, flexible range of laser power and contact free process. In order to utilize the advantages of laser electrode cutting, understanding the physical phenomena for each material is crucial. Thus, this study focuses on the laser cutting of current collectors, such as pure copper and aluminum. A 3D self-consistent mathematical model for the laser cutting, including fluid flow, heat transfer, recoil pressure, multiple reflections, capillary and thermo-capillary forces, and phase changes, is presented and solved numerically. Simulation results for the laser cutting are analyzed in terms of penetration time, depth, width, and absorptivity, based on these selected laser parameters. In addition, melt pool flow, melt pool geometry and temperature distribution are investigated.

  12. Analysis of threshold current of uniaxially tensile stressed bulk Ge and Ge/SiGe quantum well lasers.

    Science.gov (United States)

    Jiang, Jialin; Sun, Junqiang; Gao, Jianfeng; Zhang, Ruiwen

    2017-10-30

    We propose and design uniaxially tensile stressed bulk Ge and Ge/SiGe quantum well lasers with the stress along direction. The micro-bridge structure is adapted for introducing uniaxial stress in Ge/SiGe quantum well. To enhance the fabrication tolerance, full-etched circular gratings with high reflectivity bandwidths of ~500 nm are deployed in laser cavities. We compare and analyze the density of state, the number of states between Γ- and L-points, the carrier injection efficiency, and the threshold current density for the uniaxially tensile stressed bulk Ge and Ge/SiGe quantum well lasers. Simulation results show that the threshold current density of the Ge/SiGe quantum well laser is much higher than that of the bulk Ge laser, even combined with high uniaxial tensile stress owing to the larger number of states between Γ- and L- points and extremely low carrier injection efficiency. Electrical transport simulation reveals that the reduced effective mass of the hole and the small conduction band offset cause the low carrier injection efficiency of the Ge/SiGe quantum well laser. Our theoretical results imply that unlike III-V material, uniaxially tensile stressed bulk Ge outperforms a Ge/SiGe quantum well with the same strain level and is a promising approach for Si-compatible light sources.

  13. Complex photonics: Dynamics and applications of delay-coupled semiconductors lasers

    OpenAIRE

    Soriano, Miguel C.; Garcia-Ojalvo, Jordi; Mirasso, Claudio R.; Fischer, Ingo

    2013-01-01

    Complex phenomena in photonics, in particular, dynamical properties of semiconductor lasers due to delayed coupling, are reviewed. Although considered a nuisance for a long time, these phenomena now open interesting perspectives. Semiconductor laser systems represent excellent test beds for the study of nonlinear delay-coupled systems, which are of fundamental relevance in various areas. At the same time delay-coupled lasers provide opportunities for photonic applications. In this review an i...

  14. The future of diode pumped solid state lasers and their applicability to the automotive industry

    Science.gov (United States)

    Solarz, R.; Beach, R.; Hackel, L.

    1994-03-01

    The largest commercial application of high power lasers is for cutting and welding. Their ability to increase productivity by introducing processing flexibility and integrated automation into the fabrication process is well demonstrated. This paper addresses the potential importance of recent developments in laser technology to further impact their use within the automotive industry. The laser technology we will concentrate upon is diode laser technology and diode-pumped solid-state laser technology. We will review present device performance and cost and make projections for the future in these areas. Semiconductor laser arrays have matured dramatically over the last several years. They are lasers of unparalleled efficiency (greater than 50%), reliability (greater than 10,000 hours of continuous operation), and offer the potential of dramatic cost reductions (less than a dollar per watt). They can be used directly in many applications or can be used to pump solid-state lasers. When used as solid-state laser pump arrays, they simultaneously improve overall laser efficiency, reduce size, and improve reliability.

  15. A computer controlled signal preprocessor for laser fringe anemometer applications

    Science.gov (United States)

    Oberle, Lawrence G.

    1987-01-01

    The operation of most commercially available laser fringe anemometer (LFA) counter-processors assumes that adjustments are made to the signal processing independent of the computer used for reducing the data acquired. Not only does the researcher desire a record of these parameters attached to the data acquired, but changes in flow conditions generally require that these settings be changed to improve data quality. Because of this limitation, on-line modification of the data acquisition parameters can be difficult and time consuming. A computer-controlled signal preprocessor has been developed which makes possible this optimization of the photomultiplier signal as a normal part of the data acquisition process. It allows computer control of the filter selection, signal gain, and photo-multiplier voltage. The raw signal from the photomultiplier tube is input to the preprocessor which, under the control of a digital computer, filters the signal and amplifies it to an acceptable level. The counter-processor used at Lewis Research Center generates the particle interarrival times, as well as the time-of-flight of the particle through the probe volume. The signal preprocessor allows computer control of the acquisition of these data.Through the preprocessor, the computer also can control the hand shaking signals for the interface between itself and the counter-processor. Finally, the signal preprocessor splits the pedestal from the signal before filtering, and monitors the photo-multiplier dc current, sends a signal proportional to this current to the computer through an analog to digital converter, and provides an alarm if the current exceeds a predefined maximum. Complete drawings and explanations are provided in the text as well as a sample interface program for use with the data acquisition software.

  16. Industrial fiber beam delivery system for ultrafast lasers: applications and recent advances

    Science.gov (United States)

    Eilzer, Sebastian; Funck, Max C.; Wedel, Björn

    2016-03-01

    Fiber based laser beam delivery is the method of choice for high power laser applications whenever great flexibility is required. For cw-lasers fiber beam delivery has long been established but has recently also become available for ultrafast lasers. Using micro-structured hollow core fibers that guide the laser beam mostly inside a hollow core, nonlinear effects and catastrophic damage that arise in conventional glass fibers can be avoided. Today, ultrafast pulses with several 100 μJ and hundreds of MW can be transmitted in quasi single mode fashion. In addition, the technology opens new possibilities for beam delivery systems as the pulse propagation inside the fiber can be altered on purpose. For example to shorten the pulse duration of picosecond lasers down into the femtosecond regime. We present a modular fiber beam delivery system for micromachining applications with industrial pico- and femtosecond lasers that is flexibly integrated into existing applications. Micro-structured hollow core fibers inside the sealed laser light cable efficiently guide high-power laser pulses over distances of several meters with excellent beam quality, while power, pulse duration and polarization are maintained. Robust and stable beam transport during dynamic operation as in robot or gantry systems will be discussed together with optional pulse compression.

  17. The use of lasers in dentistry: principles of operation and clinical applications.

    Science.gov (United States)

    Stabholz, Adam; Zeltser, Rephael; Sela, Mordechai; Peretz, Benjamin; Moshonov, Joshua; Ziskind, Daniel; Stabholz, Ayala

    2003-12-01

    This article describes the principles of laser operation and the clinical application of laser technology in the different fields of dentistry. It discusses the use of the Er:YAG laser in restorative dentistry, pediatric dentistry, and periodontics, as well as the introduction of a new side-firing spiral tip for efficient cleaning of the root canal system by means of lateral laser irradiation. Although the Er:YAG laser is used mostly on enamel and dentin, the gingival depigmentation procedure using this laser also is described. Clinical applications of the CO2 and diode lasers on soft tissues, particularly in the fields of oral and maxillofacial surgery and perodontics, are explained. Because teeth whitening for esthetic reasons has gained increasing popularity in dentistry, the application of diode lasers for this purpose is discussed. All the dental laser procedures described in this article are conducted at the Hebrew University-Hadassah School of Dental Medicine and are further investigated in various clinical research projects.

  18. Laser resection of lung tissue: heat accumulation from adjacent laser application and how to cool it down.

    Science.gov (United States)

    Kirschbaum, Andreas; Rexin, Peter; Pehl, Anika; Bartsch, Detlef; Quint, Karl

    2014-06-01

    Heat accumulation might induce thermal damage of the surrounding lung tissue, especially when multiple lesions are resected in one session. The present study aimed to investigate whether heat accumulates in the immediate vicinity of the resection surface and leads to thermal damage of the lung parenchyma, and what is the most effective cooling strategy in this situation. In normothermic perfused paracardial swine lobes (n = 6), four punctiform laser lesions forming a square were created. Each lesion was lasered at a power of 100 W for 5 seconds. Two test conditions with square sides of either 1.0 or 0.5 cm were compared. Temperatures were recorded immediately after completing the laser procedure in the square center and in the corners using a thermal camera and continued during the cooling process at 10-second intervals until normothermia (37°C). We examined two cooling methods: rinsing with ice-cold (4°C) Ringer solution during the laser procedure (group B, n = 6) or submerging the lung in ice-cold water for 5 seconds immediately after laser application (group C, n = 6). In the control group A (n = 6), there was no cooling. In the 0.5 cm squares, mean temperature in the center immediately after laser application was 103.17 ± 8.56°C, significantly higher than in the corners (76.39 ± 2.87°C, p Laser application to the lung parenchyma causes considerable heat accumulation in closely related lesions. To prevent such cell damage, a distance of at least 1.0 cm between laser targets should be maintained. If no topical cooling method applied, sufficient time for spontaneous tissue cooling before additional laser application should be provided. The most effective cooling strategy against heat accumulation is submerging in ice-cold water for at least 5 seconds. Georg Thieme Verlag KG Stuttgart · New York.

  19. The Development of Low Threshold Laser Arrays and Their Applications in Parallel Optical Datalinks

    Science.gov (United States)

    Zhao, Hanmin

    We present the analytical and experimental study for the development of ultra-low threshold InGaAs/GaAs/AlGaAs quantum well semiconductor lasers and laser arrays grown on non planar substrates by MOCVD. This study has resulted in the demonstration of some of the lowest threshold currents and current densities yet reported as well as the demonstration of multichannel optical datalinks working at 1Gbit/sec/channel. The gain properties of the InGaAs/GaAs strained quantum wells and the lasing properties of InGaAs/GaAs lasers were theoretically analysed. Using MOCVD growth technique, the growth condition for InGaAs/GaAs quantum wells and InGaAs/GaAs broad area lasers were optimized. InGaAs/GaAs broad area laser threshold current density as low as 56 A/cm^{-2} were obtained. The growth and doping properties of InGaAs/GaAs quantum wells and AlGaAs bulk layer on non planar substrates were studied and the unique properties we learned from the above study were used to design and fabricate a new buried heterostructure InGaAs/GaAs laser for low threshold and high efficiency operation. Record low threshold current of 0.5 mA and 0.6 mA were obtained for as cleaved DQW lasers and SQW lasers respectively. HR coated SQW laser threshold currents as low as 0.15 mA were obtained which is the lowest reported threshold current in a diode laser. This new technique produces high yield and high laser uniformity because of the simple growth and processing procedures involved. Highly uniform InGaAs/GaAs SQW and DQW laser arrays with sub-milliampere threshold currents were obtained. Using the above low threshold lasers, a unique three terminal laser structure that is suitable for high speed, high efficiency, large signal, digital modulation was investigated. Three terminal laser arrays were used in a wide bandwidth parallel optical datalink system. High data transfer rate (1GBit/sec/channel) and low bit error rate (BER) ({<}10^{-13}) with large phase margin were obtained. This parallel

  20. Improvement of the experimental content in Laser Principle and its Application

    Science.gov (United States)

    Niu, Chun-hui; Lang, Xiao-ping; Lv, Yong; Meng, Hao

    2017-08-01

    Experimental teaching content of Laser Principle and Its Application is proposed to improve from experimental teaching devices and experimental guide book. At first, a experimental system of laser-diode-pumped solid-state laser is designed and manufactured. Separate optical components are adopted in the designed experimental system and students can put these optical components on every place and their ability to establish and adjust optical path can be enhanced. Moreover, experimental education outline of Laser Principle and Its Application is revised and improved. At last, experimental guide book for the designed and manufactured experimental device is written. The experimental teaching innovation will improve experimental teaching effect and quality of Laser Principle and Its Application.

  1. Coagulative and ablative characteristics of a novel diode laser system (1470nm) for endonasal applications

    Science.gov (United States)

    Betz, C. S.; Havel, M.; Janda, P.; Leunig, A.; Sroka, R.

    2008-02-01

    Introduction: Being practical, efficient and inexpensive, fibre guided diode laser systems are preferable over others for endonasal applications. A new medical 1470 nm diode laser system is expected to offer good ablative and coagulative tissue effects. Methods: The new 1470 nm diode laser system was compared to a conventional 940 nm system with regards to laser tissue effects (ablation, coagulation, carbonization zones) in an ex vivo setup using fresh liver and muscle tissue. The laser fibres were fixed to a computer controlled stepper motor, and the light was applied using comparable power settings and a reproducible procedure under constant conditions. Clinical efficacy and postoperative morbidity was evaluated in two groups of 10 patients undergoing laser coagulation therapy of hyperplastic nasal turbinates. Results: In the experimental setup, the 1470 nm laser diode system proved to be more efficient in inducing tissue effects with an energy factor of 2-3 for highly perfused hepatic tissue to 30 for muscular tissue. In the clinical case series, the higher efficacy of the 1470 nm diode laser system led to reduced energy settings as compared to the conventional system with comparable clinical results. Postoperative crusting was less pronounced in the 1470 nm laser group. Conclusion: The 1470 nm diode laser system offers a highly efficient alternative to conventional diode laser systems for the coagulation of hyperplastic nasal turbinates. According to the experimental results it can be furthermore expected that it disposes of an excellent surgical potential with regards to its cutting abilities.

