WorldWideScience

Sample records for laser angioplasty system

  1. CO laser angioplasty system: efficacy of manipulatable laser angioscope catheter

    Science.gov (United States)

    Arai, Tsunenori; Kikuchi, Makoto; Mizuno, Kyoichi; Sakurada, Masami; Miyamoto, Akira; Arakawa, Koh; Kurita, Akira; Nakamura, Haruo; Takeuchi, Kiyoshi; Utsumi, Atsushi; Akai, Yoshiro

    1992-08-01

    A percutaneous transluminal coronary angioplasty system using a unique combination of CO laser (5 micrometers ) and As-S infrared glass fiber under the guidance of a manipulatable laser angioscope catheter is described. The ablation and guidance functions of this system are evaluated. The angioplasty treatment procedure under angioscope guidance was studied by in vitro model experiment and in vivo animal experiment. The whole angioplasty system is newly developed. That is, a transportable compact medical CO laser device which can emit up to 10 W, a 5 F manipulatable laser angioscope catheter, a thin CO laser cable of which the diameter is 0.6 mm, an angioscope imaging system for laser ablation guidance, and a system controller were developed. Anesthetized adult mongrel dogs (n equals 5) with an artificial complete occlusion in the femoral artery and an artificial human vessel model including occluded or stenotic coronary artery were used. The manipulatability of the catheter was drastically improved (both rotation and bending), therefore, precise control of ablation to expand stenosis was obtained. A 90% artificial stenosis made of human yellow plaque in 4.0 mm diameter in the vessel was expanded to 70% stenosis by repetitive CO laser ablations of which total energy was 220 J. All procedures were performed and controlled under angioscope visualization.

  2. State of the art of CO laser angioplasty system

    Science.gov (United States)

    Arai, Tsunenori; Mizuno, Kyoichi; Miyamoto, Akira; Sakurada, Masami; Kikuchi, Makoto; Kurita, Akira; Nakamura, Haruo; Takaoka, Hidetsugu; Utsumi, Atsushi; Takeuchi, Kiyoshi

    1994-07-01

    A unique percutaneous transluminal coronary angioplasty system new IR therapy laser with IR glass fiber delivery under novel angioscope guidance was described. Carbon monoxide (CO) laser emission of 5 mm in wavelength was employed as therapy laser to achieve precise ablation of atheromatous plaque with a flexible As-S IR glass fiber for laser delivery. We developed the first medical CO laser as well as As-S IR glass fiber cable. We also developed 5.5 Fr. thin angioscope catheter with complete directional manipulatability at its tip. The system control unit could manage to prevent failure irradiations and fiber damages. This novel angioplasty system was evaluated by a stenosis model of mongrel dogs. We demonstrated the usefulness of our system to overcome current issues on laser angioplasty using multifiber catheter with over-the-guidewire system.

  3. Transluminal laser angioplasty

    Science.gov (United States)

    Otto, Wlodzimierz

    1996-03-01

    Twenty seven patients with femoral artery occlusion were treated by transluminal Nd:YAG laser angioplasty, in 16 patients the procedure was combined with intraarterial infusion of rTPA (actilyse-Boehringer Ing). In 5 out of 11 patients from the initial group recanalization was not successful. In 16 patients from the rTPA group satisfactory immediate results were achieved in all cases. In long time observations ranging from 9 to 24 months all patients remained free from symptoms, although in 4 of them angiography and Doppler ultrasound examination reveal no flow in the femoral artery. In the remaining 12 patients (75%), the previously occluded artery is patent. No complications of laser angioplasty nor intraarterial infusion of rTPA were noted in this series.

  4. [Coronary transluminal angioplasty and determination of the intracoronary gradient with a new monorail system].

    Science.gov (United States)

    Freitas, A D; Medina, A; Bethencourt, A; Coello, I; Hernández, E; Peraza, C; Melian, F; Jiménez, F; Laraudogoitia, E; Goicolea, J

    1989-10-01

    To evaluate the results obtained in coronary angioplasty using the new very low profile monorail catheter. A retrospective study to define the causes and frequency of successful and unsuccessful coronary angioplasty on proximal and distal lesions located in the three coronary vessels. Patients referred to the Hemodynamic Unit for coronary angioplasty. Coronary angioplasty was performed in 106 patients with cardiac ischemic disease (stable angina, unstable angina and myocardial infarction after thrombolytic therapy). To perform coronary angioplasty using a monorail system, including dilatation of vessels (angioplasty) and to measure the intracoronary gradient. A high success rate was achieved (92%) independent of vessel dilated or of the position of the stenosis. There was a lower success rate in complex lesions. In this study, this newly modified system for coronary angioplasty with balloon catheter and monorail pressure catheter gave a very high performance.

  5. Application of conjugated heparin-albumin microparticles with laser-balloon angioplasty: a potential method for reducing adverse biologic reactivity after angioplasty

    Science.gov (United States)

    Kundu, Sourav K.; McMath, Linda P.; Zaidan, Jonathan T.; Spears, J. Richard

    1991-05-01

    Laser-balloon angioplasty (LBA) may potentially be used for local application of pharmacologically active agents which will reduce thrombogenic and proliferative responses after the angioplasty. In this study, the feasibility of applying covalently conjugated heparin- albumin microparticles onto arterial luminal surface was demonstrated. The covalent linkages were formed by reaction with 1-ethyl-3-dimethyl-aminopropyl-carbodiimide (EDC), and the resultant conjugates were used for preparation of microparticles by employing standard emulsification and heat-crosslinking techniques. The heparin release rate from the microparticles was found to be dependent upon the degree of crosslinking. When a thin coagulum of a suspension of microparticles was formed with heat on a glass surface, the treated surface demonstrated resistance to clot formation in contact with non-anticoagulated blood. A suspension of the microparticles applied during laser-balloon angioplasty onto the luminal surface of dog carotid and femoral arteries showed persistence for up to one week without thrombus formation or occlusion of the vessel. Since the rate of biodegradation is primarily dictated by the extent of crosslinking, an optimal degree of thermal denaturation will permit longer persistence of the carrier while allowing adequate release of the entrapped pharmacologic agent. A variety of antithrombotic and antiinflammatory agents are being considered as candidate bioprotective materials for local application after angioplasty.

  6. Cool excimer laser-assisted angioplasty (CELA) and tibial balloon angioplasty (TBA) in management of infragenicular arterial occlusion in critical lower limb ischemia (CLI).

    Science.gov (United States)

    Sultan, Sherif; Tawfick, Wael; Hynes, Niamh

    2013-04-01

    We aim to compare cool excimer laser-assisted angioplasty (CELA) versus tibial balloon angioplasty (TBA) in patients with critical limb ischemia (CLI) with tibial artery occlusive disease. The primary end point is sustained clinical improvement (SCI) and amputation-free survival (AFS). The secondary end points are binary restenosis, target extremity revascularization (TER), and cost-effectiveness. From June 2005 to October 2010, 1506 patients were referred with peripheral vascular disease and 572 with CLI. A total of 80 patients underwent 89 endovascular revascularizations (EVRs) for tibial occlusions, 47 using TBA and 42 using CELA. All patients were Rutherford category 4 to 6. Three-year SCI was enhanced with CELA (81%) compared to TBA (63.8%; P = .013). Three-year AFS significantly improved with CELA (95.2%) versus TBA (89.4%; P = .0165). Three-year freedom from TER was significantly improved with CELA (92.9%) versus 78.7% TBA (P = .026). Three-year freedom from MACE was comparable in both the groups (P = .455). Patients with CELA had significantly improved quality time without symptoms of disease or toxicity of treatment (Q-TWiST) at 3 years (10.5 months; P = .048) with incremental cost of €2073.19 per quality-adjusted life year gained. Tibial EVR provides exceptional outcome in CLI. The CELA has superior SCI, AFS, and freedom from TER, with improved Q-TWiST and cost-effectiveness.

  7. [Coronary angioplasty with the Monorail system via 6 French diagnostic catheters].

    Science.gov (United States)

    Villavicencio, R; González, H; López, J; Zavala, E; Ban Hayashi, E B; Gaspar, J; Gil, M; Martínez Ríos, M A

    1994-01-01

    We studied the use of "Monorail" system with Express (Scimed) balloon catheters for coronary angioplasty through 6 French (F) "high-flow" diagnostic catheters (Novoste, USCI). Prospectively, from July 1992 to January 1993, angioplasty of 31 lesions in 24 patients was attempted (1.3 lesions/procedure). Twenty procedures were of a single lesion and four were multi-vessel angioplasty. Fourteen lesions were in the left anterior descending or in its branches, 10 in the left circumflex or in its branches, 6 in the right coronary artery, and one in the distal anastomosis of an internal mammary artery graft. Thirteen lesions (42%) were type A, 17 (55%) type B and one (3%) type C. Balloon sizes varied between 2.0 and 3.5 mm. Twenty-nine lesions could be successfully dilated (93.5%); two cases were unsuccessful due to an acute occlusion in one and residual stenosis of more than 50% in the other. For only one case, another balloon catheter different from the "Monorail" system was necessary to complete a multi-vessel angioplasty. Coronary visualization and manipulation of the balloon through the tip of the diagnostic catheter were satisfactory in all cases, except with the 3.5 mm balloon catheter. Coronary angioplasty with "Monorail" system balloon catheters through 6 F "high-flow" diagnostic catheters is feasible and provides a high success rate in simple and moderately complex selected lesions, including multivessel angioplasty with advantages of smaller artery punction and the feasibility of performing coronary angioplasty with the same catheter used for diagnostic angiography.

  8. Restenosis after hot-tip laser-balloon angioplasty: histologic evaluation of the samples removed by Simpson atherectomy

    Science.gov (United States)

    Barbieri, Enrico; Tanganelli, Pietro; Taddei, Giuseppe; Perbellini, Antonio; Attino, Vito; Destro, Gianni; Zardini, Piero

    1991-05-01

    Laser balloon angioplasty has been used in recent years to treat peripheral artery disease. Despite a primary success the technique is plagued by a high restenosis rate. Directional atherectomy was performed in a small group of patients affected by primitive stenosis or restenosis after an invasive procedure. Light microscopy, immunohistochemistry, and transmission electron microscopy have identified the cellular component of intimal hyperplasia as smooth muscle cells in an active synthetic phenotype. The arterial healing process after invasive procedures seems to develop similarly independently of the device employed.