  2. Current trends and progress in clinical applications of oocyte cryopreservation

    Science.gov (United States)

    Cil, Aylin P.; Seli, Emre

    2013-01-01

    Purpose of review To delineate the current trends in the clinical application of oocyte cryopreservation. Recent findings Although the first live birth from oocyte cryopreservation was reported approximately three decades ago, significant improvement in the clinical application of oocyte cryopreservation took place only over the past decade. On the basis of the available evidence suggesting that success rates with donor oocyte vitrification are similar to that of IVF with fresh donor oocytes, the American Society of Reproductive Medicine has recently stated that oocyte cryopreservation should no longer be considered experimental for medical indications, outlying elective oocyte cryopreservation. Meanwhile, a few surveys on the attitudes toward oocyte cryopreservation revealed that elective use for the postponement of fertility is currently the most common indication for oocyte cryopreservation. Most recently, a randomized controlled trial revealed important evidence on the safety of nondonor oocyte cryopreservation, and confirmed that the clinical success of vitrification is comparable to that of IVF with fresh oocytes. Summary The evidence suggesting similar IVF success rates with both donor and nondonor cryopreserved oocytes compared with fresh oocytes will increase the utilization of elective oocyte cryopreservation. Appropriate counseling of women for oocyte cryopreservation requires the establishment of age-based clinical success rates with cryopreserved oocytes for various indications. PMID:23562954

  3. On-chip integrated lasers for biophotonic applications

    DEFF Research Database (Denmark)

    Mappes, Timo; Wienhold, Tobias; Bog, Uwe

    Meeting the need of biomedical users, we develop disposable Lab-on-a-Chip systems based on commercially available polymers. We are combining passive microfluidics with active optical elements on-chip by integrating multiple solid-state and liquid-core lasers. While covering a wide range of laser...... emission wavelengths, the chips have the size of microscope cover slips and use optical and fluidic interconnects only. Here, we present our latest realizations of integrated optofluidic lasers using whispering gallery mode or distributed feedback laser cavities....

  4. Basics of Lasers: History, Physics, and Clinical Applications.

    Science.gov (United States)

    Franck, Philipp; Henderson, Peter W; Rothaus, Kenneth O

    2016-07-01

    Lasers are increasingly used by plastic surgeons to address issues such as wrinkles and textural changes, skin laxity, hyperpigmentation, vascularity, and excess fat accumulation. A fundamental understanding of the underlying science and physics of laser technology is important for the safe and efficacious use of laser in medical settings. The purpose of this article was to give clinicians with limited exposure to lasers a basic understanding of the underlying science. In that manner, they can confidently make appropriate decisions as to the best device to use on a patient (or the best device to purchase for a practice). Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Application of a laser-heater for advanced guiding of PetaWatt laser pulses in capillary plasmas

    Science.gov (United States)

    Gonsalves, Anthony; Daniels, Joost; Benedetti, Carlo; Mao, Hann-Shin; Nakamura, Kei; Pieronek, Christopher; Schroeder, Carl; Steinke, Sven; Leemans, Wim

    2017-10-01

    Laser-plasma accelerators (LPAs) form an attractive scheme for developing compact accelerators, due to their high acceleration gradients. In the push to higher electron beam energies, one of the main challenges is to increase the dephasing length Ld over which energy can be transferred to the electrons, while keeping the laser confined to provide the required accelerating fields. Currently, the highest energy electron beams from an LPA have been achieved by using pre-formed density channels from capillary discharge plasmas. Confinement of laser pulses with higher order mode content required higher density than optimum for reaching higher energies. Improved laser confinement at lower density, extending Ld, has been proposed through use of a ns-scale heater pulse before the ultrashort, high-powered pulse arrives. Here, we present experimental results of applying this technique to channels of up to 20 cm in length to enhance guiding of PetaWatt pulses from the BELLA laser, including electron and laser properties from the accelerator. This work was supported by the Director, Office of Science, Office of High Energy Physics, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

  6. Current and Perspective Applications of Dense Plasma Focus Devices

    Science.gov (United States)

    Gribkov, V. A.

    2008-04-01

    Dense Plasma Focus (DPF) devices' applications, which are intended to support the main-stream large-scale nuclear fusion programs (NFP) from one side (both in fundamental problems of Dense Magnetized Plasma physics and in its engineering issues) as well as elaborated for an immediate use in a number of fields from the other one, are described. In the first direction such problems as self-generated magnetic fields, implosion stability of plasma shells having a high aspect ratio, etc. are important for the Inertial Confinement Fusion (ICF) programs (e.g. as NIF), whereas different problems of current disruption phenomenon, plasma turbulence, mechanisms of generation of fast particles and neutrons in magnetized plasmas are of great interest for the large devices of the Magnetic Plasma Confinement—MPC (e.g. as ITER). In a sphere of the engineering problems of NFP it is shown that in particular the radiation material sciences have DPF as a very efficient tool for radiation tests of prospect materials and for improvement of their characteristics. In the field of broad-band current applications some results obtained in the fields of radiation material sciences, radiobiology, nuclear medicine, express Neutron Activation Analysis (including a single-shot interrogation of hidden illegal objects), dynamic non-destructive quality control, X-Ray microlithography and micromachining, and micro-radiography are presented. As the examples of the potential future applications it is proposed to use DPF as a powerful high-flux neutron source to generate very powerful pulses of neutrons in the nanosecond (ns) range of its duration for innovative experiments in nuclear physics, for the goals of radiation treatment of malignant tumors, for neutron tests of materials of the first wall, blankets and NFP device's constructions (with fluences up to 1 dpa per a year term), and ns pulses of fast electrons, neutrons and hard X-Rays for brachytherapy.

  7. Laser beam shaping optical system design methods and their application in edge-emitting semiconductor laser-based LIDAR systems

    Science.gov (United States)

    Serkan, Mert

    LIDAR (Light Detection And Ranging) systems are employed for numerous applications such as remote sensing, military applications, optical data storage, display technology, and material processing. Furthermore, they are superior to other active remote sensing tools such as RADAR systems, considering their higher accuracy and more precise resolution due to their much shorter wavelengths and narrower beamwidth. Several types of lasers can be utilized as the radiation source of several LIDAR systems. Semiconductor laser-based LIDAR systems have several advantages such as low cost, compactness, broad range of wavelengths, and high PRFs (Pulse Repetition Frequency). However, semiconductor lasers have different origins and angles of divergence in the two transverse directions, resulting in the inherent astigmatism and elliptical beam shape. Specifically, elliptical beam shape is not desirable for several laser-based applications including LIDAR systems specifically designed to operate in the far-field region. In this dissertation, two mirror-based and two lens-based beam shapers are designed to circularize, collimate, and expand an edge-emitting semiconductor laser beam to a desired beam diameter for possible application in LIDAR systems. Additionally, most laser beams including semiconductor laser beams have Gaussian irradiance distribution. For applications that require uniform illumination of an extended target area, Gaussian irradiance distribution is undesirable. Therefore, a specific beam shaper is designed to transform the irradiance distribution from Gaussian to uniform in addition to circularizing, collimating, and expanding the semiconductor laser beam. For the design of beam shapers, aperture sizes of the surfaces are preset for desired power transmission and allowed diffraction level, surface parameters of the optical components and the distances between these surfaces are determined. Design equations specific to these beam shaping optical systems are

  8. Processing and Application of ICESat Large Footprint Full Waveform Laser Range Data

    NARCIS (Netherlands)

    Duong, V.H.

    2010-01-01

    In the last two decades, laser scanning systems made the transition from scientific research to the commercial market. Laser scanning has a large variety of applications such as digital elevation models, forest inventory and man-made object reconstruction, and became the most required input data for

  9. High repetition rate pulsed gas lasers and their applications in chemistry and isotope separation

    International Nuclear Information System (INIS)

    Barahov, V.Y.

    1983-01-01

    Presented in this paper are the results of experimental studies of pulsed high repetition rate XeCl, CO 2 , NH 3 , and CF 4 lasers with a closed gas cycle. Some applications of these lasers in chemistry and isotope separation are discussed

  10. Laser applications to chemical and environmental analysis: introduction to the feature issue.

    Science.gov (United States)

    Allen, M G; Shaw, R W; Sick, V

    1999-03-20

    This issue of Applied Optics features 16 papers describing chemical and environmental measurements made possible by lasers. Many of these contributions were presented at the Optical Society of America Topical Meeting on Laser Applications to Chemical and Environmental Analysis, held in Orlando, Florida, 9-11 March 1998.

  11. Optical systems for high-power laser applications: principles and design aspects

    NARCIS (Netherlands)

    Beckmann, L.H.J.F.; Ehrlichmann, D.

    1995-01-01

    Starting from the optical properties of laser beams, the requirements of optical systems for manipulating laser radiation in industrial applications are derived. The relevant parameters, relations to the diffraction limit and the state-of-the-art design techniques are discussed. The three important

  12. Laser fusion program overview

    International Nuclear Information System (INIS)

    Emmett, J.L.

    1977-01-01

    This program is structured to proceed through a series of well defined fusion milestones to proof of the scientific feasibility, of laser fusion with the Shiva Nova system. Concurrently, those key technical areas, such as advanced lasers, which are required to progress beyond proof of feasibility, are being studied. We have identified and quantified the opportunities and key technical issues in military applications, such as weapons effects simulations, and in civilian applications, such as central-station electric power production. We summarize the current status and future plans for the laser fusion program at LLL, emphasizing the civilian applications of laser fusion

  13. High current pulsed linear ion accelerators for inertial fusion applications

    International Nuclear Information System (INIS)

    Humphries, S. Jr.; Yonas, G.; Poukey, J.W.

    1978-01-01

    Pulsed ion beams have a number of advantages for use as inertial fusion drivers. Among these are classical interaction with targets and good efficiency of production. As has been pointed out by members of the accelerator community, multistage accelerators are attractive in this context because of lower current requirements, low power flow per energy conversion stage and low beam divergence at higher ion energies. On the other hand, current transport limits in conventional accelerators constrain them to the use of heavy ions at energies much higher than those needed to meet the divergence requirements, resulting in large, costly systems. We have studied methods of neutralizing ion beams with electrons within the accelerator volume to achieve higher currents. The aim is to arrive at an inexpensive accelerator that can advantageously use existing pulsed voltage technology while being conservative enough to achieve a high repetition rate. Typical output parameters for reactor applications would be an 0 + beam of 30 kA at 300 MeV. We will describe reactor scaling studies and the physics of neutralized linear accelerators using magnetic fields to control the electron dynamics. Recent results are discussed from PULSELAC, a five stage multikiloampere device being tested at Sandia Laboratories

  14. APPLICATION OF PULSE-PERIODICAL MODE FOR IMPROVEMENT OF LASER TREATMENT EFFICIENCY

    Directory of Open Access Journals (Sweden)

    V. V. Apollonov

    2014-01-01

    Full Text Available The purpose of the paper is to estimate an application of pulse-periodical mode for improvement of laser treatment efficiency. Laser technologies have been widely used in the processes of material treatment with the purpose to provide them the required surface properties and also for high accuracy cutting of sheet materials. Application of complex treatment is of great interest and especially when it is used for worn-out surfaces with formation of a coating by gas-flame laying of powder mixture of specific composition and subsequent laser fusion.Increase of laser unit capacity is very important task for higher efficiency of laser technology application in mechanical engineering. Nowadays technological processes using lasers with high average power (more than 100 W have been applying only sources that are working in two modes, namely: continuous and pulse- periodical (P-P with pulse repetition rate from some units to several hundred hertz and pulse duration within dozens to hundreds of microseconds and even within milliseconds. On the other hand, in some cases shielding effect of plasma cloud formed during laser alloying, cladding or welding reduces the efficiency of laser treatment up to 50 % depending on plasma composition and laser beam length. High frequency P-P laser systems with high average power working in mode of Q-factor modulation allow to realize principally other mechanism of irradiation interaction with materials that is an ablation. In this case it is possible to provide local energy release both in space and time.The performed analysis has revealed that P-P mode of laser operation for a majority of treatment processes is much better and more efficient from energetic point of view in comparison with the continuous mode. On the basis of the developments it is possible to make a conclusion that there is a possibility to create laser systems working in high frequency P-P mode with high average power above hundreds watt.

  15. REVIEW ARTICLE: Some recent developments in two-and three-dimensional laser forming for 'macro' and 'micro' applications

    Science.gov (United States)

    Dearden, G.; Edwardson, S. P.

    2003-07-01

    Laser forming (LF) is an emerging laser process with potential for use in line bending or spatial forming of metal components and in the precise adjustment of novel miniature on-board actuators. The process is achieved by introducing thermal stresses into a work-piece by controlled irradiation with a focused laser beam. Unlike mechanical forming, there is no spring-back effect. A number of mechanisms have been identified to explain the thermo-mechanical behaviour in LF, accounting for various part geometries, laser process conditions and the complex interaction of many thermal and mechanical factors. Although these interactions are not yet fully understood, with increased knowledge of the process (in terms of theoretical models and control strategies) and the continued development of adaptive and/or predictive LF systems, the process offers significant potential value to industry. This review describes a number of recent developments and new techniques in two-and three-dimensional LF, for both macro-and micro-scale applications, and gives suggestions on the current industrial promise of the process. Macro-scale applications include rapid prototyping in industries that have relied on using expensive stamping dies and presses for design evaluations, while micro-scale applications already include the precision alignment of components during product assembly.

  16. Reverse Current Characteristics of InP Gunn Diodes for W-Band Waveguide Applications.

    Science.gov (United States)

    Kim, Hyun-Seok; Heo, Jun-Woo; Chol, Seok-Gyu; Ko, Dong-Sik; Rhee, Jin-Koo

    2015-07-01

    InP is considered as the most promising material for millimeter-wave laser-diode applications owing to its superior noise performance and wide operating frequency range of 75-110 GHz. In this study, we demonstrate the fabrication of InP Gunn diodes with a current-limiting structure using rapid thermal annealing to modulate the potential height formed between an n-type InP active layer and a cathode contact. We also explore the reverse current characteristics of the InP Gunn diodes. Experimental results indicate a maximum anode current and an oscillation frequency of 200 mA and 93.53 GHz, respectively. The current-voltage characteristics are modeled by considering the Schottky and ohmic contacts, work function variations, negative differential resistance (NDR), and tunneling effect. Although no direct indication of the NDR is observed, the simulation results match the measured data well. The modeling results show that the NDR effect is always present but is masked because of electron emission across the shallow Schottky barrier.

  17. Laser-driven particle and photon beams and some applications

    International Nuclear Information System (INIS)

    Ledingham, K W D; Galster, W

    2010-01-01

    Outstanding progress has been made in high-power laser technology in the last 10 years with laser powers reaching petawatt (PW) values. At present, there are 15 PW lasers built or being built around the world and plans are afoot for new, even higher power, lasers reaching values of exawatt (EW) or even zetawatt (ZW) powers. Petawatt lasers generate electric fields of 10 12 V m -1 with a large fraction of the total pulse energy being converted to relativistic electrons with energies reaching in excess of 1 GeV. In turn these electrons result in the generation of beams of protons, heavy ions, neutrons and high-energy photons. These laser-driven particle beams have encouraged many to think of carrying out experiments normally associated with conventional nuclear accelerators and reactors. To this end a number of introductory articles have been written under a trial name 'Laser Nuclear Physics' (Ledingham and Norreys 1999 Contemp. Phys. 40 367, Ledingham et al 2002 Europhys. News. 33 120, Ledingham et al 2003 Science 300 1107, Takabe et al 2001 J. Plasma Fusion Res. 77 1094). However, even greater strides have been made in the last 3 or 4 years in laser technology and it is timely to reassess the potential of laser-driven particle and photon beams. It must be acknowledged right from the outset that to date laser-driven particle beams have yet to compete favourably with conventional nuclear accelerator-generated beams in any way and so this is not a paper comparing laser and conventional accelerators. However, occasionally throughout the paper as a reality check, it will be mentioned what conventional nuclear accelerators can do.

  18. Laser-driven particle and photon beams and some applications

    Energy Technology Data Exchange (ETDEWEB)

    Ledingham, K W D; Galster, W, E-mail: K.Ledingham@phys.strath.ac.u [SUPA, Department of Physics, University of Strathclyde, Glasgow G4 0NG (United Kingdom)

    2010-04-15

    Outstanding progress has been made in high-power laser technology in the last 10 years with laser powers reaching petawatt (PW) values. At present, there are 15 PW lasers built or being built around the world and plans are afoot for new, even higher power, lasers reaching values of exawatt (EW) or even zetawatt (ZW) powers. Petawatt lasers generate electric fields of 10{sup 12} V m{sup -1} with a large fraction of the total pulse energy being converted to relativistic electrons with energies reaching in excess of 1 GeV. In turn these electrons result in the generation of beams of protons, heavy ions, neutrons and high-energy photons. These laser-driven particle beams have encouraged many to think of carrying out experiments normally associated with conventional nuclear accelerators and reactors. To this end a number of introductory articles have been written under a trial name 'Laser Nuclear Physics' (Ledingham and Norreys 1999 Contemp. Phys. 40 367, Ledingham et al 2002 Europhys. News. 33 120, Ledingham et al 2003 Science 300 1107, Takabe et al 2001 J. Plasma Fusion Res. 77 1094). However, even greater strides have been made in the last 3 or 4 years in laser technology and it is timely to reassess the potential of laser-driven particle and photon beams. It must be acknowledged right from the outset that to date laser-driven particle beams have yet to compete favourably with conventional nuclear accelerator-generated beams in any way and so this is not a paper comparing laser and conventional accelerators. However, occasionally throughout the paper as a reality check, it will be mentioned what conventional nuclear accelerators can do.

  19. Laser mass spectrometry for DNA fingerprinting for forensic applications

    Energy Technology Data Exchange (ETDEWEB)

    Chen, C.H.; Tang, K.; Taranenko, N.I.; Allman, S.L.; Chang, L.Y.

    1994-12-31

    The application of DNA fingerprinting has become very broad in forensic analysis, patient identification, diagnostic medicine, and wildlife poaching, since every individual`s DNA structure is identical within all tissues of their body. DNA fingerprinting was initiated by the use of restriction fragment length polymorphisms (RFLP). In 1987, Nakamura et al. found that a variable number of tandem repeats (VNTR) often occurred in the alleles. The probability of different individuals having the same number of tandem repeats in several different alleles is very low. Thus, the identification of VNTR from genomic DNA became a very reliable method for identification of individuals. DNA fingerprinting is a reliable tool for forensic analysis. In DNA fingerprinting, knowledge of the sequence of tandem repeats and restriction endonuclease sites can provide the basis for identification. The major steps for conventional DNA fingerprinting include (1) specimen processing (2) amplification of selected DNA segments by PCR, and (3) gel electrophoresis to do the final DNA analysis. In this work we propose to use laser desorption mass spectrometry for fast DNA fingerprinting. The process and advantages are discussed.

  20. Laser direct written silicon nanowires for electronic and sensing applications

    Science.gov (United States)

    Nam, Woongsik

    Silicon nanowires are promising building blocks for high-performance electronics and chemical/biological sensing devices due to their ultra-small body and high surface-to-volume ratios. However, the lack of the ability to assemble and position nanowires in a highly controlled manner still remains an obstacle to fully exploiting the substantial potential of nanowires. Here we demonstrate a one-step method to synthesize intrinsic and doped silicon nanowires for device applications. Sub-diffraction limited nanowires as thin as 60 nm are synthesized using laser direct writing in combination with chemical vapor deposition, which has the advantages of in-situ doping, catalyst-free growth, and precise control of position, orientation, and length. The synthesized nanowires have been fabricated into field effect transistors (FETs) and FET sensors. The FET sensors are employed to detect the proton concentration (pH) of an aqueous solution and highly sensitive pH sensing is demonstrated. Both top- and back-gated silicon nanowire FETs are demonstrated and electrically characterized. In addition, modulation-doped nanowires are synthesized by changing dopant gases during the nanowire growth. The axial p-n junction nanowires are electrically characterized to demonstrate the diode behavior and the transition between dopant levels are measured using Kelvin probe force microscopy.

  1. Laser-capture microdissection: applications in routine molecular dermatopathology.

    Science.gov (United States)

    Yazdi, Amir S; Puchta, Ursula; Flaig, Michael J; Sander, Christian A

    2004-08-01

    Advances in molecular pathology with the introduction of the Southern blot technique and the polymerase chain reaction (PCR) have emerged as important tools, which are frequently used in routine dermato-histopathology. Applications for PCR-based diagnostics are particularly helpful for the determination of clonality in cutaneous lymphocytic infiltrates and for detection of infectious agents, such as herpes simplex virus (HSV), varicella zoster virus (VZV), Borrelia burgdorferi, Mycobacteria, Leishmania, and Treponema pallidum. As biopsies are always composed of different cells, the cells of interest are often only a minor population. As a consequence, their specific DNA is diluted by the majority of contaminating cells. Another problem is the time- and labor-intensive DNA extraction, because usually only formalin-fixed, paraffin-embedded tissue is available, which makes molecular diagnostics a time and labor consuming, and consequently a cost-intensive procedure. To overcome these shortcomings and to eventually shorten the time to generate a result, we introduce a laser-capture microdissection (LCM)-based method for the detection of infectious agents and clonality. Only the cells of interest for the particular indication are microdissected (e.g. epidermal cells for HSV and VZV and lymphocytes for clonality analysis) and subjected to PCR amplification. Due to an accelerated DNA-extraction procedure which generates DNA in 5 h (compared to 3-4 days using conventional DNA extraction), we are able to generate a result within one working day.

  2. Development and applications of X-ray lasers at LSAI/LIXAM

    International Nuclear Information System (INIS)

    Klisnick, Annie; Jamelot, Gerard; Ros, David; Carillon, Antoine; Jaegle, Pierre; Boussoukaya, Mustapha; Guilbaud, Olivier; Kuba, Jaroslav; Smith, Raymond; Lagron, Jean-Claude; Vanbostal, Laurent; Joyeux, Denis; Phalippou, Daniel; Sebban, Stephane; Touati, Alain; Du Penhoat, Marie Anne Herve; Ballester, F.; Petit, E.-J.; Rus, Bedrich; Mocek, Tomas

    2002-01-01

    We present an overview of our research activity achieved since the last X-ray laser Conference in Saint-Malo. Our research program involves the development of laser-pumped collisional X-ray lasers under different regimes of irradiation, and the use of these sources for applications. The work presented involves a number of French and international collaborations and was carried out at different pump laser facilities: LULI (Ecole Polytechnique), LOA (ESNTA) in France; Rutherford Laboratory in U.K; PALS in Czech Republic

  3. Nonlinear optics and solid-state lasers advanced concepts, tuning-fundamentals and applications

    CERN Document Server

    Yao, Jianquan

    2012-01-01

    This book covers the complete spectrum of nonlinear optics and all solid state lasers.The book integrates theory, calculations and practical design, technology, experimental schemes and applications. With the expansion and further development of Laser technology, the wavelength spectrum of Lasers had to be enlarged, even to be tunable which requires the use of nonlinear optical and Laser tunable technology. It systematically summarizes and integrates the analysis of international achievements within the last 20 years in this field. It will be helpful for university teachers, graduate students as well as engineers.

  4. Clinical applications of laser therapy on the dental practice

    Science.gov (United States)

    Pinheiro, Antonio L. B.

    2004-09-01

    Dental practice consists of a series of laboring procedures which demands the use of several types of equipment and materials. Usually patient"s fears brings additional burden to the Dentists. The use of Lasers for treating and diagnosis in Dentistry is quite new comparing to other medical areas. Initially Laser technology was used as an alternative method for treating dental caries in order to substitute the use of the drill. Lately surgical Lasers have shown themselves very useful for treating several pathologies and began to be used as a powerful tool on the treatment of several conditions affecting the maxillofacial complex and later on, the era of the use of Laser therapy began. The advent of the diode Lasers made possible the introduction of small units at the dental office and Laser therapy was used to improve healing and later included also caries diagnosis. This paper discuss the use of Laser therapy on Restorative Dentistry, Periodondology, Oral and Maxillofacial Surgery, Oral implantology and other. Clinical and laboratorial experience has demonstrated that Laser therapy does improve the healing of both mineralized and soft tissues, reduces pain and inflammation, and also reduces both cost and length of the dental treatment.

  5. Fabrication, operation, and applications of efficient dielectric waveguide lasers

    NARCIS (Netherlands)

    Pollnau, Markus; van Dalfsen, Koop; Bernhardi, Edward; Geskus, D.; Worhoff, Kerstin; de Ridder, R.M.; García Blanco, Sonia Maria

    This paper reviews our recent results on rare-earth-ion-doped integrated lasers. We have concentrated our efforts on crystalline potassium double tungstates and amorphous aluminum oxide. In the former material class we have demonstrated channel waveguide lasers based on Yb3+ doping, operating near 1

  6. Application of laser assisted cold spraying process for metal deposition

    CSIR Research Space (South Africa)

    Tlotleng, Monnamme

    2014-02-01

    Full Text Available Laser assisted cold spraying (LACS) process is a hybrid technique that uses laser and cold spray to deposit solid powders on metal substrates. For bonding to occur, the particle velocities must be supersonic which are achieved by entraining...

  7. On-chip integrated lasers for biophotonic applications

    DEFF Research Database (Denmark)

    Mappes, Timo; Wienhold, Tobias; Bog, Uwe

    Meeting the need of biomedical users, we develop disposable Lab-on-a-Chip systems based on commercially available polymers. We are combining passive microfluidics with active optical elements on-chip by integrating multiple solid-state and liquid-core lasers. While covering a wide range of laser ...

  8. Refresher Course on Lasers and Applications in Chemical Processes

    Indian Academy of Sciences (India)

    lasers, modes of laser, mode locking, Q-switching, nonlinear optical materials, electro- optic and magneto-optic materials. It will also include laboratory demonstration experi- ments in selected areas of fluorescence and pump-probe methods. Teachers who wish to participate in the Refresher Course should submit their brief.

  9. AlGaInN laser diode technology and systems for defence and security applications

    Science.gov (United States)

    Najda, Stephen P.; Perlin, Piotr; Suski, Tadek; Marona, Lujca; Boćkowski, Mike; Leszczyński, Mike; Wisniewski, Przemek; Czernecki, Robert; Kucharski, Robert; Targowski, Grzegorz; Watson, Scott; Kelly, Antony E.

    2015-10-01

    AlGaInN laser diodes is an emerging technology for defence and security applications such as underwater communications and sensing, atomic clocks and quantum information. The AlGaInN material system allows for laser diodes to be fabricated over a very wide range of wavelengths from u.v., ~380nm, to the visible ~530nm, by tuning the indium content of the laser GaInN quantum well. Thus AlGaInN laser diode technology is a key enabler for the development of new disruptive system level applications in displays, telecom, defence and other industries. Ridge waveguide laser diodes are fabricated to achieve single mode operation with optical powers up to 100mW with the 400-440nm wavelength range with high reliability. Visible free-space and underwater communication at frequencies up to 2.5GHz is reported using a directly modulated 422nm GaN laser diode. Low defectivity and highly uniform GaN substrates allow arrays and bars to be fabricated. High power operation operation of AlGaInN laser bars with up to 20 emitters have been demonstrated at optical powers up to 4W in a CS package with common contact configuration. An alternative package configuration for AlGaInN laser arrays allows for each individual laser to be individually addressable allowing complex free-space or optical fibre system integration with a very small form-factor.

  10. Application of laser resonance scattering to the study of high-temperature plasma-wall interaction

    International Nuclear Information System (INIS)

    Maeda, Mitsuo; Muraoka, Katsunori; Hamamoto, Makoto; Akazaki, Masanori; Miyazoe, Yasushi

    1981-01-01

    Studies on laser resonance scattering and its application to the study of high-temperature plasma-wall interaction are reviewed. The application of dye laser beam to resonant scattering method has been developed. This method is able to detect low density atoms. The fluorescent photon counts can be estimated for a two-level system and a three-level system. The S/N ratio, Which is in close connection with the detection limit, has been estimated. The doppler effect due to the thermal motion of atoms is taken into consideration. The calibration of the absolute number of atoms is necessary. Tunable coherent light is used as the light source for resonance scattering method. This is able to excite atoms strongly and to increase the detection efficiency. As dye lasers, a N 2 laser, a YAG laser, and a KrF excimer laser have been studied. In VUV region, rare gas or rare gas halide lasers can be used. The strong output power can be expected when the resonance lines of atoms meet the synchronizing region of the excimer laser. The resonance scattering method is applied to the detection of impurity metal atoms in plasma. The studies of laser systems for the detection of hydrogen atoms are also in progress. (Kato, T.)