  9. Early outcome of high energy Laser (Excimer) facilitated coronary angioplasty ON hARD and complex calcified and balloOn-resistant coronary lesions: LEONARDO Study

    International Nuclear Information System (INIS)

    Ambrosini, Vittorio; Sorropago, Giovanni; Laurenzano, Eugenio; Golino, Luca; Casafina, Alfredo; Schiano, Vittorio; Gabrielli, Gabriele; Ettori, Federica; Chizzola, Giuliano; Bernardi, Guglielmo; Spedicato, Leonardo; Armigliato, Pietro; Spampanato, Carmine; Furegato, Martina

    2015-01-01

    Aim: An innovative xenon–chlorine (excimer) pulsed laser catheter (ELCA X80) has been recently used for the treatment of complex coronary lesions, as calcified stenosis, chronic total occlusions and non-compliant plaques. Such complex lesions are difficult to adequately treat with balloon angioplasty and/or intracoronary stenting. The aim of this study was to examine the acute outcome of this approach on a cohort of patients with coronary lesions. Methods and Results: Eighty patients with 100 lesions were enrolled through four centers, and excimer laser coronary angioplasty was performed on 96 lesions (96%). Safety and effectiveness data were compared between patients treated with standard laser therapy and those treated with increased laser therapy. Laser success was obtained in 90 lesions (93.7%), procedural success was reached in 88 lesions (91.7%), and clinical success in was obtained in 87 lesions (90.6%). There was no perforation, major side branch occlusion, spasm, no-reflow phenomenon, dissection nor acute vessel closure. Increased laser parameters were used successfully for 49 resistant lesions without complications. Conclusions: This study suggests that laser-facilitated coronary angioplasty is a simple, safe and effective device for the management of complex coronary lesions. Furthermore, higher laser energy levels delivered by this catheter improved the device performance without increasing complications. - Highlights: • We planned this multicenter study to examine the acute outcome of an innovative xenon–chlorine (excimer) pulsed laser catheter (ELCA X80) for treatment of complex coronary lesions. • We enrolled 80 patients with 100 lesions and performed excimer laser coronary angioplasty in 96 lesions (96%). • Laser success was obtained in 90 lesions (93.7%), procedural success was reached in 88 lesions (91.7%), and clinical success was obtained in 87 lesions (90.6%). • Increased laser parameters were used successfully for 49 resistant

  10. Early outcome of high energy Laser (Excimer) facilitated coronary angioplasty ON hARD and complex calcified and balloOn-resistant coronary lesions: LEONARDO Study

    Energy Technology Data Exchange (ETDEWEB)

    Ambrosini, Vittorio; Sorropago, Giovanni; Laurenzano, Eugenio [Montevergine Clinic, Mercogliano (Italy); Golino, Luca, E-mail: lucagolino.jazz@alice.it [Montevergine Clinic, Mercogliano (Italy); Moriggia-Pelascini Hospital, Gravedona, Como (Italy); Casafina, Alfredo; Schiano, Vittorio [Montevergine Clinic, Mercogliano (Italy); Gabrielli, Gabriele [University Hospital Ospedali Riuniti, Ancona (Italy); Ettori, Federica; Chizzola, Giuliano [Spedali Civili University Hospital, Brescia (Italy); Bernardi, Guglielmo; Spedicato, Leonardo [University Hospital S. Maria Misericordia, Udine (Italy); Armigliato, Pietro [Istituto Italiano Ricerche Mediche, Verona (Italy); Spampanato, Carmine [Telethon Institute of Genetics and Medicine (TIGEM), Naples (Italy); Furegato, Martina [Istituto Italiano Ricerche Mediche, Verona (Italy)

    2015-04-15

    Aim: An innovative xenon–chlorine (excimer) pulsed laser catheter (ELCA X80) has been recently used for the treatment of complex coronary lesions, as calcified stenosis, chronic total occlusions and non-compliant plaques. Such complex lesions are difficult to adequately treat with balloon angioplasty and/or intracoronary stenting. The aim of this study was to examine the acute outcome of this approach on a cohort of patients with coronary lesions. Methods and Results: Eighty patients with 100 lesions were enrolled through four centers, and excimer laser coronary angioplasty was performed on 96 lesions (96%). Safety and effectiveness data were compared between patients treated with standard laser therapy and those treated with increased laser therapy. Laser success was obtained in 90 lesions (93.7%), procedural success was reached in 88 lesions (91.7%), and clinical success in was obtained in 87 lesions (90.6%). There was no perforation, major side branch occlusion, spasm, no-reflow phenomenon, dissection nor acute vessel closure. Increased laser parameters were used successfully for 49 resistant lesions without complications. Conclusions: This study suggests that laser-facilitated coronary angioplasty is a simple, safe and effective device for the management of complex coronary lesions. Furthermore, higher laser energy levels delivered by this catheter improved the device performance without increasing complications. - Highlights: • We planned this multicenter study to examine the acute outcome of an innovative xenon–chlorine (excimer) pulsed laser catheter (ELCA X80) for treatment of complex coronary lesions. • We enrolled 80 patients with 100 lesions and performed excimer laser coronary angioplasty in 96 lesions (96%). • Laser success was obtained in 90 lesions (93.7%), procedural success was reached in 88 lesions (91.7%), and clinical success was obtained in 87 lesions (90.6%). • Increased laser parameters were used successfully for 49 resistant

  11. Laser-driven short-duration heating angioplasty: dilatation performance in cadaver atherosclerotic femoral arteries

    Science.gov (United States)

    Shimazaki, Natsumi; Naruse, Sho; Arai, Tsunenori; Imanishi, Nobuaki; Aiso, Sadakazu

    2013-03-01

    The purpose of this study was to investigate the artery dilatation performance of the short-duration heating balloon catheter in cadaver stenotic arteries. We designed a prototype short-duration heating balloon catheter that can heat artery media to around 60 °C in 15-25 s by a combination of laser-driven heat generation and continuous fluid irrigation in the balloon. We performed ex vivo short-duration heating dilatation in the cadaver atherosclerotic femoral arteries (initial percent diameter stenosis was 36-98%), with the maximum balloon temperature of 65+/-5 °C, laser irradiation duration of 25 s, and balloon dilatation pressure of 3.5 atm. The artery lumen configurations before and after the dilatations were assessed with a commercial IVUS system. After the short-duration heating dilatations, the percent diameter stenosis was reduced below 30% without any artery tears or dissections. We estimated that the artery media temperature was raised to around 60 °C in which plaque thickness was below 0.8 mm by a thermal conduction calculation. The estimated maximum temperature in artery adventitia and surrounding tissue was up to 45 °C. We found that the short-duration heating balloon could sufficiently dilate the cadaver stenotic arteries, without thermal injury in artery adventitia and surroundings.

  12. Differential effects of Nd-YAG laser on collagen and elastin production by chick embryo aortae in vitro. Relevance to laser angioplasty for removal of atherosclerotic plaques

    International Nuclear Information System (INIS)

    Abergel, R.P.; Zaragoza, E.J.; Dwyer, R.M.; Uitto, J.

    1985-01-01

    Aortae from 17-day old chick embryos were subjected to irradiation with a Nd:YAG laser at energy densities varying from 1.2 - 4.7 X 10(3) J/cm2. The aortae were pulse-labeled in vitro with [ 3 H]proline or [ 14 C]valine, and the synthesis of collagenous polypeptides and soluble elastin was examined by SDS-polyacrylamide gel electrophoresis, followed by fluorography and quantitative scanning densitometry. Irradiation of the aortae with Nd:YAG laser resulted in inhibition of the synthesis of the extracellular matrix proteins. The production of collagen was inhibited to a considerably larger degree than the production of elastin. Thus, the biosynthetic pathway for collagen production appears to be more susceptible to laser inhibition than the corresponding pathway for elastin production. These observations may have relevance to laser angioplasty which has been proposed to be applicable for removal of atherosclerotic plaques in human vessels. Specifically, the results suggest that inhibition of the extracellular matrix production may result in weakening of the vessel wall with subsequent aneurysm formation and rupture

  13. High power lasers & systems

    OpenAIRE

    Chatwin, Chris; Young, Rupert; Birch, Philip

    2015-01-01

    Some laser history;\\ud Airborne Laser Testbed & Chemical Oxygen Iodine Laser (COIL);\\ud Laser modes and beam propagation;\\ud Fibre lasers and applications;\\ud US Navy Laser system – NRL 33kW fibre laser;\\ud Lockheed Martin 30kW fibre laser;\\ud Conclusions

  14. Angioplasty and stent - heart - discharge

    Science.gov (United States)

    Drug-eluting stents - discharge; PCI - discharge; Percutaneous coronary intervention - discharge; Balloon angioplasty - discharge; Coronary angioplasty - discharge; Coronary artery angioplasty - discharge; Cardiac ...

  15. Differences in optical coherence tomographic findings and clinical outcomes between excimer laser and cutting balloon angioplasty for focal in-stent restenosis lesions.

    Science.gov (United States)

    Nishino, Masami; Lee, Yasuharu; Nakamura, Daisuke; Yoshimura, Takahiro; Taniike, Masayuki; Makino, Nobuhiko; Kato, Hiroyasu; Egami, Yasuyuki; Shutta, Ryu; Tanouchi, Jun; Yamada, Yoshio

    2012-10-01

    In-stent restenosis (ISR), especially focal ISR, after percutaneous coronary intervention (PCI) remains one of the major clinical problems in the drug-eluting stent (DES) era. Several reports have revealed that excimer laser coronary angioplasty (ELCA) is useful for ISR; however, detailed findings after ELCA are unknown. Therefore, we investigated the condition of the neointima after ELCA for ISR with optical coherence tomography (OCT) and compared the OCT findings and clinical outcome between ELCA and cutting-balloon angioplasty (CBA). Twenty-one consecutive patients with focal ISR who underwent ELCA or CBA were enrolled. All patients underwent 12- to 15-month follow-up coronary angiography. OCT was performed immediately after successful PCI to evaluate the neointimal condition in the ISR lesion. We compared the following OCT parameters between ELCA and CBA groups: maximal thickness of remaining in-stent neointima (MTN), number of tears, minimum lumen dimension (MLD), and minimum lumen area (MLA). We also evaluated clinical outcomes, including target vessel revascularization, acute myocardial infarction, death, and stent thrombosis. MLA in the ELCA group (n = 10) was significantly larger than in the CBA group, and number of tears in the ELCA group was significantly lower than in the CBA group. A trend was shown toward lower TLR with ELCA versus CBA (10.0% vs 45.5%). OCT immediately after ELCA for ISR lesions revealed larger lumen area and smaller number of tears compared with CBA, which may support favorable effects of ELCA for focal ISR.