  11. Effect of preionization, fluorine concentration, and current density on the discharge uniformity in F2 excimer laser gas mixtures

    NARCIS (Netherlands)

    Mathew, D.; Bastiaens, Hubertus M.J.; Boller, Klaus J.; Peters, P.J.M.

    2007-01-01

    The discharge homogeneity in F2-based excimer laser gas mixtures and its dependence on various key parameters, such as the degree of preionization, preionization delay time, F2 concentration and current density, is investigated in a small x-ray preionized discharge chamber. The spatial and temporal

  12. Terawatt Picosecond CO2 Laser Technology for High Energy Physics Applications

    International Nuclear Information System (INIS)

    Pogorelsky, I. V.

    1998-01-01

    Demonstration of ultra-high acceleration gradients in the SM LWFA experiments put a next objective for the laser accelerator development to achieve a low-emittance monochromatic acceleration over extended interaction distances. The emerging picosecond terawatt (ps-TW) CO 2 laser technology helps to meet this strategic goal. Among the considered examples are: the staged electron laser accelerator (STELLA) experiment, which is being conducted at the Brookhaven ATF, and the plasma-channeled LWFA. The long-wavelength and high average power capabilities of CO 2 lasers maybe utilized also for generation of intense x-ray and gamma radiation through Compton back-scattering of the laser beams off relativistic electrons. We discuss applications of ps-TW CO 2 lasers for a tentative γ-γ (or γ-lepton) collider and generation of polarized positron beams

  13. Spectrum Analyzer Application for the Proton Synchrotron Wall Current Monitors

    CERN Document Server

    Limpens, Rik

    The Proton Synchrotron (PS) is a key component in CERN's accelerator complex, where it usually accelerates either protons or heavy ions. The new acquisition system for the PS ring wall current monitors has been installed to be able to perform higher frequency measurements of a beam bunch. This is an important improvement, since the oscillating signals are related to losses of a beam bunch. The main goal of this project is to develop a LabVIEW application running on a Real-Time target to perform continuous and triggered spectral acquisition of a PS beam bunch and to provide a data visualization and analysis tool for the operators and users of the machine.

  14. Stem cells in orthopedics: current concepts and possible future applications.

    Science.gov (United States)

    Bagaria, Vaibhav; Patil, Nilesh; Sapre, Vikram; Chadda, Anshul; Singrakia, Manoj

    2006-04-01

    Stem cells are the cells that have the ability to divide for indefinite periods in culture and to give rise to specialized cells. Sources of these cells include embryo, umbilical cord and certain sites in adults such as the central nervous system [CNS] and bone marrow. Its use hold promise of wide spread applications particularly in areas of spinal cord injury, difficult non-unions, critical bone defects, spinal fusions, augmentation of ligament reconstructions, cartilage repair and degenerative disc disorders. This review article contains current information derived from Medline searches on the use in various orthopedic subspecialties. Some issues remain at the forefront of the controversy involving stem cell research - legislation, ethics and public opinion, cost and concentration methods. As is true with any new technology, the enthusiasm for this technology that has potential to influence virtually every orthopedic case management, must be balanced by subjecting it to stringent clinical and basic research investigations.

  15. Current evidence and applications of photodynamic therapy in dermatology

    Science.gov (United States)

    Wan, Marilyn T; Lin, Jennifer Y

    2014-01-01

    In photodynamic therapy (PDT) a photosensitizer – a molecule that is activated by light – is administered and exposed to a light source. This leads both to destruction of cells targeted by the particular type of photosensitizer, and immunomodulation. Given the ease with which photosensitizers and light can be delivered to the skin, it should come as no surprise that PDT is an increasingly utilized therapeutic in dermatology. PDT is used commonly to treat precancerous cells, sun-damaged skin, and acne. It has reportedly also been used to treat other conditions including inflammatory disorders and cutaneous infections. This review discusses the principles behind how PDT is used in dermatology, as well as evidence for current applications of PDT. PMID:24899818

  16. Antiviral chemotherapy in veterinary medicine: current applications and perspectives.

    Science.gov (United States)

    Dal Pozzo, F; Thiry, E

    2014-12-01

    The current situation in the use of antiviral drugs in veterinary medicine is characterised by a novel and optimistic approach.Viruses of veterinary importance are still used as animal models in the developmentof human therapeutics, but there is growing interest in many of these viruses in the identification of antiviral molecules for use in both livestock and companion animals. The use of antiviral drugs in livestock animals is envisaged for the treatment or control of disease on a large scale (mass treatment), whereas in companion animals an individual approach is favoured. An overview of the most recent examples of research in the use of antivirals in veterinary medicine is presented, with particular emphasis on their in vivo applications.

  17. Current and potential applications of bismuth-based drugs.

    Science.gov (United States)

    Keogan, Donal M; Griffith, Darren M

    2014-09-23

    : Bismuth compounds have been used extensively as medicines and in particular for the treatment of gastrointestinal ailments. In addition to bismuth's well known gastroprotective effects and efficacy in treating H. pylori infection it also has broad anti-microbial, anti-leishmanial and anti-cancer properties. Aspects of the biological chemistry of bismuth are discussed and biomolecular targets associated with bismuth treatment are highlighted. This review strives to provide the reader with an up to date account of bismuth-based drugs currently used to treat patients and discuss potential medicinal applications of bismuth drugs with reference to recent developments in the literature. Ultimately this review aims to encourage original contributions to this exciting and important field.

  18. DOE Center of Excellence in Medical Laser Applications. Final report, December 1, 1994--November 30, 1997

    Energy Technology Data Exchange (ETDEWEB)

    Jacques, S.L.

    1998-01-01

    An engineering network of collaborating medical laser laboratories are developing laser and optical technologies for medical diagnosis and therapy and are translating the engineering into medical centers in Portland OR, Houston TX, and Galveston TX. The Center includes the University of Texas M.D. Anderson Cancer Center, the University of Texas-Austin, Texas A and M University, Rice University, the University Texas Medical Branch-Galveston, Oregon Medical Laser Center (Providence St. Vincent Medical Center, Oregon Health Sciences University, and Oregon Graduate Institute, Portland, OR), and the University of Oregon. Diagnostics include reflectance, fluorescence, Raman IR, laser photoacoustics, optical coherence tomography, and several new video techniques for spectroscopy and imaging. Therapies include photocoagulation therapy, laser welding, pulsed laser ablation, and light-activated chemotherapy of cancer (photodynamic therapy, or PDT). Medical applications reaching the clinic include optical monitoring of hyperbilirubinemia in newborns, fluorescence detection of cervical dysplasia, laser thrombolysis of blood clots in heart attack and brain stroke, photothermal coagulant of benign prostate hyperplasia, and PDT for both veterinary and human cancer. New technologies include laser optoacoustic imaging of breast tumors and hemorrhage in head trauma and brain stroke, quality control monitoring of dosimetry during PDT for esophageal and lung cancer, polarization video reflectometry of skin cancer, laser welding of artificial tissue replacements, and feedback control of laser welding.

  19. LASER APPLICATIONS: Laser air-jet engine: the action of shock waves at low laser pulse repetition rates

    Science.gov (United States)

    Apollonov, V. V.; Tishchenko, V. N.

    2007-08-01

    The impact and thermal action of laser sparks on the reflector of a laser engine in which the propulsion is produced by repetitively pulsed radiation is estimated. It is shown that for a low pulse repetition rate, the thermal contact of a plasma with the reflector and strong dynamic resonance loads are inevitable. These difficulties can be surmounted by using the method based on the merging of shock waves at a high pulse repetition rate.

  20. High energy, single frequency, tunable laser source operating in burst mode for space based lidar applications

    Science.gov (United States)

    Cosentino, Alberto; Mondello, Alessia; Sapia, Adalberto; D'Ottavi, Alessandro; Brotini, Mauro; Nava, Enzo; Stucchi, Emanuele; Trespidi, Franco; Mariottini, Cristina; Wazen, Paul; Falletto, Nicolas; Fruit, Michel

    2017-11-01

    This paper describes the laser transmitter assembly used in the ALADIN instrument currently in C/D development phase for the ESA ADM-AEOLUS mission (EADS Astrium as prime contractor for the satellite and the instrument). The Laser Transmitter Assembly (TXA), based on a diode pumped tripled Nd:YAG laser, is used to generate tunable laser pulses of 150 mJ at a nominal wavelength of 355 nm. This laser is operated in burst mode, with a pulse repetition cycle of 100 Hz. The TXA is composed of the following units: a diodepumped CW Nd:YAG Laser named Reference Laser Head (RLH), used to inject a diode-pumped, Q-switched, amplified and frequency tripled Nd:YAG Laser working in the third harmonic referred as Power Laser Head (PLH) and a Transmitter Laser Electronics (TLE) containing all the control and power electronics needed for PLH and RLH operation. The TXA is made by an European consortium under the leadership of Galileo Avionica (It), and including CESI (It), Quantel (Fr), TESAT (Ge) and Thales (Fr).

  1. 6th International Workshop on Application of Lasers in Atomic Nuclei Research

    CERN Document Server

    Błaszczak, Z; Marinova, K; LASER 2004

    2006-01-01

    6th International Workshop on Application of Lasers in Atomic Nuclei Research, LASER 2004, held in Poznan, Poland, 24-27 May, 2004 Researchers and graduate students interested in the Mössbauer Effect and its applications will find this volume indispensable. The volume presents the most recent developments in the methodology of Mössbauer spectroscopy. Reprinted from Hyperfine Interactions (HYPE) Volume 162, 1-4

  2. AlGaInN laser diode technology for defence, security and sensing applications

    Science.gov (United States)

    Najda, Stephen P.; Perlin, Piotr; Suski, Tadek; Marona, Lucja; Boćkowski, Mike; Leszczyński, Mike; Wisniewski, Przemek; Czernecki, Robert; Kucharski, Robert; Targowski, Grzegorz; Watson, Scott; Kelly, Antony E.

    2014-10-01

    The latest developments in AlGaInN laser diode technology are reviewed for defence, security and sensing applications. The AlGaInN material system allows for laser diodes to be fabricated over a very wide range of wavelengths from u.v., i.e, 380nm, to the visible, i.e., 530nm, by tuning the indium content of the laser GaInN quantum well. Advantages of using Plasma assisted MBE (PAMBE) compared to more conventional MOCVD epitaxy to grow AlGaInN laser structures are highlighted. Ridge waveguide laser diode structures are fabricated to achieve single mode operation with optical powers of <100mW in the 400-420nm wavelength range that are suitable for telecom applications. Visible light communications at high frequency (up to 2.5 Gbit/s) using a directly modulated 422nm Gallium-nitride (GaN) blue laser diode is reported. High power operation of AlGaInN laser diodes is demonstrated with a single chip, AlGaInN laser diode `mini-array' with a common p-contact configuration at powers up to 2.5W cw at 410nm. Low defectivity and highly uniform GaN substrates allow arrays and bars of nitride lasers to be fabricated. GaN laser bars of up to 5mm with 20 emitters, mounted in a CS mount package, give optical powers up to 4W cw at ~410nm with a common contact configuration. An alternative package configuration for AlGaInN laser arrays allows for each individual laser to be individually addressable allowing complex free-space and/or fibre optic system integration within a very small form-factor.or.

  3. Mechanisms and applications of plant growth promoting rhizobacteria: Current perspective

    Directory of Open Access Journals (Sweden)

    Munees Ahemad

    2014-01-01

    Full Text Available Plant growth promoting rhizobacteria are the soil bacteria inhabiting around/on the root surface and are directly or indirectly involved in promoting plant growth and development via production and secretion of various regulatory chemicals in the vicinity of rhizosphere. Generally, plant growth promoting rhizobacteria facilitate the plant growth directly by either assisting in resource acquisition (nitrogen, phosphorus and essential minerals or modulating plant hormone levels, or indirectly by decreasing the inhibitory effects of various pathogens on plant growth and development in the forms of biocontrol agents. Various studies have documented the increased health and productivity of different plant species by the application of plant growth promoting rhizobacteria under both normal and stressed conditions. The plant-beneficial rhizobacteria may decrease the global dependence on hazardous agricultural chemicals which destabilize the agro-ecosystems. This review accentuates the perception of the rhizosphere and plant growth promoting rhizobacteria under the current perspectives. Further, explicit outlooks on the different mechanisms of rhizobacteria mediated plant growth promotion have been described in detail with the recent development and research. Finally, the latest paradigms of applicability of these beneficial rhizobacteria in different agro-ecosystems have been presented comprehensively under both normal and stress conditions to highlight the recent trends with the aim to develop future insights.

  4. Current and emerging applications of 3D printing in medicine.

    Science.gov (United States)

    Liaw, Chya-Yan; Guvendiren, Murat

    2017-06-07

    Three-dimensional (3D) printing enables the production of anatomically matched and patient-specific devices and constructs with high tunability and complexity. It also allows on-demand fabrication with high productivity in a cost-effective manner. As a result, 3D printing has become a leading manufacturing technique in healthcare and medicine for a wide range of applications including dentistry, tissue engineering and regenerative medicine, engineered tissue models, medical devices, anatomical models and drug formulation. Today, 3D printing is widely adopted by the healthcare industry and academia. It provides commercially available medical products and a platform for emerging research areas including tissue and organ printing. In this review, our goal is to discuss the current and emerging applications of 3D printing in medicine. A brief summary on additive manufacturing technologies and available printable materials is also given. The technological and regulatory barriers that are slowing down the full implementation of 3D printing in the medical field are also discussed.

  5. Modeling streamflow from coupled airborne laser scanning and acoustic Doppler current profiler data

    Science.gov (United States)

    Norris, Lam; Kean, Jason W.; Lyon, Steve

    2016-01-01

    The rating curve enables the translation of water depth into stream discharge through a reference cross-section. This study investigates coupling national scale airborne laser scanning (ALS) and acoustic Doppler current profiler (ADCP) bathymetric survey data for generating stream rating curves. A digital terrain model was defined from these data and applied in a physically based 1-D hydraulic model to generate rating curves for a regularly monitored location in northern Sweden. Analysis of the ALS data showed that overestimation of the streambank elevation could be adjusted with a root mean square error (RMSE) block adjustment using a higher accuracy manual topographic survey. The results of our study demonstrate that the rating curve generated from the vertically corrected ALS data combined with ADCP data had lower errors (RMSE = 0.79 m3/s) than the empirical rating curve (RMSE = 1.13 m3/s) when compared to streamflow measurements. We consider these findings encouraging as hydrometric agencies can potentially leverage national-scale ALS and ADCP instrumentation to reduce the cost and effort required for maintaining and establishing rating curves at gauging station sites similar to the Röån River.