  16. Functional Angioplasty

    Directory of Open Access Journals (Sweden)

    Rohit Tewari

    2013-01-01

    Full Text Available Coronary angiography underestimates or overestimates lesion severity, but still remains the cornerstone in the decision making for revascularization for an overwhelming majority of interventional cardiologists. Guidelines recommend and endorse non invasive functional evaluation ought to precede revascularization. In real world practice, this is adopted in less than 50% of patients who go on to have some form of revascularization. Fractional flow reserve (FFR is the ratio of maximal blood flow in a stenotic coronary relative to maximal flow in the same vessel, were it normal. Being independent of changes in heart rate, BP or prior infarction; and take into account the contribution of collateral blood flow. It is a majorly specific index with a reasonably high sensitivity (88%, specificity (100%, positive predictive value (100%, and overall accuracy (93%. Whilst FFR provides objective determination of ischemia and helps select appropriate candidates for revascularization (for both CABG and PCI in to cath lab itself before intervention, whereas intravascular ultrasound/optical coherence tomography guidance in PCI can secure the procedure by optimizing stent expansion. Functional angioplasty simply is incorporating both intravascular ultrasound and FFR into our daily Intervention practices.

  17. Carotid Angioplasty and Stenting

    Science.gov (United States)

    Carotid angioplasty and stenting Overview Carotid angioplasty (kuh-ROT-id AN-jee-o-plas-tee) and stenting ... to better see and examine the blood vessels. Food and medications You'll receive instructions on what ...

  18. Monorail Piccolino catheter: a new rapid exchange/ultralow profile coronary angioplasty system.

    Science.gov (United States)

    Mooney, M R; Douglas, J S; Mooney, J F; Madison, J D; Brandenburg, R O; Fernald, R; Van Tassel, R A

    1990-06-01

    The Monorail Piccolino coronary angioplasty balloon catheter (MBC) was evaluated on 118 patients at two centers. Technical success was achieved in 110 patients (93%). Time for catheter exchange and total fluoroscopy time were significantly lower for the Monorail catheter than with standard equipment (exchange time 97 vs. 170 seconds P less than .05 and fluoroscopy time 17 vs. 88 seconds P less than .001). The advantages of rapid exchange and the ability of utilize 2 Monorail balloon catheters through one 9F guiding catheter for simultaneous inflations allowed for maximal flexibility in treating patients with bifurcation lesions. The double wire approach utilizing one Monorail balloon catheter with a 7F guiding catheter was also technically successful. The Monorail Piccolino balloon catheter has unique features that allow for greater ease of operator use, rapid catheter exchange, and optimal angiographic visualization. It is felt that this catheter design provides distinct advantages over standard angioplasty equipment.

  19. [Coronary angioplasty simultaneous with the "kissing" technique in a bifurcation lesion: use of a guidewire, and 2 monorail systems of rapid interchange].

    Science.gov (United States)

    Escudero, X

    1996-01-01

    Coronary branch occlusion complicating percutaneous coronary angioplasty has been recognized in certain bifurcation lesions. The utilization of double angioplasty systems simultaneously has been called "kissing" because the image of contact between balloons, and has been utilized as an alternative to protect the jeopardized branch or prevent snowplow lesion of the principal artery. The technological advance with the use of wide lumen catheters and low profile dilation balloons make the application of this technique possible in those type of lesions using a single guiding catheter. The present paper describes one case treated with this technique using conventional angioplasty systems in a complex bifurcating lesion of the circumflex artery. Some technical considerations about the procedure are made.

  20. Laser cutting system

    Science.gov (United States)

    Dougherty, Thomas J

    2015-03-03

    A workpiece cutting apparatus includes a laser source, a first suction system, and a first finger configured to guide a workpiece as it moves past the laser source. The first finger includes a first end provided adjacent a point where a laser from the laser source cuts the workpiece, and the first end of the first finger includes an aperture in fluid communication with the first suction system.

  1. Infrared laser system

    International Nuclear Information System (INIS)

    Cantrell, C.D.; Carbone, R.J.

    1977-01-01

    An infrared laser system and method for isotope separation may comprise a molecular gas laser oscillator to produce a laser beam at a first wavelength, Raman spin flip means for shifting the laser to a second wavelength, a molecular gas laser amplifier to amplify said second wavelength laser beam to high power, and optical means for directing the second wavelength, high power laser beam against a desired isotope for selective excitation thereof in a mixture with other isotopes. The optical means may include a medium which shifts the second wavelength high power laser beam to a third wavelength, high power laser beam at a wavelength coincidental with a corresponding vibrational state of said isotope and which is different from vibrational states of other isotopes in the gas mixture

  2. Robot-laser system

    International Nuclear Information System (INIS)

    Akeel, H.A.

    1987-01-01

    A robot-laser system is described for providing a laser beam at a desired location, the system comprising: a laser beam source; a robot including a plurality of movable parts including a hollow robot arm having a central axis along which the laser source directs the laser beam; at least one mirror for reflecting the laser beam from the source to the desired location, the mirror being mounted within the robot arm to move therewith and relative thereto to about a transverse axis that extends angularly to the central axis of the robot arm; and an automatic programmable control system for automatically moving the mirror about the transverse axis relative to and in synchronization with movement of the robot arm to thereby direct the laser beam to the desired location as the arm is moved

  3. Laser transmitter system

    International Nuclear Information System (INIS)

    Dye, R.A.

    1975-01-01

    A laser transmitter system is disclosed which utilizes mechanical energy for generating an output pulse. The laser system includes a current developing device such as a piezoelectric crystal which charges a storage device such as a capacitor in response to a mechanical input signal. The capacitor is coupled to a switching device, such as a silicon controlled rectifier (SCR). The switching device is coupled to a laser transmitter such as a GaAs laser diode, which provides an output signal in response to the capacitor being discharged

  4. Comparison of Immediate and 2-Year Outcomes between Excimer Laser-Assisted Angioplasty with Spot Stent and Primary Stenting in Intermediate to Long Femoropopliteal Disease

    Directory of Open Access Journals (Sweden)

    Tien-Yu Wu

    2013-01-01

    Full Text Available Background. To compare the clinical outcomes between excimer laser-assisted angioplasty (ELA with spot stent (group A and primary stenting (group B in intermediate to long femoropopliteal disease. Methods. Outcomes of 105 patients totaling 119 legs treated with two different strategies were analyzed retrospectively in a prospectively maintained database. Results. Baseline characteristics were similar in both groups. Better angiographic results and lesser increase of serum C-reactive protein levels (0.60 ± 0.72 versus 2.98 ± 0.97 mg/dL, P<0.001 after the intervention were obtained in Group B. Group A had inferior 1-year outcomes due to higher rate of binary restenosis (67% versus 32%, P=0.001 and lower rate of primary patency (40% versus 58%, P=0.039. Rates of amputation-free survival, target vessel revascularization, assisted primary patency, and stent fracture at 24 months were similar in both groups (80% versus 82%, P=0.979, 65% versus 45%, P=0.11, 78% versus 80%, P=0.75 and 6.3% versus 6.8%, P=0.71, resp.. Conclusion. Greater vascular inflammation after ELA with spot stent resulted in earlier restenosis and inferior 1-year clinical outcomes than primary stenting. This benefit was lost in the primary stenting group at 2 years due to late catch-up restenosis. Active surveillance with prompt intervention was required to maintain the vessel patency.

  5. Shiva laser system performance

    International Nuclear Information System (INIS)

    Glaze, J.; Godwin, R.O.; Holzrichter, J.F.

    1978-01-01

    On November 18, 1977, after four years of experimentation, innovation, and construction, the Shiva High Energy Laser facility produced 10.2 kJ of focusable laser energy delivered in a 0.95 ns pulse. The Shiva laser, with its computer control system and delta amplifiers, demonstrated its versatility on May 18, 1978, when the first 20-beam target shot with delta amplifiers focused 26 TW on a target and produced a yield of 7.5 x 10 9 neutrons

  6. Powering laser diode systems

    CERN Document Server

    Trestman, Grigoriy A

    2017-01-01

    This Tutorial Text discusses the competent design and skilled use of laser diode drivers (LDDs) and power supplies (PSs) for the electrical components of laser diode systems. It is intended to help power-electronic design engineers during the initial design stages: the choice of the best PS topology, the calculation of parameters and components of the PS circuit, and the computer simulation of the circuit. Readers who use laser diode systems for research, production, and other purposes will also benefit. The book will help readers avoid errors when creating laser systems from ready-made blocks, as well as understand the nature of the "mystical failures" of laser diodes (and possibly prevent them).

  7. Laser Megajoule synchronization system

    International Nuclear Information System (INIS)

    Luttmann, M.; Pastor, J.F; Drouet, V.; Prat, M.; Raimbourg, J.; Adolf, A.

    2011-01-01

    This paper describes the synchronisation system under development on the Laser Megajoule (LMJ) in order to synchronize the laser quads on the target to better than 40 ps rms. Our architecture is based on a Timing System (TS) which delivers trigger signals with jitter down to 15 ps rms coupled with an ultra precision timing system with 5 ps rms jitter. In addition to TS, a sensor placed at the target chamber center measures the arrival times of the 3 omega nano joule laser pulses generated by front end shots. (authors)

  8. Systemic Hypertension and Transient Ischemic Attack in a 6-Year-Old Girl with Fibromuscular Dysplasia Treated with Percutaneous Angioplasty

    International Nuclear Information System (INIS)

    Foa-Torres, Gustavo; Ganame, Javier; Juaneda, Ernesto; Peirone, Alejandro; Barcudi, Maria Silvina; Achaval, Alberto

    2010-01-01

    We describe a 6-year-old girl with arterial hypertension secondary to fibromuscular dysplasia with stenoses of both renal arteries and transient ischemic attack due to extracranial right internal carotid artery subtotal occlusion as well as left internal carotid artery stenosis. She was treated with percutaneous angioplasty of both renal and both carotid arteries.