  6. Photoelectrolysis of water at high current density - Use of ultraviolet laser excitation

    Science.gov (United States)

    Bocarsly, A. B.; Bolts, J. M.; Cummins, P. G.; Wrighton, M. S.

    1977-01-01

    The behavior of TiO2 and SrTiO3 photoanodes in cells for the photoelectrolysis of H2O has been investigated for high-intensity 351-,364-nm excitation from an Ar ion laser. Intensities up to 380 W/sq cm have been used. For TiO2 a small amount of surface decomposition is found after irradiation at high intensity, whereas SrTiO3 undergoes no detectable changes. Current-voltage properties for both electrodes are essentially independent of light intensity up to the level of 380 W/sq cm, and there is little if any change in quantum efficiency for electron flow. Photocurrent densities have been shown to exceed 5 A/sq cm for O2 evolution. Data show that the energy storage rate associated with the SrTiO3 photoelectrolysis can exceed 30 W/sq cm; this represents the highest demonstrated rate of sustained optical-to-chemical energy conversion.

  7. Peltier current lead experiment and their applications for superconducting magnets

    Science.gov (United States)

    Yamaguchi, Satarou; Yamaguchi, Takayuki; Nakamura, Kenji; Hasegawa, Yasuhiro; Okumura, Haruhiko; Sato, Ken

    2004-01-01

    Many applications of superconductivity are studied because they are basically nondissipative systems; however, electric power is spent to keep them at low temperature. If heat leakage is high, the advantage of the superconductivity will be reduced or disappear, and therefore we must reduce the heat leakage as much as we can in the actual system. The Peltier current lead (PCL) was proposed to reduce heat leakage from the electric circuit of the superconducting magnet system. PCL is composed of thermoelectric semiconductors, metal leads, and high temperature superconducting (HTS) leads. Bismuth-tellurium alloys (BiTe) are used as the thermoelectric semiconductors in the experiment, and these are placed on the room temperature side. Optimum design of the PCL is conducted to solve a heat leakage equation, and depends on the transport parameters such as thermal conductivity, electric resistivity, and Seebeck coefficient of the materials of the PCL. The thermal conductivity of the BiTe is about 0.4% of the copper's, and we can expect the Peltier cooling by using this material. Therefore, we can expect the large temperature difference of the BiTe and reduce the heat leakage. The experiment has been done and the cold-end temperature of the thermoelectric BiTe is around 200 K both in the experiment and the numerical calculation. The temperature difference of 4 mm thickness of the BiTe exceeds 70 K for 150 A in both the experiment and the calculation. Therefore, the principle was proven in the experiments, and the reduction of the heat leakage is up to 35% for the current lead included in the HTS current lead. Here, we also mentioned and proposed the various types of the PCL for the different kinds of superconducting magnet systems in this article.

  8. One visit providing desirable smile by laser application.

    Science.gov (United States)

    Fekrazad, Reza; Chiniforush, Nasim

    2014-01-01

    Providing desirable smile is one of the main concerns in cosmetic dentistry. Hyperpigmentation is one of the esthetic concerns especially in gummy smile patients. Lasers with different wavelength are used for oral surgery including Carbon Dioxide Laser (CO2), Neodymium-Doped Yttrium Aluminium Garnet (Nd:YAG), Erbium family and diode laser. In this case, all esthetic procedures including gingival depigmentation, caries detection and removal were done by laser technology in one session. A 40- year-old male with a chief complaint of black gingiva in upper jaw was referred. The right side of maxillary was anesthetized and depigmentation was done by Erbium, Chromium doped Yttrium Scandium Gallium Garnet (Er-Cr: YSGG) laser. Due to scores obtained from Diagnodent which indicated caries in dentin, the cavities were prepared by Er-Cr:YSGG laser. The cavities were restored by composite resin. The patient was advised to keep oral hygiene instructions and use mouthwash. The patient reported no pain after surgery and did not use any systemic antibiotic. After 4 weeks, complete healing was observed. Considering acceptable clinical outcome, Er-Cr: YSGG laser can be considered as an effective method for combination of soft and hard tissue treatment.

  9. High resolution applications of laser-induced breakdown spectroscopy for environmental and forensic applications

    International Nuclear Information System (INIS)

    Martin, Madhavi Z.; Labbe, Nicole; Andre, Nicolas; Harris, Ronny; Ebinger, Michael; Wullschleger, Stan D.; Vass, Arpad A.

    2007-01-01

    Laser-induced breakdown spectroscopy (LIBS) has been used in the elemental analysis for a variety of environmental samples and as a proof of concept for a host of forensic applications. In the first application, LIBS was used for the rapid detection of carbon from a number of different soil types. In this application, a major breakthrough was achieved by using a multivariate analytical approach that has brought us closer towards a 'universal calibration curve'. In a second application, it has been demonstrated that LIBS in combination with multivariate analysis can be employed to analyze the chemical composition of annual tree growth rings and correlate them to external parameters such as changes in climate, forest fires, and disturbances involving human activity. The objectives of using this technology in fire scar determinations are: 1) To determine the characteristic spectra of wood exposed to forest fires and 2) To examine the viability of this technique for detecting fire occurrences in stems that did not develop fire scars. These examples demonstrate that LIBS-based techniques are inherently well suited for diverse environmental applications. LIBS was also applied to a variety of proof of concept forensic applications such as the analysis of cremains (human cremation remains) and elemental composition analysis of prosthetic implants

  10. Optimized Laser Thermal Annealing on Germanium for High Dopant Activation and Low Leakage Current

    DEFF Research Database (Denmark)

    Shayesteh, Maryam; O' Connell, Dan; Gity, Farzan

    2014-01-01

    In this paper, state-of-the-art laser thermal annealing is used to fabricate Ge diodes. We compared the effect of laser thermal annealing (LTA) and rapid thermal annealing (RTA) on dopant activation and electrical properties of phosphorus and Arsenic-doped n +/p junctions. Using LTA, high carrier...

  11. Current status of the driver laser system for intense terahertz wave generation

    International Nuclear Information System (INIS)

    Tanaka, Momoko; Ochi, Yoshihiro; Kosuge, Atsushi; Okada, Hajime; Kiriyama, Hiromitsu; Mori, Michiaki; Tsubouchi, Masaaki; Nagashima, Keisuke

    2014-01-01

    We have constructed a high power kHz laser system using Yb:YAG thin-disk as a gain medium for a driver laser of THz wave generation. A 4-bounce regenerative amplifier is constructed and output energy up to 10 mJ is obtained. Using compressed pulse, we demonstrated THz wave generation with LiNbO 3 crystal. (author)

  12. Femtosecond laser 3D micromachining for microfluidic and optofluidic applications

    CERN Document Server

    Sugioka, Koji

    2013-01-01

    Femtosecond lasers opened up new avenue in materials processing due to its unique features of ultrashort pulse width and extremely high peak intensity. One of the most important features of femtosecond laser processing is that strong absorption can be induced even by materials which are transparent to the femtosecond laser beam due to nonlinear multiphoton absorption. The multiphoton absorption allows us to perform not only surface but also three-dimensionally internal microfabrication of transparent materials such as glass. This capability makes it possible to directly fabricate three-dimensi

  13. Electrospun Polymer Fiber Lasers for Applications in Vapor Sensing

    DEFF Research Database (Denmark)

    Krämmer, Sarah; Laye, Fabrice; Friedrich, Felix

    2017-01-01

    A sensing approach based on laser emissionfrom polymer fiber networks is presented. Poly(methyl methacrylate) (PMMA) fibers doped with a laser dye are fabricated by electrospinning. They form random loop resonators, which show laser emission upon optical pumping. The shift of the spectral position...... of the narrow lasing modes upon uptake of alcohol vapors (model vapors are methanol and ethanol) serves as sensor signal. Thus, the high sensitivity related to the spectral line shifts of cavity-based transducers can be combined with the fiber's large surface to volume ratio. The resulting optical sensors...

  14. Laser gyros in system application with rate-bias technique

    Science.gov (United States)

    Bueschelberger, H. J.; Handrich, E.; Malthan, H.; Schmidt, G.

    The state of the art of the dithered laser gyro is briefly reviewed. It is noted that, despite the lock-in problem and the disadvantages of the dither mechanization used to date, the laser gyro has established itself in high-accuracy (better than 1 NM/h) strapdown navigation systems. This success can be attributed to such laser gyro advantages as digital output, the absence of fast-rotating parts, g insensitivity, high scalefactor accuracy, and high reliability. The rate bias concept is then examined, and the advantages of rate bias technology are discussed.

  15. High average power, diode pumped petawatt laser systems: a new generation of lasers enabling precision science and commercial applications

    Science.gov (United States)

    Haefner, C. L.; Bayramian, A.; Betts, S.; Bopp, R.; Buck, S.; Cupal, J.; Drouin, M.; Erlandson, A.; Horáček, J.; Horner, J.; Jarboe, J.; Kasl, K.; Kim, D.; Koh, E.; Koubíková, L.; Maranville, W.; Marshall, C.; Mason, D.; Menapace, J.; Miller, P.; Mazurek, P.; Naylon, A.; Novák, J.; Peceli, D.; Rosso, P.; Schaffers, K.; Sistrunk, E.; Smith, D.; Spinka, T.; Stanley, J.; Steele, R.; Stolz, C.; Suratwala, T.; Telford, S.; Thoma, J.; VanBlarcom, D.; Weiss, J.; Wegner, P.

    2017-05-01

    Large laser systems that deliver optical pulses with peak powers exceeding one Petawatt (PW) have been constructed at dozens of research facilities worldwide and have fostered research in High-Energy-Density (HED) Science, High-Field and nonlinear physics [1]. Furthermore, the high intensities exceeding 1018W/cm2 allow for efficiently driving secondary sources that inherit some of the properties of the laser pulse, e.g. pulse duration, spatial and/or divergence characteristics. In the intervening decades since that first PW laser, single-shot proof-of-principle experiments have been successful in demonstrating new high-intensity laser-matter interactions and subsequent secondary particle and photon sources. These secondary sources include generation and acceleration of charged-particle (electron, proton, ion) and neutron beams, and x-ray and gamma-ray sources, generation of radioisotopes for positron emission tomography (PET), targeted cancer therapy, medical imaging, and the transmutation of radioactive waste [2, 3]. Each of these promising applications requires lasers with peak power of hundreds of terawatt (TW) to petawatt (PW) and with average power of tens to hundreds of kW to achieve the required secondary source flux.

  16. Applications of compact laser-driven EUV/XUV plasma sources

    Science.gov (United States)

    Barkusky, Frank; Bayer, Armin; Döring, Stefan; Flöter, Bernhard; Großmann, Peter; Peth, Christian; Reese, Michael; Mann, Klaus

    2009-05-01

    In recent years, technological developments in the area of extreme ultraviolet lithography (EUVL) have experienced great improvements. So far, intense light sources based on discharge or laser plasmas, beam steering and imaging optics as well as sensitive detectors are available. Currently, applications of EUV radiation apart from microlithography, such as metrology, high-resolution microscopy, or surface analysis come more and more into focus. In this contribution we present an overview on the EUV/XUV activities of the Laser-Laboratorium Göttingen based on table-top laser-produced plasma (LPP) sources. As target materials gaseous or liquid jets of noble gases or solid Gold are employed. Depending on the applications, the very clean but low intense gaseous targets are mainly used for metrology, whereas the targets for high brilliances (liquid, solid) are used for microscopy and direct structuring. For the determination of interaction mechanisms between EUV radiation and matter, currently the solid Gold target is used. In order to obtain a small focal spot resulting in high EUV fluence, a modified Schwarzschild objective consisting of two spherical mirrors with Mo/Si multilayer coatings is adapted to this source. By demagnified (10x) imaging of the Au plasma an EUV spot of 3 μm diameter with a maximum energy density of ~1.3 J/cm2 is generated (pulse duration 8.8 ns). First applications of this integrated source and optics system reveal its potential for high-resolution modification and direct structuring of solid surfaces. For chemical analysis of various samples a NEXAFS setup was developed. It consists of a LPP, using gaseous Krypton as a broadband emitter in the water-window range, as well as a flat field spectrograph. The laboratory system is set to the XUV spectral range around the carbon K-edge (4.4 nm). The table-top setup allows measurements with spectral accuracy comparable to synchrotron experiments. NEXAFS-experiments in transmission and reflection are

  17. The GBLD: a radiation tolerant laser driver for high energy physics applications

    Science.gov (United States)

    Mazza, G.; Tavernier, F.; Moreira, P.; Rivetti, A.; Soos, C.; Troska, J.; Wyllie, K.

    2013-01-01

    The GigaBit Laser Driver (GBLD) is a radiation tolerant ASIC which is part of the GigaBit Transceiver (GBT) chipset. It is aimed to drive both edge emitting and VCSEL laser diodes at a data rate in excess of 5 Gb/s. The GBLD can provide a modulation current up to 24 mA and a bias current up to 43 mA. Pre- and de-emphasis functions are implemented to compensate for high external capacitive loads and asymmetric laser response. The chip is designed in a 130 nm CMOS technology and is powered by a single 2.5 V supply.

  18. Fabrication of Polymer Microspheres for Optical Resonator and Laser Applications.

    Science.gov (United States)

    Yamamoto, Yohei; Okada, Daichi; Kushida, Soh; Ngara, Zakarias Seba; Oki, Osamu

    2017-06-02

    This paper describes three methods of preparing fluorescent microspheres comprising π-conjugated or non-conjugated polymers: vapor diffusion, interface precipitation, and mini-emulsion. In all methods, well-defined, micrometer-sized spheres are obtained from a self-assembling process in solution. The vapor diffusion method can result in spheres with the highest sphericity and surface smoothness, yet the types of the polymers able to form these spheres are limited. On the other hand, in the mini-emulsion method, microspheres can be made from various types of polymers, even from highly crystalline polymers with coplanar, π-conjugated backbones. The photoluminescent (PL) properties from single isolated microspheres are unusual: the PL is confined inside the spheres, propagates at the circumference of the spheres via the total internal reflection at the polymer/air interface, and self-interferes to show sharp and periodic resonant PL lines. These resonating modes are so-called "whispering gallery modes" (WGMs). This work demonstrates how to measure WGM PL from single isolated spheres using the micro-photoluminescence (µ-PL) technique. In this technique, a focused laser beam irradiates a single microsphere, and the luminescence is detected by a spectrometer. A micromanipulation technique is then used to connect the microspheres one by one and to demonstrate the intersphere PL propagation and color conversion from coupled microspheres upon excitation at the perimeter of one sphere and detection of PL from the other microsphere. These techniques, µ-PL and micromanipulation, are useful for experiments on micro-optic application using polymer materials.

  19. Experiments on laser beam jitter control with applications to a shipboard free electron laser

    OpenAIRE

    Bateman, Brett E.

    2007-01-01

    A Free Electron Laser (FEL) shows potential as an effective defensive weapon for a naval ship against today's modern weapons such as supersonic anti-ship missiles. A laser can destroy these fast and highly maneuverable missiles at the speed of light. Several obstacles must be overcome to employ this weapon on a naval ship. This thesis discusses several methods for passive and active jitter control of a guided optical beam which might be employed in a FEL weapon system. Vibration experime...

  20. The third international workshop on the physics and modern applications of lasers 8-20 August, 1994

    International Nuclear Information System (INIS)

    1994-08-01

    The document contains 31 abstracts and 7 papers on lasers and optical fibers presented at the 3. international workshop on the physics and modern applications of lasers. The main topics covered include: basics in lasers, geometrical, physical and quantum optics; optical techniques for research, education and development in Africa; application of lasers in optical fibre communication, environmental studies, bio medicine, chemistry, agriculture, engineering and industry. A list of lecturers, participants and programme of activities are also given. (EAA)

  1. Miniature, Rugged, Pulsed Laser Source for LIDAR Application Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Princeton Optronics proposes to develop a high energy pulsed laser source based on a novel approach. The approach consists of a technique to combine a large number...

  2. Application of low level laser on skin cell lines

    CSIR Research Space (South Africa)

    Ndhundhuma, IM

    2010-01-01

    Full Text Available Lasers have emerged as powerful tools for tissue engineering. To examine cellular growth, and cell to cell interactions, in vitro skin models have been developed combining two major cell types of skin, keratinocytes and fibroblasts. The main...

  3. Application of fiber laser for a Higgs factory

    Energy Technology Data Exchange (ETDEWEB)

    Chou, W.

    2014-06-04

    This paper proposes a medium size(~6km) circular Higgs factory based on a photon collider. The recent breakthrough in fiber laser technology by means of a coherent amplifier network makes such a collider feasible and probably also affordable.

  4. Synchronization properties of chaotic semiconductor lasers and applications to encryption

    Science.gov (United States)

    Mirasso, Claudio R.; Vicente, Raúl; Colet, Pere; Mulet, Josep; Pérez, Toni

    2004-08-01

    We review the main properties of two unidirectionally coupled single-mode semiconductor lasers ( master-slave configuration). Our analysis is based on numerical simulations of a rate equations model. The emitter, or master laser, is assumed to be an external-cavity single-mode semiconductor laser subject to optical feedback that operates in a chaotic regime. The receiver, or slave laser, is similar to the emitter but can either operate in a chaotic regime, as the emitter (closed loop configuration), or without optical feedback and consequently under CW when it is uncoupled (open loop configuration). This configuration is one of the most simple and useful configuration for chaos based communication systems and data encryption. To cite this article: C.R. Mirasso et al., C. R. Physique 5 (2004).

  5. Iodine Stabilized Seed Laser for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This SBIR Phase I effort proposes to establish the feasibility of leveraging advances in compact laser technology with integration of space qualified techniques into...

  6. Iodine Stabilized Seed Laser for Space Applications Project

    Data.gov (United States)

    National Aeronautics and Space Administration — The overall goal of this SBIR effort is development of a space qualifiable, compact, frequency stabilized seed laser with low SWaP for routine use in NASA LaRC's...

  7. Development of laser preventive maintenance technology and application for PWRs

    International Nuclear Information System (INIS)

    Yoda, M.; Saeki, R.; Kato, H.; Chida, I.

    2008-01-01

    We developed a laser peening technology to prevent the stress corrosion cracking (SCC) on nuclear reactor in-core components. Since 2004, we started to apply it to PWRs and have practiced it three times successfully for Ikata-1,2 of Shikoku Electric Power Company as the SCC preventive maintenance technology for Alloy 600 materials. It is expected the laser peening technology will be applied to many other plants. (author)

  8. Laser control of atomic beam motion and applications

    International Nuclear Information System (INIS)

    Balykin, V.I.; Letokhov, V.S.

    1987-01-01

    The authors present the results of an experimental investigation of the control of atomic beam motion by the light pressure of laser radiation. Collimation, focusing and reflection of the atomic beam are considered. Collimation of the atomic beam is achieved by the interaction of laser radiation with atoms, when the light pressure force depends only on the atom's velocity. A similar regime of atomic beam interaction with radiation was performed with transversal irradiation of a beam by the axis-symmetrical field. The axis-symmetrical field was formed by laser radiation reflected from the conical mirror surface of a reflecting axicon. The axis of the atomic beam coincided with that of the axicon. The collimation regime was reached under negative detuning of the laser radiation frequency from the atomic transition frequency by a value equal to several homogeneous widths. With positive detuning by the same value the regime of beam decollimation was observed. The density of atoms on the beam axis was changed by 10 3 times, when the collimation regime was replaced by that of decollimation. Focusing of the atomic beam was achieved by light pressure dependent on the atomic coordinate. Focusing was performed within the field configuration formed by divergent laser Gaussian beams propagating in the direction +- X, +- Y of a Cartesian coordinate system. Waists of the laser beams were an equal distance from the atomic beam axis. With an atomic beam propagating along the z axis, expressions for local distance and a formula for the laser lens were obtained. Focusing of the atomic beam was experimentally accomplished, and the image of the atomic beam was received. In this work they also investigated reflection of the atomic beam by laser radiation. The possibility of creating the optics of a neutral atomic beam is shown

  9. Laser Ignition Technology for Bi-Propellant Rocket Engine Applications

    Science.gov (United States)

    Thomas, Matthew E.; Bossard, John A.; Early, Jim; Trinh, Huu; Dennis, Jay; Turner, James (Technical Monitor)

    2001-01-01

    The fiber optically coupled laser ignition approach summarized is under consideration for use in igniting bi-propellant rocket thrust chambers. This laser ignition approach is based on a novel dual pulse format capable of effectively increasing laser generated plasma life times up to 1000 % over conventional laser ignition methods. In the dual-pulse format tinder consideration here an initial laser pulse is used to generate a small plasma kernel. A second laser pulse that effectively irradiates the plasma kernel follows this pulse. Energy transfer into the kernel is much more efficient because of its absorption characteristics thereby allowing the kernel to develop into a much more effective ignition source for subsequent combustion processes. In this research effort both single and dual-pulse formats were evaluated in a small testbed rocket thrust chamber. The rocket chamber was designed to evaluate several bipropellant combinations. Optical access to the chamber was provided through small sapphire windows. Test results from gaseous oxygen (GOx) and RP-1 propellants are presented here. Several variables were evaluated during the test program, including spark location, pulse timing, and relative pulse energy. These variables were evaluated in an effort to identify the conditions in which laser ignition of bi-propellants is feasible. Preliminary results and analysis indicate that this laser ignition approach may provide superior ignition performance relative to squib and torch igniters, while simultaneously eliminating some of the logistical issues associated with these systems. Further research focused on enhancing the system robustness, multiplexing, and window durability/cleaning and fiber optic enhancements is in progress.

  10. Novel solid state lasers for Lidar applications at 2 μm

    Science.gov (United States)

    Della Valle, G.; Galzerano, G.; Toncelli, A.; Tonelli, M.; Laporta, P.

    2005-09-01

    A review on the results achieved by our group in the development of novel solid-state lasers for Lidar applications at 2 μm is presented. These lasers, based on fluoride crystals (YLF4, BaY2F8, and KYF4) doped with Tm and Ho ions, are characterized by high-efficiency and wide wavelength tunability around 2 μm. Single crystals of LiYF4, BaY2F8, and KYF4 codoped with the same Tm3+ and Ho3+ concentrations were successfully grown by the Czochralski method. The full spectroscopic characterization of the different laser crystals and the comparison between the laser performance are presented. Continuous wave operation was efficiently demonstrated by means of a CW diode-pumping. These oscillators find interesting applications in the field of remote sensing (Lidar and Dial systems) as well as in high-resolution molecular spectroscopy, frequency metrology, and biomedical applications.

  11. Development and application of laser techniques for studying fuel dynamics and NO formation in engines

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Oeivind

    2000-11-01

    was detected using two-photon induced fluorescence. The two signals were imaged on different portions of the same CCD camera. Water is used in a number of combustion applications, but it would be a great advantage if this technique could be developed for application in fuel sprays. It could then be used as an alternative to the fluorescent-exciplex technique commonly used for two-phase detection in such applications. The exciplex technique requires an oxygen-free atmosphere and can thus not be used in real combustion environments. Fuel dynamics have also been studied in DME sprays, both in a combustion vessel and in an optical diesel truck engine. The studies were made using laser-Rayleigh imaging and provided interesting information about the general development and autoignition of these sprays. Among other things it was found that autoignition occurred differently in the two environments. In the vessel, the sprays ignited around the periphery where fuel/air mixtures were close to stoichiometric. In the engine, however ignition occurred volumetrically throughout the cross section of the spray vortex. There is reason to believe that mixtures were fuel-rich in this region. The explanation for the different behaviours is assumed to be found in the temperature and density conditions of the atmospheres into which the sprays were injected. The results show that sprays can behave quite differently in different environments. A thorough study of the effects of temperature, density, and EGR on autoignition in sprays is highly desirable, since current models do not seem to give a general description of the phenomenon. Both the measurements in the DISI engine and the NO measurements in the SI engine show that laser spectroscopic techniques can be used for improving and developing computer-based design tools. In the case of the DISI engine, the data were used to validate results from CFD codes used for engine design. The NO data provided a database for development of a model for

  12. High-frequency strontium vapor laser for biomedical applications

    Science.gov (United States)

    Hvorostovsky, A.; Kolmakov, E.; Kudashev, I.; Redka, D.; Kancer, A.; Kustikova, M.; Bykovskaya, E.; Mayurova, A.; Stupnikov, A.; Ruzankina, J.; Tsvetkov, K.; Lukyanov, N.; Paklinov, N.

    2018-02-01

    Sr-laser with high pulse repetition rate and high peak radiation power is a unique tool for studying rapidly occurring processes in time (plasma diagnostics, photoablation, etc.). In addition, the study of the frequency characteristics of the active medium of the laser helps to reveal the physics of the formation of an inverse medium in metal vapor lasers. In this paper, an experimental study of an Sr-laser with an active volume of 5.8 cm3 in the pulse repetition frequency range from 25 to 200 kHz is carried out, and a comparison with the frequency characteristics of media with large active volumes is given. We considered the frequency characteristics of the active medium in two modes: at a constant energy in the excitation pulse CU2 / 2 and at a constant average power consumed by the rectifier. In the presented work with a small-volume GRT using the TASITR-5/12 TASITRON switch, a laser was generated for Pairs of strontium at a CSF of 200 kHz. The behavior of the characteristics of the generation lines of 6.456 μm, 1 μm, and 3 μm at increased repetition frequencies is considered. Using the example of large-volume GRT, it is shown that tubes with a large active volume increase their energy characteristics with the growth of the CSF. The possibility of laser operation at pulse repetition rates above 200 kHz is shown.

  13. Eliminating Ground Current in a Transformerless Photovoltaic Application

    DEFF Research Database (Denmark)

    Lopez, Ocar; Freijedo, Francisco D.; Yepes, Alejandro G.

    2010-01-01

    additional ground currents due to the ground parasitic capacitance. These currents increase conducted and radiated electromagnetic emissions, harmonics injected in the utility grid, and losses. Amplitude and spectrum of the ground current depend on the converter topology, the switching strategy...

  14. In vitro biological outcome of laser application for modification or processing of titanium dental implants.

    Science.gov (United States)

    Hindy, Ahmed; Farahmand, Farzam; Tabatabaei, Fahimeh Sadat

    2017-07-01

    There are numerous functions for laser in modern implant dentistry including surface treatment, surface coating, and implant manufacturing. As laser application may potentially improve osseointegration of dental implants, we systematically reviewed the literature for in vitro biological responses to laser-modified or processed titanium dental implants. The literature was searched in PubMed, ISI Web, and Scopus, using keywords "titanium dental implants," "laser," "biocompatibility," and their synonyms. After screening the 136 references obtained, 28 articles met the inclusion criteria. We found that Nd:YAG laser was the most commonly used lasers in the treatment or processing of titanium dental implants. Most of the experiments used cell attachment and cell proliferation to investigate bioresponses of the implants. The most commonly used cells in these assays were osteoblast-like cells. Only one study was conducted in stem cells. These in vitro studies reported higher biocompatibility in laser-modified titanium implants. It seems that laser radiation plays a vital role in cell response to dental implants; however, it is necessary to accomplish more studies using different laser types and parameters on various cells to offer a more conclusive result.

  15. Lasers

    OpenAIRE

    Passeron, Thierry

    2012-01-01

    International audience; 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 succesfully 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-aulait macules should not b...

  16. Laser

    OpenAIRE

    Du, K.; Loosen, P.; Herziger, G.