  9. Laser surveillance system (LASSY)

    International Nuclear Information System (INIS)

    Boeck, H.; Hammer, J.

    1988-01-01

    The development progress during the reporting period 1988 of the laser surveillance system of spent fuel pools is summarized. The present engineered system comes close to a final version for field application as all technical questions have been solved in 1988. 14 figs., 1 tab. (Author)

  10. Aurora laser optical system

    International Nuclear Information System (INIS)

    Hanlon, J.A.; McLeod, J.

    1987-01-01

    Aurora is the Los Alamos short-pulse high-power krypton fluoride laser system. It is primarily an end-to-end technology demonstration prototype for large-scale UV laser systems of interest for short-wavelength inertial confinement fusion (ICF) investigations. The system is designed to employ optical angular multiplexing and aerial amplification by electron-beam-driven KrF laser amplifiers to deliver to ICF targets a stack of pulses with a duration of 5 ns containing several kilojoules at a wavelength of 248 nm. A program of high-energy density plasma physics investigations is now planned, and a sophisticated target chamber was constructed. The authors describe the design of the optical system for Aurora and report its status. This optical system was designed and is being constructed in two phases. The first phase carries only through the amplifier train and does not include a target chamber or any demultiplexing. Installation should be complete, and some performance results should be available. The second phase provides demultiplexing and carries the laser light to target. The complete design is reported

  11. Laser surveillance system (LASSY)

    International Nuclear Information System (INIS)

    Boeck, H.

    1991-09-01

    Laser Surveillance System (LASSY) is a beam of laser light which scans a plane above the water or under-water in a spent-fuel pond. The system can detect different objects and estimates its coordinates and distance as well. LASSY can operate in stand-alone configuration or in combination with a video surveillance to trigger signal to a videorecorder. The recorded information on LASSY computer's disk comprises date, time, start and stop angle of detected alarm, the size of the disturbance indicated in number of deviated points and some other information. The information given by the laser system cannot be fully substituted by TV camera pictures since the scanning beam creates a horizontal surveillance plan. The engineered prototype laser system long-term field test has been carried out in Soluggia (Italy) and has shown its feasibility and reliability under the conditions of real spent fuel storage pond. The verification of the alarm table on the LASSY computer with the recorded video pictures of TV surveillance system confirmed that all alarm situations have been detected. 5 refs

  12. Coherent laser vision system

    International Nuclear Information System (INIS)

    Sebastion, R.L.

    1995-01-01

    The Coherent Laser Vision System (CLVS) is being developed to provide precision real-time 3D world views to support site characterization and robotic operations and during facilities Decontamination and Decommissioning. Autonomous or semiautonomous robotic operations requires an accurate, up-to-date 3D world view. Existing technologies for real-time 3D imaging, such as AM laser radar, have limited accuracy at significant ranges and have variability in range estimates caused by lighting or surface shading. Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no-moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic to coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system

  13. Coherent laser vision system

    Energy Technology Data Exchange (ETDEWEB)

    Sebastion, R.L. [Coleman Research Corp., Springfield, VA (United States)

    1995-10-01

    The Coherent Laser Vision System (CLVS) is being developed to provide precision real-time 3D world views to support site characterization and robotic operations and during facilities Decontamination and Decommissioning. Autonomous or semiautonomous robotic operations requires an accurate, up-to-date 3D world view. Existing technologies for real-time 3D imaging, such as AM laser radar, have limited accuracy at significant ranges and have variability in range estimates caused by lighting or surface shading. Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no-moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic to coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system.

  14. Traveling wave laser system

    International Nuclear Information System (INIS)

    Gregg, D.W.; Kidder, R.E.; Biehl, A.T.

    1975-01-01

    The invention broadly involves a method and means for generating a traveling wave laser pulse and is basically analogous to a single pass light amplifier system. However, the invention provides a traveling wave laser pulse of almost unlimited energy content, wherein a gain medium is pumped in a traveling wave mode, the traveling wave moving at essentially the velocity of light to generate an amplifying region or zone which moves through the medium at the velocity of light in the presence of directed stimulating radiation, thereby generating a traveling coherent, directed radiation pulse moving with the amplification zone through the gain medium. (U.S.)

  15. PEP Laser Surveying System

    International Nuclear Information System (INIS)

    Lauritzen, T.; Sah, R.C.

    1979-03-01

    A Laser Surveying System has been developed to survey the beam elements of the PEP storage ring. This system provides automatic data acquisition and analysis in order to increase survey speed and to minimize operator error. Two special instruments, the Automatic Readout Micrometer and the Small Automatic Micrometer, have been built for measuring the locations of fiducial points on beam elements with respect to the light beam from a laser. These instruments automatically encode offset distances and read them into the memory of an on-line computer. Distances along the beam line are automatically encoded with a third instrument, the Automatic Readout Tape Unit. When measurements of several beam elements have been taken, the on-line computer analyzes the measured data, compared them with desired parameters, and calculates the required adjustments to beam element support stands

  16. Optically pumped laser systems

    International Nuclear Information System (INIS)

    DeMaria, A.J.; Mack, M.E.

    1975-01-01

    Laser systems which are pumped by an electric discharge formed in a gas are disclosed. The discharge is in the form of a vortex stabilized electric arc which is triggered with an auxiliary energy source. At high enough repetition rates residual ionization between successive pulses contributes to the pulse stabilization. The arc and the gain medium are positioned inside an optical pumping cavity where light from the arc is coupled directly into the gain medium

  17. Angioplasty and stent placement - carotid artery

    Science.gov (United States)

    ... medlineplus.gov/ency/article/002953.htm Angioplasty and stent placement - carotid artery To use the sharing features ... to remove plaque buildup ( endarterectomy ) Carotid angioplasty with stent placement Description Carotid angioplasty and stenting (CAS) is ...

  18. Aorto-iliac angioplasty

    International Nuclear Information System (INIS)

    Kotb, M.; Bennett, J.; Kadir, S.

    1990-01-01

    This paper reports on the results and complications of aortoiliac balloon percutaneous transluminal angioplasty (PTA) and Simpson atherectomy that are compared to determine the role of the latter procedure in the management of aortoiliac disease. In 1984--1988, 92 patients underwent 126 angioplasties of the aortoiliac region. In 1986--1989, 21 patients underwent iliac artery atherectomy. Both groups had similar symptoms, risk factors, and age ranges. The overall technical success rate was 97.6or PTA and 100% for atherectomy. The initial clinical success was 92.8% for PTA and 100% for atherectomy. The 2-year clinical patency rate was 60% for PTA and 64% for artherectomy. Complications requiring surgery occurred in four of 126 (3%) PTA patients and one of 21 (5%) atherectomy patients. Groin hematomas were observed in 16% of PTA patients and 19% of atherectomy patients

  19. Application of Various Lasers to Laser Trimming Resistance System

    Institute of Scientific and Technical Information of China (English)

    SUN Ji-feng

    2007-01-01

    Though the laser trimming resistance has been an old laser machining industry for over 30 years, the development of technology brings new alternative lasers which can be used for the traditional machining. The paper describes application of various lasers to laser trimming resistance system including early traditional krypton arc lamp pumped Nd:YAG to laser, modern popular diode pumped solid state laser and the present advanced harmonic diode pumped solid state laser. Using the new alternative lasers in the laser trimming resistance system can dramatically improve the yields and equipment performance.

  20. Laser system using ultra-short laser pulses

    Science.gov (United States)

    Dantus, Marcos [Okemos, MI; Lozovoy, Vadim V [Okemos, MI; Comstock, Matthew [Milford, MI

    2009-10-27

    A laser system using ultrashort laser pulses is provided. In another aspect of the present invention, the system includes a laser, pulse shaper and detection device. A further aspect of the present invention employs a femtosecond laser and binary pulse shaping (BPS). Still another aspect of the present invention uses a laser beam pulse, a pulse shaper and a SHG crystal.

  1. Laser engineering of microbial systems

    Science.gov (United States)

    Yusupov, V. I.; Gorlenko, M. V.; Cheptsov, V. S.; Minaev, N. V.; Churbanova, E. S.; Zhigarkov, V. S.; Chutko, E. A.; Evlashin, S. A.; Chichkov, B. N.; Bagratashvili, V. N.

    2018-06-01

    A technology of laser engineering of microbial systems (LEMS) based on the method of laser-induced transfer of heterogeneous mixtures containing microorganisms (laser bioprinting) is described. This technology involves laser printing of soil microparticles by focusing near-infrared laser pulses on a specially prepared gel/soil mixture spread onto a gold-coated glass plate. The optimal range of laser energies from the point of view of the formation of stable jets and droplets with minimal negative impact on living systems of giant accelerations, laser pulse irradiation, and Au nanoparticles was found. Microsamples of soil were printed on glucose-peptone-yeast agar plates to estimate the LEMS process influence on structural and morphological microbial diversity. The obtained results were compared with traditionally treated soil samples. It was shown that LEMS technology allows significantly increasing the biodiversity of printed organisms and is effective for isolating rare or unculturable microorganisms.

  2. Design Issues for Therapeutic Ultrasound Angioplasty Waveguides

    OpenAIRE

    Noone, Declan; Gavin, Graham; McGuinness, Garrett

    2008-01-01

    Therapeutic ultrasound angioplasty is a new minimally invasive cardiovascular procedure for disrupting atherosclerotic lesions. Mechanical energy is transmitted in the form of ultrasound waves via long, flexible wire waveguides navigated to the lesion site through the vascular system. The underpinning principle of this technology is that plaque may be disrupted through a combination of direct contact ablation, pressure waves, cavitation and acoustic streaming, which all depend on the amplitud...

  3. Regenerative laser system

    International Nuclear Information System (INIS)

    Biancardi, F.R.; Landerman, A.; Melikian, G.