    1991-01-01

    Laser, consisting of a beam path multiple-folded by means of two cavity end mirrors and having at least one reflector folding the laser beam retroreflectively, the axis of which is arranged offset in parallel to the axis of a further reflector. So that the laser exhibits an improved beam quality while retaining its comparatively low adjustment sensitivity, the beam path is folded at least twice by means of the retoreflective reflector.

  17. 5-μm vertical external-cavity surface-emitting laser (VECSEL) for spectroscopic applications

    Science.gov (United States)

    Rahim, M.; Khiar, A.; Felder, F.; Fill, M.; Zogg, H.; Sigrist, M. W.

    2010-08-01

    Mid-IR tunable VECSELs (Vertical External-Cavity Surface-Emitting Lasers) emitting at 4-7 μm wavelengths and suitable for spectroscopic sensing applications are described. They are realized with lead-chalcogenide (IV-VI) narrow band gap materials. The active part, a single 0.6-2-μm thick PbTe or PbSe gain layer, is grown onto an epitaxial Bragg mirror consisting of two or three Pb1- y Eu y Te/BaF2 quarter-wavelength layer pairs. All layers are deposited by MBE in a single run employing a BaF2 or Si substrate, no further processing is needed. The cavity is completed with an external curved top mirror, which is again realized with an epitaxial Bragg structure. Pumping is performed optically with a 1.5-μm laser. Maximum output power for pulsed operation is currently up to >1 Wp at -173°C and >10 mW at 10°C. In continuous wave (CW) operation, 18 mW at 100 K are reached. Still higher operating temperatures and/or powers are expected with better heat-removal structures and better designs employing QW (Quantum-Wells). Advantages of mid-IR VECSELs compared to edge-emitting lasers are their very good beam quality (circular beam with 15 μm are accessible with Pb1- y X y Z (X=Sr, Eu, Sn, Z=Se, Te) and/or including QW.

  18. Improved performance of high average power semiconductor arrays for applications in diode pumped solid state lasers

    International Nuclear Information System (INIS)

    Beach, R.; Emanuel, M.; Benett, W.; Freitas, B.; Ciarlo, D.; Carlson, N.; Sutton, S.; Skidmore, J.; Solarz, R.

    1994-01-01

    The average power performance capability of semiconductor diode laser arrays has improved dramatically over the past several years. These performance improvements, combined with cost reductions pursued by LLNL and others in the fabrication and packaging of diode lasers, have continued to reduce the price per average watt of laser diode radiation. Presently, we are at the point where the manufacturers of commercial high average power solid state laser systems used in material processing applications can now seriously consider the replacement of their flashlamp pumps with laser diode pump sources. Additionally, a low cost technique developed and demonstrated at LLNL for optically conditioning the output radiation of diode laser arrays has enabled a new and scalable average power diode-end-pumping architecture that can be simply implemented in diode pumped solid state laser systems (DPSSL's). This development allows the high average power DPSSL designer to look beyond the Nd ion for the first time. Along with high average power DPSSL's which are appropriate for material processing applications, low and intermediate average power DPSSL's are now realizable at low enough costs to be attractive for use in many medical, electronic, and lithographic applications

  19. Spectroscopy Methods and Applications of the Tor Vergata Laser-Plasma Facility Driven by GW-Level Laser System

    Directory of Open Access Journals (Sweden)

    M. Francucci

    2011-01-01

    GW, tabletop, multistage Nd:YAG/Glass laser system, delivering infrared (IR pulses with nanosecond width and 1064 nm wavelength (TEM00 mode. Its applications are discussed providing: wide analysis of IR → soft X-ray conversion efficiency (1.3–1.55 keV; measures and modeling of line emission in soft X-ray spectra, such as those from zinc plasma near Ne-like Zn XXI and from barium plasma near Ni-like Ba XXIX. Particular attention is devoted to high-n dielectronic Rydberg satellites for finding a useful diagnostic tool for plasma conditions. Dependence of plasma spectra on laser parameters is shown. Finally, microradiography applications are presented for thin biological samples. Images permit to visualize specific structures and detect bioaccumulation sites due to contamination from pollutants.

  20. High Tc superconducting current leads laser fabrication

    Directory of Open Access Journals (Sweden)

    Díez, J. C.

    1998-04-01

    Full Text Available In this work is described a laser float zone melting method designed in our laboratory to the development of superconductor Bi2Sr2CaCu2O8 current leads. The most relevant results obtained with different grown conditions and the influence of the process parameters in the properties of superconductor leads are presented.

    Las barras de alimentación basadas en el superconductor Bi2Sr2CaCu2O8 son de gran interés práctico para la fabricación de criogeneradores capaces de refrigerar bobinas superconductoras a temperaturas inferiores a 77 K e incluso cercanas a 5 K. Las propiedades mecánicas y eléctricas de dichas barras son fundamentales para determinar su grado de fiabilidad, que en última instancia determinar su aplicabilidad a escala comercial. Los parámetros de fabricación utilizando la fusión zonal inducida por láser permiten obtener fibras gruesas de este superconductor capaces de transportar elevadas corrientes a 77 K y a temperaturas inferiores, y con un comportamiento aceptable frente al ciclado térmico y al paso de elevadas intensidades de corriente eléctrica. En este trabajo se describe un sistema de fusión zonal láser diseñado en nuestro laboratorio para el desarrollo de superconductores y se resumen los resultados más significativos obtenidos según las diversas condiciones de crecimiento estudiadas, la influencia de los diversos parámetros de procesado utilizados sobre las propiedades de las fibras superconductoras obtenidas, así como su potencial uso en dispositivos prácticos.

  1. Laccase applications in biofuels production: current status and future prospects.

    Science.gov (United States)

    Kudanga, Tukayi; Le Roes-Hill, Marilize

    2014-08-01

    The desire to reduce dependence on the ever diminishing fossil fuel reserves coupled with the impetus towards green energy has seen increased research in biofuels as alternative sources of energy. Lignocellulose materials are one of the most promising feedstocks for advanced biofuels production. However, their utilisation is dependent on the efficient hydrolysis of polysaccharides, which in part is dependent on cost-effective and benign pretreatment of biomass to remove or modify lignin and release or expose sugars to hydrolytic enzymes. Laccase is one of the enzymes that are being investigated not only for potential use as pretreatment agents in biofuel production, mainly as a delignifying enzyme, but also as a biotechnological tool for removal of inhibitors (mainly phenolic) of subsequent enzymatic processes. The current review discusses the major advances in the application of laccase as a potential pretreatment strategy, the underlying principles as well as directions for future research in the search for better enzyme-based technologies for biofuel production. Future perspectives could include synergy between enzymes that may be required for optimal results and the adoption of the biorefinery concept in line with the move towards the global implementation of the bioeconomy strategy.

  2. The industrial applications of cassava: current status, opportunities and prospects.

    Science.gov (United States)

    Li, Shubo; Cui, Yanyan; Zhou, Yuan; Luo, Zhiting; Liu, Jidong; Zhao, Mouming

    2017-06-01

    Cassava (Manihot esculenta Crantz) is a drought-tolerant, staple food crop that is grown in tropical and subtropical areas. As an important raw material, cassava is a valuable food source in developing countries and is also extensively employed for producing starch, bioethanol and other bio-based products (e.g. feed, medicine, cosmetics and biopolymers). These cassava-based industries also generate large quantities of wastes/residues rich in organic matter and suspended solids, providing great potential for conversion into value-added products through biorefinery. However, the community of cassava researchers is relatively small and there is very limited information on cassava. Therefore this review summarizes current knowledge on the system biology, economic value, nutritional quality and industrial applications of cassava and its wastes in an attempt to accelerate understanding of the basic biology of cassava. The review also discusses future perspectives with respect to integrating and utilizing cassava information resources for increasing the economic and environmental sustainability of cassava industries. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  3. Current investigations into carbon nanotubes for biomedical application

    International Nuclear Information System (INIS)

    Li Xiaoming; Fan Yubo; Watari, Fumio

    2010-01-01

    The nano-dimensionality of nature has logically given rise to the interest in using nanomaterials in the biomedical field. Currently, a lot of investigations into carbon nanotubes (CNTs), as one of the typical nanomaterials, are being made for biomedical application. In this review, five parts, such as cellular functions induced by CNTs, apatite formation on CNTs, CNT-based tissue engineering scaffold, functionalized CNTs for the delivery of genes and drugs and CNT-based biosensors, are stated, which might indicate that CNTs, with a range of unique properties, appear suited as a biomaterial and may become a useful tool for tissue engineering. However, everything has two parts and CNTs is not an exception. There are still concerns about cytotoxicity and biodegradation of CNTs. Chemical fictionalization may be one of the effective ways to improve the 'disadvantages' and utilize the 'advantages' of CNTs. One of their 'disadvantages', unbiodegradable property, may be utilized by creating monitors in in vivo-engineered tissues or nanosized CNT-based biosensors. Other promising research points, for example proteins adsorbed on CNTs, use of CNTs in combination with other biomaterials to achieve the goals of tissue engineering, mineralization of CNTs and standard toxicological tests for CNTs, are also described in the conclusion and perspectives part. (topical review)

  4. Current investigations into carbon nanotubes for biomedical application

    Energy Technology Data Exchange (ETDEWEB)

    Li Xiaoming; Fan Yubo [Key Laboratory for Biomechanics and Mechanobiology of Ministry of Education, School of Biological Science and Medical Engineering, Beihang University, Beijing 100191 (China); Watari, Fumio, E-mail: x.m.li@hotmail.co [Department of Biomedical Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo 060-8586 (Japan)

    2010-04-15

    The nano-dimensionality of nature has logically given rise to the interest in using nanomaterials in the biomedical field. Currently, a lot of investigations into carbon nanotubes (CNTs), as one of the typical nanomaterials, are being made for biomedical application. In this review, five parts, such as cellular functions induced by CNTs, apatite formation on CNTs, CNT-based tissue engineering scaffold, functionalized CNTs for the delivery of genes and drugs and CNT-based biosensors, are stated, which might indicate that CNTs, with a range of unique properties, appear suited as a biomaterial and may become a useful tool for tissue engineering. However, everything has two parts and CNTs is not an exception. There are still concerns about cytotoxicity and biodegradation of CNTs. Chemical fictionalization may be one of the effective ways to improve the 'disadvantages' and utilize the 'advantages' of CNTs. One of their 'disadvantages', unbiodegradable property, may be utilized by creating monitors in in vivo-engineered tissues or nanosized CNT-based biosensors. Other promising research points, for example proteins adsorbed on CNTs, use of CNTs in combination with other biomaterials to achieve the goals of tissue engineering, mineralization of CNTs and standard toxicological tests for CNTs, are also described in the conclusion and perspectives part. (topical review)

  5. A study of particle generation during laser ablation with applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chunyi [Univ. of California, Berkeley, CA (United States)

    2005-01-01

    A study has been made of the generation of particles during laser ablation and has included size distribution measurements and observation of the formation processes. The particle size distribution with respect to different laser parameters was obtained in-line using a differential mobility analyzer (DMA) and a particle counter. The experimental results show that the particle size varies with laser energy, laser pulsewidth, ambient gas flow rate and sample properties. The results serve as a basis for controlling the size of nanoparticles generated by laser ablation. Laser shadowgraph imaging was used to study mass ejection processes and mechanisms. At higher laser irradiance, some particles were ejected in the liquid and even in the solid phase. Time-resolved images show the propagation of the shockwaves: external shockwaves propagate outward and decelerate, and internal shockwaves reflect back and forth between the gas contact surface and the sample surface. The internal shockwave is proposed to cause the ejection of liquid particles when the internal shockwave strikes the liquid molten layer. A simulation based on vapor plume expansion was carried out and provides satisfactory agreement with experimental results. Different material properties result in different particle ejection behavior:particle ejection for most materials including metals result in a conically shaped envelope for the ejected material while ejection for silicon resembles a liquid jet. The difference in density change when the materials melt was proposed to be an important factor in the different ejection behavior. The characteristics of particles generated by laser ablation have a strong influence on the chemical analysis of the irradiated sample. Large particles are more difficult to completely vaporize and ionize, and induced preferential vaporization causes fractionation (i.e. a detected chemical composition that differs from the sample material). Large particles also result in spikes in

  6. Application of Advanced Laser Diagnostics to High-Impact Technologies: Science and Applications of Ultrafast, Ultraintense Lasers

    Science.gov (United States)

    2013-11-01

    only bremsstrahlung emissions in the hard X-ray range, thus allowing different K and L line emissions to be obtained by dissolving salts , etc., into...ray pulse emission from cesium chloride aqueous solutions when irradiated by double-pulsed femtosecond laser pulses,” Applied Physics Letters 93(6...pulses. These high power lasers can eject a molten spray of material resulting in recast on the surface so steps may have to be taken to minimize the

  7. Application of digital PWM technology in current transducers

    International Nuclear Information System (INIS)

    Liu Huifang; Hu Zhimin; Li Rui

    2012-01-01

    With the development of DSP technology and mature use of PID technology,, a new program for DC or AC signal measurement is proposed. Combined with the DSP chip timer module and PID algorithm, PWM signals are generated to control the feedback circuit for the compensation current. Finally the measured current value can be obtained according to the ampere-turns compensation current and the measured current. Studies have shown that this technology enables new current transducers have high stability. (authors)

  8. Laser In Veterinary Medicine

    Science.gov (United States)

    Newman, Carlton; Jaggar, David H.

    1982-12-01

    Lasers have been used for some time now on animals for experimental purposes prior to their use in human medical and surgical fields. However the use of lasers in veterinary medicine and surgery per se is a recent development. We describe the application of high and low intensity laser technology in a general overview of the current uses, some limitations to its use and future needs for future inquiry and development.

  9. Laser induced breakdown spectroscopy for applications in nuclear industry

    International Nuclear Information System (INIS)

    Suri, B.M.