    1975-01-01

    Regenerative apparatus for exhausting the working medium from the optical cavity of a laser and for supplying preheated diluent to the reaction chamber of a laser is disclosed. In an aftercooler thermal energy is exchanged between the working medium exhausted from the optical cavity and a cryogenic coolant which is subsequently utilized as the motive fluid for an ejector and as a diluent in the production of laser gas. Highly toxic and corrosive gases are condensed out of the working medium as the cryogenic coolant is evaporated and superheated. A preheater transfers additional heat to the diluent before the diluent enters the reaction chamber. (U.S.)

  4. Percutaneous transluminal coronary angioplasty

    International Nuclear Information System (INIS)

    Przybojewski, J.Z.; Weich, H.F.H.

    1984-01-01

    The purpose of this article is to review PTCA, percutaneous transluminal coronary angioplasty, which can be considered to be a truly revolutionary and fairly simple invasive form of intervention to atherosclerotic obstruction. The 'epidemic' of IHD, ischaemic heart disease, in the Republic of South Africa calls for the employment of this technique, which has already been carried out in a few teaching hospitals in this country. Very recently, modified balloon dilatation catheters have been used percutaneously in the non-operative transluminal correction of congenital coarctation of the aorta in infants and children, congenital pulmonary value stenosis, and hypoplasia and stenosis of the pulmonary arteries. It has also been employed for PTCA and for the simultaneous occlusion of coronary-bronchial artery anastomosis using a detachable balloon. The isotopes thallium 201 and technetium 99 were also used in scintiscanning

  5. The GEO 600 laser system

    CERN Document Server

    Zawischa, I; Danzmann, K; Fallnich, C; Heurs, M; Nagano, S; Quetschke, V; Welling, H; Willke, B

    2002-01-01

    Interferometric gravitational wave detectors require high optical power, single frequency lasers with very good beam quality and high amplitude and frequency stability as well as high long-term reliability as input light source. For GEO 600 a laser system with these properties is realized by a stable planar, longitudinally pumped 12 W Nd:YAG rod laser which is injection-locked to a monolithic 800 mW Nd:YAG non-planar ring oscillator. Frequency control signals from the mode cleaners are fed to the actuators of the non-planar ring oscillator which determines the frequency stability of the system. The system power stabilization acts on the slave laser pump diodes which have the largest influence on the output power. In order to gain more output power, a combined Nd:YAG-Nd:YVO sub 4 system is scaled to more than 22 W.

  6. Nova laser alignment control system

    International Nuclear Information System (INIS)

    Van Arsdall, P.J.; Holloway, F.W.; McGuigan, D.L.; Shelton, R.T.

    1984-01-01

    Alignment of the Nova laser requires control of hundreds of optical components in the ten beam paths. Extensive application of computer technology makes daily alignment practical. The control system is designed in a manner which provides both centralized and local manual operator controls integrated with automatic closed loop alignment. Menudriven operator consoles using high resolution color graphics displays overlaid with transport touch panels allow laser personnel to interact efficiently with the computer system. Automatic alignment is accomplished by using image analysis techniques to determine beam references points from video images acquired along the laser chain. A major goal of the design is to contribute substantially to rapid experimental turnaround and consistent alignment results. This paper describes the computer-based control structure and the software methods developed for aligning this large laser system

  7. Laser Pyro System Standardization and Man Rating

    Science.gov (United States)

    Brown, Christopher W.

    2004-01-01

    This viewgraph presentation reviews an X-38 laser pyro system standardization system designed for a new manned rated program. The plans to approve this laser initiation system and preliminary ideas for this system are also provided.

  8. Angioplasty: MedlinePlus Health Topic

    Science.gov (United States)

    ... segment (Medical Encyclopedia) Also in Spanish Directional coronary atherectomy (DCA) (Medical Encyclopedia) Also in Spanish Percutaneous transluminal ... segment Coronary artery balloon angioplasty - slideshow Directional coronary atherectomy ... transluminal coronary angioplasty (PTCA) Stent Related ...

  9. Traveling wave laser system

    International Nuclear Information System (INIS)

    Gregg, D.W.; Kidder, R.E.; Biehl, A.T.

    1975-01-01

    A method is described for generating a traveling wave laser pulse of almost unlimited energy content wherein a gain medium is pumped into a traveling wave mode, the traveling wave moving at essentially the velocity of light to generate an amplifying region or zone which moves through the medium at the velocity of light in the presence of directed stimulating radiation, thereby generating a traveling coherent, directed radiation pulse moving with the amplification zone through the gain medium. (U.S.)

  10. Underwater laser imaging system (UWLIS)

    Energy Technology Data Exchange (ETDEWEB)

    DeLong, M. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    Practical limitations with underwater imaging systems area reached when the noise in the back scattered radiation generated in the water between the imaging system and the target obscures the spatial contrast and resolution necessary for target discovery and identification. The advent of high power lasers operating in the blue-green portion of the visible spectrum (oceanic transmission window) has led to improved experimental illumination systems for underwater imaging. Range-gated and synchronously scanned devices take advantage of the unique temporal and spatial coherence properties of laser radiation, respectively, to overcome the deleterious effects of common volume back scatter.

  11. Coronary angioplasty with second generation Monorail catheters.

    Science.gov (United States)

    Pande, A K; Meier, B; Urban, P; Villavicencio, R; de la Serna, F; Moles, V

    1991-07-01

    The Monorail system (Schneider) consists of a balloon catheter in which the guidewire passes through the balloon itself, exits the catheter proximal to the balloon, and runs alongside its small shaft (3 French) through the length of the guiding catheter. It offers distinct advantages over conventional systems of coronary angioplasty. It facilitates contrast injections and permits rapid balloon exchanges. This system was used for coronary angioplasty in 273 unselected consecutive patients (age 59 +/- 10, mean 35 to 73 years). There were 216 patients (84%) undergoing single-vessel and 57 patients (16%) with multi-vessel coronary angioplasty. A total of 335 coronary stenoses were dilated, which included 35 total occlusions. The size of balloon used ranged from 2.0 to 4.25 mm (3.0 +/- 0.5 mm) and the severity of stenosis was 85 +/- 11%. Technical success was defined as a residual stenosis of less than 50% as determined angiographically. Clinical success was defined as technical success, and absence of a major inhospital complication defined as absence of myocardial infarction, lack of need for coronary arterial bypass surgery, and survival. The Monorail system was technically successful in 294/300 stenotic lesions (98%). It was clinically successful for 281 lesions (94%). Of the 35 total occlusions, technical success was obtained in 25 (71%). The residual stenosis of successful cases was 26 +/- 21%. The Monorail system was also successful in 5 patients with stenosis of more than 90% in whom conventional systems failed. The complications included acute occlusion causing acute myocardial infarction in 13 cases (5%), emergency coronary arterial bypass surgery in 1 patient (0.4%), and death in 4 patients (1.5%).(ABSTRACT TRUNCATED AT 250 WORDS)

  12. ARGOS laser system mechanical design

    Science.gov (United States)

    Deysenroth, M.; Honsberg, M.; Gemperlein, H.; Ziegleder, J.; Raab, W.; Rabien, S.; Barl, L.; Gässler, W.; Borelli, J. L.

    2014-07-01

    ARGOS, a multi-star adaptive optics system is designed for the wide-field imager and multi-object spectrograph LUCI on the LBT (Large Binocular Telescope). Based on Rayleigh scattering the laser constellation images 3 artificial stars (at 532 nm) per each of the 2 eyes of the LBT, focused at a height of 12 km (Ground Layer Adaptive Optics). The stars are nominally positioned on a circle 2' in radius, but each star can be moved by up to 0.5' in any direction. For all of these needs are following main subsystems necessary: 1. A laser system with its 3 Lasers (Nd:YAG ~18W each) for delivering strong collimated light as for LGS indispensable. 2. The Launch system to project 3 beams per main mirror as a 40 cm telescope to the sky. 3. The Wave Front Sensor with a dichroic mirror. 4. The dichroic mirror unit to grab and interpret the data. 5. A Calibration Unit to adjust the system independently also during day time. 6. Racks + platforms for the WFS units. 7. Platforms and ladders for a secure access. This paper should mainly demonstrate how the ARGOS Laser System is configured and designed to support all other systems.

  13. Development of automatic laser welding system

    International Nuclear Information System (INIS)

    Ohwaki, Katsura

    2002-01-01

    Laser are a new production tool for high speed and low distortion welding and applications to automatic welding lines are increasing. IHI has long experience of laser processing for the preservation of nuclear power plants, welding of airplane engines and so on. Moreover, YAG laser oscillators and various kinds of hardware have been developed for laser welding and automation. Combining these welding technologies and laser hardware technologies produce the automatic laser welding system. In this paper, the component technologies are described, including combined optics intended to improve welding stability, laser oscillators, monitoring system, seam tracking system and so on. (author)

  14. Blood pressure normalization post-jugular venous balloon angioplasty.

    Science.gov (United States)

    Sternberg, Zohara; Grewal, Prabhjot; Cen, Steven; DeBarge-Igoe, Frances; Yu, Jinhee; Arata, Michael

    2015-05-01

    This study is the first in a series investigating the relationship between autonomic nervous system dysfunction and chronic cerebrospinal venous insufficiency in multiple sclerosis patients. We screened patients for the combined presence of the narrowing of the internal jugular veins and symptoms of autonomic nervous system dysfunction (fatigue, cognitive dysfunction, sleeping disorders, headache, thermal intolerance, bowel/bladder dysfunction) and determined systolic and diastolic blood pressure responses to balloon angioplasty. The criteria for eligibility for balloon angioplasty intervention included ≥ 50% narrowing in one or both internal jugular veins, as determined by the magnetic resonance venography, and ≥ 3 clinical symptoms of autonomic nervous system dysfunction. Blood pressure was measured at baseline and post-balloon angioplasty. Among patients who were screened, 91% were identified as having internal jugular veins narrowing (with obstructing lesions) combined with the presence of three or more symptoms of autonomic nervous system dysfunction. Balloon angioplasty reduced the average systolic and diastolic blood pressure. However, blood pressure categorization showed a biphasic response to balloon angioplasty. The procedure increased blood pressure in multiple sclerosis patients who presented with baseline blood pressure within lower limits of normal ranges (systolic ≤ 105 mmHg, diastolic ≤ 70 mmHg) but decreased blood pressure in patients with baseline blood pressure above normal ranges (systolic ≥ 130 mmHg, diastolic ≥ 80 mmHg). In addition, gender differences in baseline blood pressure subcategories were observed. The coexistence of internal jugular veins narrowing and symptoms of autonomic nervous system dysfunction suggests that the two phenomena may be related. Balloon angioplasty corrects blood pressure deviation in multiple sclerosis patients undergoing internal jugular vein dilation. Further studies should investigate the

  15. Some characteristics of isotopic separation laser systems

    International Nuclear Information System (INIS)

    Pochon, E.

    1988-01-01

    The principle of Laser Isotope Separation (LIS) is simple and based on either selective electronic photoexcitation and photoionization of atomic vapor, or selective vibrational photoexcitation and photodissociation of molecules in the gas phase. These processes, respectively called SILVA (AVLIS) and SILMO (MLIS) in France, both use specific laser systems with wavelengths spanning from infrared to ultraviolet. This article describes briefly some of the characteristics of a SILVA laser system. Following a three-step process, a SILVA laser system is based on dye copper vapor lasers. The pulse dye lasers provide the tunable laser light and are optically pumped by copper vapor laser operating at high repetition rates. In order to meet plant laser system requirements, the main improvements under way relate to copper vapor laser devices the power capability, efficiency, reliability and lifetime of which have to be increased. 1 fig

  16. Laser-based agriculture system

    KAUST Repository

    Ooi, Boon S.

    2016-03-31

    A system and method are provided for indoor agriculture using at least one growth chamber illuminated by laser light. In an example embodiment of the agriculture system, a growth chamber is provided having one or more walls defining an interior portion of the growth chamber. The agriculture system may include a removable tray disposed within the interior portion of the growth chamber. The agriculture system also includes a light source, which may be disposed outside the growth chamber. The one or more walls may include at least one aperture. The light source is configured to illuminate at least a part of the interior portion of the growth chamber. In embodiments in which the light source is disposed outside the growth chamber, the light source is configured to transmit the laser light to the interior portion of the growth chamber via the at least one aperture.

  17. Laser-based agriculture system

    KAUST Repository

    Ooi, Boon S.; Wong, Aloysius Tze; Ng, Tien Khee

    2016-01-01

    A system and method are provided for indoor agriculture using at least one growth chamber illuminated by laser light. In an example embodiment of the agriculture system, a growth chamber is provided having one or more walls defining an interior portion of the growth chamber. The agriculture system may include a removable tray disposed within the interior portion of the growth chamber. The agriculture system also includes a light source, which may be disposed outside the growth chamber. The one or more walls may include at least one aperture. The light source is configured to illuminate at least a part of the interior portion of the growth chamber. In embodiments in which the light source is disposed outside the growth chamber, the light source is configured to transmit the laser light to the interior portion of the growth chamber via the at least one aperture.

  18. Laser systems for on-line laser ion sources

    International Nuclear Information System (INIS)

    Geppert, Christopher

    2008-01-01

    Since its initiation in the middle of the 1980s, the resonant ionization laser ion source has been established as a reliable and efficient on-line ion source for radioactive ion beams. In comparison to other on-line ion sources it comprises the advantages of high versatility for the elements to be ionized and of high selectivity and purity for the ion beam generated by resonant laser radiation. Dye laser systems have been the predominant and pioneering working horses for laser ion source applications up to recently, but the development of all-solid-state titanium:sapphire laser systems has nowadays initiated a significant evolution within this field. In this paper an overview of the ongoing developments will be given, which have contributed to the establishment of a number of new laser ion source facilities worldwide during the last five years.

  19. High speed laser tomography system

    Science.gov (United States)

    Samsonov, D.; Elsaesser, A.; Edwards, A.; Thomas, H. M.; Morfill, G. E.

    2008-03-01

    A high speed laser tomography system was developed capable of acquiring three-dimensional (3D) images of optically thin clouds of moving micron-sized particles. It operates by parallel-shifting an illuminating laser sheet with a pair of galvanometer-driven mirrors and synchronously recording two-dimensional (2D) images of thin slices of the imaged volume. The maximum scanning speed achieved was 120000slices/s, sequences of 24 volume scans (up to 256 slices each) have been obtained. The 2D slices were stacked to form 3D images of the volume, then the positions of the particles were identified and followed in the consecutive scans. The system was used to image a complex plasma with particles moving at speeds up to cm/s.

  20. Distal coronary hemoperfusion during percutaneous transluminal coronary angioplasty

    NARCIS (Netherlands)

    Muinck, Ebo Derk de

    1994-01-01

    In this thesis several aspects of passive and active coronary perfusion during coronary angioplasty are investigated. The autoperfusion balloon catheters that were evaluated are the Stack® and the RX-60® catheters (Advanced Cardiovascular Systems, inc., Santa Clara, California, U.S.A). The coronary

  1. Navigated Pattern Laser System versus Single-Spot Laser System for Postoperative 360-Degree Laser Retinopexy.

    Science.gov (United States)

    Kulikov, Alexei N; Maltsev, Dmitrii S; Boiko, Ernest V

    2016-01-01

    Purpose . To compare three 360°-laser retinopexy (LRP) approaches (using navigated pattern laser system, single-spot slit-lamp (SL) laser delivery, and single-spot indirect ophthalmoscope (IO) laser delivery) in regard to procedure duration, procedural pain score, technical difficulties, and the ability to achieve surgical goals. Material and Methods . Eighty-six rhegmatogenous retinal detachment patients (86 eyes) were included in this prospective randomized study. The mean procedural time, procedural pain score (using 4-point Verbal Rating Scale), number of laser burns, and achievement of the surgical goals were compared between three groups (pattern LRP (Navilas® laser system), 36 patients; SL-LRP, 28 patients; and IO-LRP, 22 patients). Results . In the pattern LRP group, the amount of time needed for LRP and pain level were statistically significantly lower, whereas the number of applied laser burns was higher compared to those in the SL-LRP group and in the IO-LRP group. In the pattern LRP, SL-LRP, and IO-LRP groups, surgical goals were fully achieved in 28 (77.8%), 17 (60.7%), and 13 patients (59.1%), respectively ( p > 0.05). Conclusion . The navigated pattern approach allows improving the treatment time and pain in postoperative 360° LRP. Moreover, 360° pattern LRP is at least as effective in achieving the surgical goal as the conventional (slit-lamp or indirect ophthalmoscope) approaches with a single-spot laser.

  2. Improvements of the ruby laser oscillator system for laser scattering

    International Nuclear Information System (INIS)

    Yamauchi, Toshihiko; Kumagai, Katsuaki; Kawakami, Tomohide; Matoba, Tohru; Funahashi, Akimasa

    1978-10-01

    A ruby laser oscillator system is used to measure electron temperatures of the Tokamak plasmas(JFT-2 and JFT-2a). Improvements have been made of the laser oscillator to obtain the correct values. Described are the improvements and the damages of a ruby rod and a KD*P crystal for Q-switching by laser beam. Improvement are the linear Xe lamp replaced by a helical Xe lamp and in the electrical circuit for Q-switching. The damage of an optical component by a laser beam should be clarified from the damage data; the cause is not found yet. (author)

  3. Laser spark distribution and ignition system

    Science.gov (United States)

    Woodruff, Steven [Morgantown, WV; McIntyre, Dustin L [Morgantown, WV

    2008-09-02

    A laser spark distribution and ignition system that reduces the high power optical requirements for use in a laser ignition and distribution system allowing for the use of optical fibers for delivering the low peak energy pumping pulses to a laser amplifier or laser oscillator. An optical distributor distributes and delivers optical pumping energy from an optical pumping source to multiple combustion chambers incorporating laser oscillators or laser amplifiers for inducing a laser spark within a combustion chamber. The optical distributor preferably includes a single rotating mirror or lens which deflects the optical pumping energy from the axis of rotation and into a plurality of distinct optical fibers each connected to a respective laser media or amplifier coupled to an associated combustion chamber. The laser spark generators preferably produce a high peak power laser spark, from a single low power pulse. The laser spark distribution and ignition system has application in natural gas fueled reciprocating engines, turbine combustors, explosives and laser induced breakdown spectroscopy diagnostic sensors.

  4. Fission fragment excited laser system

    Science.gov (United States)

    McArthur, David A.; Tollefsrud, Philip B.

    1976-01-01

    A laser system and method for exciting lasing action in a molecular gas lasing medium which includes cooling the lasing medium to a temperature below about 150 K and injecting fission fragments through the lasing medium so as to preferentially excite low lying vibrational levels of the medium and to cause population inversions therein. The cooled gas lasing medium should have a mass areal density of about 5 .times. 10.sup.-.sup.3 grams/square centimeter, relaxation times of greater than 50 microseconds, and a broad range of excitable vibrational levels which are excitable by molecular collisions.

  5. 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...

  6. Laser and photonic systems design and integration

    CERN Document Server

    Nof, Shimon Y; Cheng, Gary J

    2014-01-01

    New, significant scientific discoveries in laser and photonic technologies, systems perspectives, and integrated design approaches can improve even further the impact in critical areas of challenge. Yet this knowledge is dispersed across several disciplines and research arenas. Laser and Photonic Systems: Design and Integration brings together a multidisciplinary group of experts to increase understanding of the ways in which systems perspectives may influence laser and photonic innovations and application integration.By bringing together chapters from leading scientists and technologists, ind

  7. Multiplex electric discharge gas laser system

    Science.gov (United States)

    Laudenslager, James B. (Inventor); Pacala, Thomas J. (Inventor)

    1987-01-01

    A multiple pulse electric discharge gas laser system is described in which a plurality of pulsed electric discharge gas lasers are supported in a common housing. Each laser is supplied with excitation pulses from a separate power supply. A controller, which may be a microprocessor, is connected to each power supply for controlling the application of excitation pulses to each laser so that the lasers can be fired simultaneously or in any desired sequence. The output light beams from the individual lasers may be combined or utilized independently, depending on the desired application. The individual lasers may include multiple pairs of discharge electrodes with a separate power supply connected across each electrode pair so that multiple light output beams can be generated from a single laser tube and combined or utilized separately.