    2010-01-01

    There are several analytical techniques employing laser spectroscopy - each with its own distinctive potential. Laser Induced Breakdown Spectroscopy (LIBS) is one such technique which is attractive in view of its relative compactness and simplicity (in configuration), remote and online analysis (with no sample handling requirement) and high spatial resolution allowing compositional map or homogeneity analysis. In this technique, a high power pulsed (mostly nanosecond) laser is employed to irradiate the sample causing spark emission, characteristics of the sample composition, which is collected using suitable optics and analysed spectroscopically. Remote and online capability is derived from long distance delivery of laser beams and collection of emitted light by fibres or conventional optics. Since laser can be focused sharply on the target, it can facilitate compositional mapping. Beam Technology Development Group at BARC had initiated work on LIBS of nuclear materials several years ago. Recently the challenge of online monitoring of radioactive waste vitrification plant in a hot cell has been taken up. The theoretical and experimental work done by the group related to instrument development, plasma characterization, quantitative compositional analysis of ternary alloys and uranium vitrified glass samples (comprising more than dozen elements) are described. The future plans for setting up online glass homogeneity monitoring facility are also described. This should fulfill an important demand for optimization of vitrification process. Various other demands of nuclear industry are also reviewed

  10. Application of CO II laser for removal of oral mucocele

    Science.gov (United States)

    Kato, J.; Moriya, K.; Hirai, Y.

    2006-02-01

    Mucocele is an oral soft tissue cyst caused by the disturbance of saliva flow. Mucocele is widely observed in child patients and recurrence is high. The objective of this study was to clarify the effect of CO II laser irradiation in the case of mucocele. A CO II laser was used on 45 subjects, aged between 0 to 15 years, having mucocele on lip, lingual, or buccal mucosa. Our procedure in using CO II laser was not to vaporize the mucocele but to remove the whole mucocele mass. The border of mucocele was firstly incised by laser following defocusly ablating the root or body of mucocele separating from sorrounding tissue. As a result, mucocele was easily and completely removed without breaking the wall of mucocele. None of the cases required suturing. The results were as follows. 1. The mucocele of lip or lingual mucosa with a rich blood supply, was efficiently removed, without bleeding, giving a clear operative field during the operation. 2. The surgery itself was simple and less time-consuming. 3. After two or three weeks the wound was completely healed without almost any discomfort in all patients 4. Wound contraction and scarring were decreased or eliminated. 5. The reoccurrence of mucocele was not seen, except only in one case of lingual mucocele. In conclusion the use of CO II laser proved to be a very safe and effective mode for the removal of mucocele, especially in small children.

  11. Application Of Endoscopic Lasers For Operations In Gastro-Intestinal Tract

    Science.gov (United States)

    Skobelkin, O. K.; Saphronov, A. M.; Shapovalov, A. M.; Zaharov, P. I.

    1988-06-01

    We have described our experience in the application of high energy argon and Nd:YAG lasers for endoscopic surgical manipulations. Laser was used for the removal of polyps with a wide base, villi tumours in colon, for the elimination of scar strictures in colon anastomosis, for the formation of primary-delayed colon anastomosis and for the removal of timoral stenosis in esophagus and in colon. Laser therapy has certain advantages over other endoscopic manipulations: long-term and immediate results are better. One can use this therapy in combination with others (radial therapy, surgical treatment). We have worked out a classification of polyps and stenosing tumours in the digestive system to determine indications for laser endoscopy and to choose the best parameters of laser irradiation.

  12. Coilable single crystal fibers of doped-YAG for high power laser applications

    Science.gov (United States)

    Maxwell, Gisele; Soleimani, Nazila; Ponting, Bennett; Gebremichael, Eminet

    2013-05-01

    Single crystal fibers are an intermediate between laser crystals and doped glass fibers. They can combine the advantages of both by guiding laser light and matching the efficiencies found in bulk crystals, making them ideal candidates for high-power laser and fiber laser applications. In particular, a very interesting feature of single crystal fiber is that they can generate high power in the eye-safe range (Er:YAG) with a high efficiency, opening new possibilities for portable directed energy weapons. This work focuses on the growth of a flexible fiber with a core of dopant (Er, Nd, Yb, etc…) that will exhibit good waveguiding properties. Direct growth or a combination of growth and cladding experiments are described. We have, to date, demonstrated the growth of a flexible foot long 45 microns doped YAG fiber. Scattering loss measurements at visible wavelengths along with dopant profile characterization are also presented. Laser characterization for these fibers is in progress.

  13. Design and performance of a sealed CO2 laser for industrial applications

    International Nuclear Information System (INIS)

    Botero, G; Gomez, D; Nisperuza, D; Bastidas, A

    2011-01-01

    A large amount of materials processing is done using an industrial CO 2 laser operating in the mid-infrared (IR) spectrum. Their high efficiency and tremendous power output have made them one of the most commonly known transition wavelength at 10,6 microns facilitates laser cutting, drilling and marking of a wide variety of materials in the electronics and medical industries. Because lasers are feedback systems, many of their design parameters strongly interact with one another, and arriving at an optimum design requires a really thorough understanding of just how they interact. We report the construction of a sealed CO2 gas discharge laser with a glass laser tube design as well as clear acrylic housing makes this an excellent demonstrational tool. Sealed operation was characterized in mode, power, warm-up and stability over a long time. The results indicate a good operation, optimum wavelength, powers and beam quality will remove material more efficiently in effective industrial applications.

  14. Single-mode interband cascade laser sources for mid-infrared spectroscopic applications

    Science.gov (United States)

    Scheuermann, J.; von Edlinger, M.; Weih, R.; Becker, S.; Nähle, L.; Fischer, M.; Koeth, J.; Kamp, M.; Höfling, S.

    2016-05-01

    Compared to the near infrared, many technologically and industrially relevant gas species have more than an order of magnitude higher absorption features in the mid-infrared (MIR) wavelength range. These species include for example important hydrocarbons (methane, acetylene), nitrogen oxides and sulfur oxides. Tunable laser absorption spectroscopy (TLAS) has proven to be a versatile tool for gas sensing applications with significant advantages compared to other techniques. These advantages include real time measurement, standoff detection and ruggedness of the sensor. We present interband cascade lasers (ICLs), which have evolved into important laser sources for the MIR spectral range from 3 to 7 μm. ICLs achieve high efficiency by cascading optically active zones whilst using interband transitions, so they combine common diode laser as well as quantum cascade laser based technologies. Our application grade singlemode distributed feedback devices operate continuous wave at room temperature and are offering several features especially useful for high performance TLAS applications like: side mode suppression ratio of > 30 dB, continuous tuning ranges up to 30 nm, low threshold power densities and low overall power consumption. The devices are typically integrated in a thermoelectrically cooled TO-style package, hermetically sealed using a cap with anti-reflection coated window. This low power consumption as well as the compact size and ruggedness of the fabricated laser sources makes them perfectly suited for battery powered portable solutions for in field spectroscopy applications.

  15. Continuous and pulsed laser high power beam combiner for additive manufacturing applications

    Science.gov (United States)

    Bassignana, Marta; Califano, Alessio; Pescarmona, Francesco; Braglia, Andrea; Perrone, Guido

    2018-02-01

    Laser-based additive manufacturing (AM) from metal powders is emerging as the new industrial revolution, although current fabrication approaches still require long mechanical post-processing to improve the final surface quality and meet the design tolerances. To overcome this limitation, the next generation machines are expected to complement laser AM with laser ablation (LA) to implement surface finishing and micro texturing already during the device growth process. With this aim, a new beam combiner to allow the real-time interchange of additive and subtractive processes using the same scanner head has been designed. Extensive tests have been carried out using a 6 kW continuous-wave laser similar to that used for the metal powder fusion and a nanosecond 100W pulsed source similar to that used for laser ablation.

  16. Clinical applications of in vivo fluorescence confocal laser scanning microscopy

    Science.gov (United States)

    Oh, Chilhwan; Park, Sangyong; Kim, Junhyung; Ha, Seunghan; Park, Gyuman; Lee, Gunwoo; Lee, Onseok; Chun, Byungseon; Gweon, Daegab

    2008-02-01

    Living skin for basic and clinical research can be evaluated by Confocal Laser Scanning Microscope (CLSM) non-invasively. CLSM imaging system can achieve skin image its native state either "in vivo" or "fresh biopsy (ex vivo)" without fixation, sectioning and staining that is necessary for routine histology. This study examines the potential fluorescent CLSM with a various exogenous fluorescent contrast agent, to provide with more resolution images in skin. In addition, in vivo fluorescent CLSM researchers will be extended a range of potential clinical application. The prototype of our CLSM system has been developed by Prof. Gweon's group. The operating parameters are composed of some units, such as illuminated wavelength 488 nm, argon illumination power up to 20mW on the skin, objective lens, 0.9NA oil immersion, axial resolution 1.0μm, field of view 200μm x 100μm (lateral resolution , 0.3μm). In human volunteer, fluorescein sodium was administrated topically and intradermally. Animal studies were done in GFP transgenic mouse, IRC mouse and pig skin. For imaging of animal skin, fluorescein sodium, acridine orange, and curcumine were used for fluorescein contrast agent. We also used the GFP transgenic mouse for fluorescein CLSM imaging. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. Curcumin is a yellow food dye that has similar fluorescent properties to fluorescein sodium. Acridin Orange can be highlight nuclei in viable keratinocyte. In vivo CLSM of transgenic GFP mouse enable on in vivo, high resolution view of GFP expressing skin tissue. GFP signals are brightest in corneocyte, kertinocyte, hair and eccrine gland. In intact skin, absorption of fluorescein sodium by individual corneocyte and hair. Intradermal administrated the fluorescein sodium, distinct outline of keratinocyte cell border could be seen. In

  17. Degradation mechanisms in high-power multi-mode InGaAs-AlGaAs strained quantum well lasers for high-reliability applications

    Science.gov (United States)

    Sin, Yongkun; Presser, Nathan; Brodie, Miles; Lingley, Zachary; Foran, Brendan; Moss, Steven C.

    2015-03-01

    Laser diode manufacturers perform accelerated multi-cell lifetests to estimate lifetimes of lasers using an empirical model. Since state-of-the-art laser diodes typically require a long period of latency before they degrade, significant amount of stress is applied to the lasers to generate failures in relatively short test durations. A drawback of this approach is the lack of mean-time-to-failure data under intermediate and low stress conditions, leading to uncertainty in model parameters (especially optical power and current exponent) and potential overestimation of lifetimes at usage conditions. This approach is a concern especially for satellite communication systems where high reliability is required of lasers for long-term duration in the space environment. A number of groups have studied reliability and degradation processes in GaAs-based lasers, but none of these studies have yielded a reliability model based on the physics of failure. The lack of such a model is also a concern for space applications where complete understanding of degradation mechanisms is necessary. Our present study addresses the aforementioned issues by performing long-term lifetests under low stress conditions followed by failure mode analysis (FMA) and physics of failure investigation. We performed low-stress lifetests on both MBE- and MOCVD-grown broad-area InGaAs- AlGaAs strained QW lasers under ACC (automatic current control) mode to study low-stress degradation mechanisms. Our lifetests have accumulated over 36,000 test hours and FMA is performed on failures using our angle polishing technique followed by EL. This technique allows us to identify failure types by observing dark line defects through a window introduced in backside metal contacts. We also investigated degradation mechanisms in MOCVD-grown broad-area InGaAs-AlGaAs strained QW lasers using various FMA techniques. Since it is a challenge to control defect densities during the growth of laser structures, we chose to

  18. ELIMED, future hadrontherapy applications of laser-accelerated beams

    Czech Academy of Sciences Publication Activity Database

    Cirrone, Giuseppe A.P.; Carpinelli, M.; Cuttone, G.; Gammino, S.; Jia, S.B.; Korn, Georg; Maggiore, Mario; Manti, L.; Margarone, Daniele; Prokůpek, Jan; Renis, M.; Romano, F.; Schillaci, Francesco; Tomasello, B.; Torrisi, L.; Tramontana, A.; Velyhan, Andriy

    2013-01-01

    Roč. 730, Dec (2013), s. 174-177 ISSN 0168-9002. [International Conference on Radiation Effects on Semiconductor Materials, Detectors and Devices /9./(RESMDD). Florence, 09.10.2012-12.10.2012] R&D Projects: GA ČR(CZ) GAP205/11/1165; GA MŠk ED1.1.00/02.0061; GA MŠk EE.2.3.20.0087 Grant - others:ELI Beamlines(XE) CZ.1.05/1.1.00/02.0061; OP VK 2 LaserGen(XE) CZ.1.07/2.3.00/20.0087 Institutional support: RVO:68378271 Keywords : laser acceleration * cancer treatment * particle selection * Monte Carlo simulation * beam handling Subject RIV: BH - Optics, Masers, Lasers Impact factor: 1.316, year: 2013

  19. Solid-state ring laser gyro for aerospace applications

    Science.gov (United States)

    Schwartz, Sylvain; Gutty, François; Feugnet, Gilles; Pocholle, Jean-Paul; Desilles, Gaël.

    2017-11-01

    We report on the development of a prototype solidstate ring laser gyro based on a diode-pumped neodymium-doped yttrium aluminum garnet crystal as the gain medium. We describe in this paper how we circumvent mode competition between the counter-propagating modes using a feedback loop acting on the differential losses. We then show how the non-linear frequency response can be significantly improved by vibrating the gain medium along the laser axis, leading to a behavior similar as a typical Helium-Neon ring laser gyro. We finally discuss the undergoing improvements for achieving high inertial performance with this device, with significant potential benefits in terms of cost and robustness as compared to other highperformance gyro technologies.

  20. Calibration technology in application of robot-laser scanning system

    Science.gov (United States)

    Ren, YongJie; Yin, ShiBin; Zhu, JiGui

    2012-11-01

    A system composed of laser sensor and 6-DOF industrial robot is proposed to obtain complete three-dimensional (3-D) information of the object surface. Suitable for the different combining ways of laser sensor and robot, a new method to calibrate the position and pose between sensor and robot is presented. By using a standard sphere with known radius as a reference tool, the rotation and translation matrices between the laser sensor and robot are computed, respectively in two steps, so that many unstable factors introduced in conventional optimization methods can be avoided. The experimental results show that the accuracy of the proposed calibration method can be achieved up to 0.062 mm. The calibration method is also implemented into the automated robot scanning system to reconstruct a car door panel.