  8. Materials for spaceborne laser systems

    International Nuclear Information System (INIS)

    Gusarov, A.

    2006-01-01

    Advanced laser systems are attracting a growing interest for space missions, in particular for LIDAR (LIght Detection And Ranging) applications. An important issue for the LIDARs is the very strict requirements on the optical performance and more specifically the need for a high optical output power combined with a nearly perfect output beam quality. These features are traditionally in conflict with each other. Thermally induced phase distortions indeed corrupt the beam quality of high-power solid-state lasers and it becomes increasingly difficult to maintain a good beam quality while increasing the output power. A possible solution of the problem is to use the optical phase conjugation, which provides a method to dynamically correct for those aberrations. A process by which phase-conjugated waves can be generated is the SBS (stimulated Brillouin scattering). SBS mirrors commonly used in terrestrial application are based on liquids or gases, which are not 'space-friendly' and often toxic. The solid-state alternative seems the most appropriate for space. Such PCMs (Phase-Conjugating Mirrors) have been the subject of many research efforts in recent years and a significant progress in improving their characteristics has been achieved. However, the issue of space qualification remains open. To address it, the European Space Agency initiated in 2004 the research project named Solid-State Phase Conjugation, Radiation Testing and Evaluation for Core Laser Technologies with the TRT (Thales Research and Technology), France, as the prime contractor, and the CSL (Centre Spatial de Liege) and SCKCEN as the subcontractors. The project is to be completed in 2006. To qualify a PCM for a spaceborne laser system, one has to address a number of specific issues. Such a component must be mechanically rugged to sustain vibrations during the launch phase, provide a low out-gassing to prevent optical surfaces contamination in vacuum, be highly reliable to operate properly without

  9. Dynamically variable spot size laser system

    Science.gov (United States)

    Gradl, Paul R. (Inventor); Hurst, John F. (Inventor); Middleton, James R. (Inventor)

    2012-01-01

    A Dynamically Variable Spot Size (DVSS) laser system for bonding metal components includes an elongated housing containing a light entry aperture coupled to a laser beam transmission cable and a light exit aperture. A plurality of lenses contained within the housing focus a laser beam from the light entry aperture through the light exit aperture. The lenses may be dynamically adjusted to vary the spot size of the laser. A plurality of interoperable safety devices, including a manually depressible interlock switch, an internal proximity sensor, a remotely operated potentiometer, a remotely activated toggle and a power supply interlock, prevent activation of the laser and DVSS laser system if each safety device does not provide a closed circuit. The remotely operated potentiometer also provides continuous variability in laser energy output.

  10. National Ignition Facility system design requirements Laser System SDR002

    International Nuclear Information System (INIS)

    Larson, D.W.; Bowers, J.M.; Bliss, E.S.; Karpenko, V.P.; English, E.

    1996-01-01

    This System Design Requirement document establishes the performance, design, development, and test requirements for the NIP Laser System. The Laser System generates and delivers high-power optical pulses to the target chamber, and is composed of all optical puke creating and transport elements from Puke Generation through Final Optics as well as the special equipment that supports, energizes and controls them. The Laser System consists of the following WBS elements: 1.3 Laser System 1.4 Beam Transport System 1.6 Optical Components 1.7 Laser Control 1.8.7 Final Optics

  11. High-performance OPCPA laser system

    International Nuclear Information System (INIS)

    Zuegel, J.D.; Bagnoud, V.; Bromage, J.; Begishev, I.A.; Puth, J.

    2006-01-01

    Optical parametric chirped-pulse amplification (OPCPA) is ideally suited for amplifying ultra-fast laser pulses since it provides broadband gain across a wide range of wavelengths without many of the disadvantages of regenerative amplification. A high-performance OPCPA system has been demonstrated as a prototype for the front end of the OMEGA Extended Performance (EP) Laser System. (authors)

  12. High-performance OPCPA laser system

    Energy Technology Data Exchange (ETDEWEB)

    Zuegel, J.D.; Bagnoud, V.; Bromage, J.; Begishev, I.A.; Puth, J. [Rochester Univ., Lab. for Laser Energetics, NY (United States)

    2006-06-15

    Optical parametric chirped-pulse amplification (OPCPA) is ideally suited for amplifying ultra-fast laser pulses since it provides broadband gain across a wide range of wavelengths without many of the disadvantages of regenerative amplification. A high-performance OPCPA system has been demonstrated as a prototype for the front end of the OMEGA Extended Performance (EP) Laser System. (authors)

  13. Laser surveillance system for spent fuel

    International Nuclear Information System (INIS)

    Fiarman, S.; Zucker, M.S.; Bieber, A.M. Jr.

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools (SFSP's) will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a full size laser system operating in air and have used an array of 6 zircaloy BWR tubes to simulate an assembly. The reflective signal from the zircaloy rods is a strong function of position of the assembly, but in all cases is easily discernable from the reference scan of the background with no assembly. A design for a SFSP laser surveillance system incorporating laser ranging is discussed. 10 figures

  14. The Theory of Random Laser Systems

    International Nuclear Information System (INIS)

    Xunya Jiang

    2002-01-01

    Studies of random laser systems are a new direction with promising potential applications and theoretical interest. The research is based on the theories of localization and laser physics. So far, the research shows that there are random lasing modes inside the systems which is quite different from the common laser systems. From the properties of the random lasing modes, they can understand the phenomena observed in the experiments, such as multi-peak and anisotropic spectrum, lasing mode number saturation, mode competition and dynamic processes, etc. To summarize, this dissertation has contributed the following in the study of random laser systems: (1) by comparing the Lamb theory with the Letokhov theory, the general formulas of the threshold length or gain of random laser systems were obtained; (2) they pointed out the vital weakness of previous time-independent methods in random laser research; (3) a new model which includes the FDTD method and the semi-classical laser theory. The solutions of this model provided an explanation of the experimental results of multi-peak and anisotropic emission spectra, predicted the saturation of lasing modes number and the length of localized lasing modes; (4) theoretical (Lamb theory) and numerical (FDTD and transfer-matrix calculation) studies of the origin of localized lasing modes in the random laser systems; and (5) proposal of using random lasing modes as a new path to study wave localization in random systems and prediction of the lasing threshold discontinuity at mobility edge

  15. The feasibility of transradial laser atherectomy for chronic total occlusion using the 5 Fr sheath system

    Directory of Open Access Journals (Sweden)

    Khaled Sherif

    2016-05-01

    Full Text Available Objective. We present a case of chronic total occlusion (CTO approached with LASER endovascular intervention by radial artery approach using a 5 French sheath. Case report. A 57-year-old man presented to our hospital having had retrosternal chest pain for two days. Physical examination was normal at the time of presentation. The laboratory tests were within normal limits, including cardiac enzymes except the lipid panel which showed hypertriglyceridemia. The patient underwent a myocardial perfusion scintigraphy stress test that revealed inferior wall ischemia, with normal left ventricular ejection fraction. A 5-French vascular sheath was placed in the right radial artery. Selective coronary artery angiography was performed, which showed right coronary artery (RCA CTO. A 5-French JR4 guide catheter successfully engaged the RCA and Laser angioplasty was performed across the CTO into the RCA. A marked improvement of flow was evident thereafter. Conclusion. To best of our knowledge this is the first case report showing the feasibility of laser atherectomy using the 5 French sheath system in a coronary arterial CTO.

  16. The feasibility of transradial laser atherectomy for chronic total occlusion using the 5 Fr sheath system.

    Science.gov (United States)

    Sherif, Khaled; Yaqub, Yasir; Suarez, Jose A

    2016-05-01

    We present a case of chronic total occlusion (CTO) approached with LASER endovascular intervention by radial artery approach using a 5 French sheath. A 57-year-old man presented to our hospital having had retrosternal chest pain for two days. Physical examination was normal at the time of presentation. The laboratory tests were within normal limits, including cardiac enzymes except the lipid panel which showed hypertriglyceridemia. The patient underwent a myocardial perfusion scintigraphy stress test that revealed inferior wall ischemia, with normal left ventricular ejection fraction. A 5-French vascular sheath was placed in the right radial artery. Selective coronary artery angiography was performed, which showed right coronary artery (RCA) CTO. A 5-French JR4 guide catheter successfully engaged the RCA and Laser angioplasty was performed across the CTO into the RCA. A marked improvement of flow was evident thereafter. To best of our knowledge this is the first case report showing the feasibility of laser atherectomy using the 5 French sheath system in a coronary arterial CTO. Copyright © 2016 by Academy of Sciences and Arts of Bosnia and Herzegovina.

  17. Multi-terawatt fusion laser systems

    International Nuclear Information System (INIS)

    Holzrichter, J.F.

    1993-01-01

    The evolution of laser fusion systems started with a description of the basic principles of the laser in 1959, then a physical demonstration showing 1000 Watts of peak optical power in 1961 to the present systems that deliver 10 14 watts of peak optical power, are presented. Physical limits to large systems are reviewed: thermal limits, material stress limits, structural limits and stability, parasitic coupling, measurement precision and diagnostics. The various steps of the fusion laser-system development process are then discussed through an historical presentation. 3 figs., 8 refs

  18. Cerebral angioplasty practice at major medical centers in the United States

    International Nuclear Information System (INIS)

    Chaturvedi, S.; St Pierre, M.E.; Bertasio, B.

    2000-01-01

    Concern has been expressed recently regarding the proliferation of angioplasty and/or stenting of cerebral vessels. However, little is known about the volume of angioplasties being performed or the number of experienced interventionalists. A questionnaire was mailed to directors of accredited radiology residency programs in the United States, to define the level of expertise available at teaching hospitals in terms of angioplasty and/or stenting. Of 200 programs surveyed, 111 responded (56 %). Of 111 program directors 47 (42 %) indicated that cerebral angioplasty was being performed at their center. The greatest experience is currently for angioplasty of post-subarachnoid hemorrhage vasospasm (mean 16 procedures performed) and the least experience for dilation of basilar artery atherosclerosis (mean five procedures performed). The reported stroke and/or death rate in centers performing angioplasty of the extracranial carotid system is 1.5 %. Comparisons with other medical specialties (e. g., cardiologists, neurologists, neurosurgeons) are necessary to determine the full scope of extracranial neurovascular procedures being performed and the corresponding complication rates. (orig.)

  19. Infrared laser scattering system for plasma diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Muraoka, K; Hiraki, N; Kawasaki, S [Kyushu Univ., Fukuoka (Japan). Research Inst. for Applied Mechanics

    1975-05-01

    The possibility of observing the collective scattering of infrared laser light from plasmas is discussed in terms of the laser power requirement, the necessary optical system and the detector performance, and is shown to be feasible with the present day techniques to get the ion temperature by means of a CO/sub 2/ laser on theta pinch plasmas. Based on this estimate, the construction of the TEA CO/sub 2/ laser and the preparations of the optical components have been started and some preliminary results of these are described.

  20. Infrared laser scattering system for plasma diagnostics

    International Nuclear Information System (INIS)

    Muraoka, Katsunori; Hiraki, Naoji; Kawasaki, Shoji

    1975-01-01

    The possibility of observing the collective scattering of infrared laser light from plasmas is discussed in terms of the laser power requirement, the necessary optical system and the detector performance, and is shown to be feasible with the present day techniques to get the ion temperature by means of a CO 2 laser on theta pinch plasmas. Based on this estimate, the construction of the TEA CO 2 laser and the preparations of the optical components have been started and some preliminary results of these are described. (auth.)

  1. Multitube coaxial closed cycle gas laser system

    International Nuclear Information System (INIS)

    Davis, J.W.; Walch, A.P.

    1975-01-01

    A gas laser design capable of long term reliable operation in a commercial environment is disclosed. Various construction details which insulate the laser optics from mechanical distortions and vibrations inevitably present in the environment are developed. Also, a versatile optical cavity made up of modular units which render the basic laser configuration adaptable to alternate designs with different output capabilities is shown in detail. The system built around a convection laser operated in a closed cycle and the working medium is a gas which is excited by direct current electric discharges. (auth)

  2. Laser systems with diamond optical elements

    International Nuclear Information System (INIS)

    Seitz, J.R.

    1975-01-01

    High power laser systems with optical elements of diamond having a thermal conductivity of at least 10 W/cm. 0 K at 300 0 K and an optical absorption at the laser beam wavelength of no more than 10 to 20 percent are described. (U.S.)

  3. Blue laser phase change recording system

    International Nuclear Information System (INIS)

    Hofmann, Holger; Dambach, S.Soeren; Richter, Hartmut

    2002-01-01

    The migration paths from DVD phase change recording with red laser to the next generation optical disk formats with blue laser and high NA optics are discussed with respect to optical aberration margins and disc capacities. A test system for the evaluation of phase change disks with more than 20 GB capacity is presented and first results of the recording performance are shown

  4. Percutaneous transluminal angioplasty in arteriosclerosis

    International Nuclear Information System (INIS)

    Chung, Soo Young; Cha, In Ho

    1984-01-01

    Percutaneous transluminal angioplasty (PTA) is a non-operative therapeutic procedure to the dilation of stenosis or to the recanalization of occlusion in atherosclerotic arteries using of dilatation catheters. PTA was performed 37 times in 34 patients with arteriosclerotic for 1 year and 4 months from March, 1982 to June, 1983 at department of radiology, Klinikum Barmen/west Germany. The results were as follows; 1. The male to female ratio was 2 : 1 and peak age range was from 61 to 70. 2. The most common indication was clinical stage II b with 19 cases (51.3%). 3. PTA was performed most commonly in superficial femora artery in 25 cases (67.5%). 4. Acute major complication occurred in 2 cases (5.4%). PTA is a alternative or complementary therapeutic procedure to vascular surgery.

  5. Angioplasty and stent placement - carotid artery - discharge

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000235.htm Angioplasty and stent placement - carotid artery - discharge To use the sharing ... the hospital. You may have also had a stent (a tiny wire mesh tube) placed in the ...

  6. Angioplasty and stent placement - peripheral arteries - discharge

    Science.gov (United States)

    ... medlineplus.gov/ency/patientinstructions/000234.htm Angioplasty and stent placement - peripheral arteries - discharge To use the sharing ... peripheral artery). You may have also had a stent placed. To perform the procedure: Your doctor inserted ...

  7. Angioplasty and stent placement - peripheral arteries

    Science.gov (United States)

    ... medlineplus.gov/ency/article/007393.htm Angioplasty and stent placement - peripheral arteries To use the sharing features ... inside the arteries and block blood flow. A stent is a small, metal mesh tube that keeps ...

  8. Percutaneous transluminal angioplasty of the carotid artery

    International Nuclear Information System (INIS)

    Numaguchi, Y.; Tulane Univ., New Orleans, LA; Puyau, F.A.; Provenza, L.J.; Richardson, D.E.

    1984-01-01

    The successful dilatation of postsurgical concentric stenosis of an internal carotid artery using percutaneous transluminal angioplasty (PTA) is reported here. Only one such case has been previously documented. Review of the literature disclosed 16 patients who received transluminal angioplasty for stenosis of carotid arteries by percutaneous or open arteriotomy techniques. The authors feel that PTA may be the treatment of choice for postoperative concentric stenosis of a short segment of the carotid artery as opposed to surgical repair. (orig.)

  9. Magnetically switched power supply system for lasers

    Science.gov (United States)

    Pacala, Thomas J. (Inventor)

    1987-01-01

    A laser power supply system is described in which separate pulses are utilized to avalanche ionize the gas within the laser and then produce a sustained discharge to cause the gas to emit light energy. A pulsed voltage source is used to charge a storage device such as a distributed capacitance. A transmission line or other suitable electrical conductor connects the storage device to the laser. A saturable inductor switch is coupled in the transmission line for containing the energy within the storage device until the voltage level across the storage device reaches a predetermined level, which level is less than that required to avalanche ionize the gas. An avalanche ionization pulse generating circuit is coupled to the laser for generating a high voltage pulse of sufficient amplitude to avalanche ionize the laser gas. Once the laser gas is avalanche ionized, the energy within the storage device is discharged through the saturable inductor switch into the laser to provide the sustained discharge. The avalanche ionization generating circuit may include a separate voltage source which is connected across the laser or may be in the form of a voltage multiplier circuit connected between the storage device and the laser.

  10. Target isolation system, high power laser and laser peening method and system using same

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd A.; Harris, Fritz

    2007-11-06

    A system for applying a laser beam to work pieces, includes a laser system producing a high power output beam. Target delivery optics are arranged to deliver the output beam to a target work piece. A relay telescope having a telescope focal point is placed in the beam path between the laser system and the target delivery optics. The relay telescope relays an image between an image location near the output of the laser system and an image location near the target delivery optics. A baffle is placed at the telescope focal point between the target delivery optics and the laser system to block reflections from the target in the target delivery optics from returning to the laser system and causing damage.

  11. Repetitive output laser system and method using target reflectivity

    International Nuclear Information System (INIS)

    Johnson, R.R.

    1978-01-01

    An improved laser system and method for implosion of a thermonuclear fuel pellet is described in which that portion of a laser pulse reflected by the target pellet is utilized in the laser system to initiate a succeeding target implosion, and in which the energy stored in the laser system to amplify the initial laser pulse, but not completely absorbed thereby, is used to amplify succeeding laser pulses initiated by target refγlection

  12. Laser puncture therapy of nervous system disorders

    Energy Technology Data Exchange (ETDEWEB)

    Anishchenko, G.; Kochetkov, V.

    1984-08-29

    The authors discuss experience with treatment of nervous system disorders by means of laser-puncture therapy. Commenting on the background of the selection of this type of treatment, they explain that once researchers determined the biological action of laser light on specific nerve receptors of the skin, development of laser apparatus capable of concentrating the beam in the millimeter band was undertaken. The devices that are being used for laser-puncture are said to operate in the red helium-neon band of light. The authors identify beam parameters that have been selected for different groups of acupuncture points of the skin, and the courses of treatment (in seconds of radiation) and their time intervals. They go on to discuss the results of treatment of over 800 patients categorized in a group with disorders of the peripheral nervous system and a second group with disorders of the central nervous system.

  13. ISOLDE gets a new laser system

    CERN Multimedia

    Anaïs Schaeffer

    2011-01-01

    It's action stations at ISOLDE, the On-Line Isotope Mass Separator at CERN. The Laboratory is preparing to add a second laser ion source system to its arsenal. By alternating between two laser systems, the ISOLDE team will be able to switch from one type of beam to another in record time.   Bruce Marsh, from the EN-STI Group, with one of the lasers from ISOLDE's current system. The first laser source for producing radioactive ion beams (see box) was installed in the ISOLDE hall in the 1990s. This method, which was highly innovative for its time, has since been adopted by several laboratories all over the world. "This laser system allows us to control the ionisation wavelength with precision and thus to select specific atoms in order to produce very pure radioactive ion beams," explains Valentin Fedosseev of the EN Department. "These beams are then used for various experiments, in nuclear astrophysics and biology, for example. With two laser systems we will be able to do ...

  14. Large laser system facility design

    International Nuclear Information System (INIS)

    Gilmartin, T.J.

    1983-01-01

    Optical stability of foundations and support structures, environmental control, close-in subsystem integration, spatial organization, materiel flow and access to remote subsystems is discussed and compared for four laser facilities: The Special Isotope Separation Laboratory, Argus, Shiva/Nova, and Firepond

  15. Laser systems for ablative fractional resurfacing

    DEFF Research Database (Denmark)

    Paasch, Uwe; Haedersdal, Merete

    2011-01-01

    of a variety of skin conditions, primarily chronically photodamaged skin, but also acne and burn scars. In addition, it is anticipated that AFR can be utilized in the laser-assisted delivery of topical drugs. Clinical efficacy coupled with minimal downtime has driven the development of various fractional...... ablative laser systems. Fractionated CO(2) (10,600-nm), erbium yttrium aluminum garnet, 2940-nm and yttrium scandium gallium garnet, 2790-nm lasers are available. In this article, we present an overview of AFR technology, devices and histopathology, and we summarize the current clinical possibilities...

  16. Laser systems for ablative fractional resurfacing

    DEFF Research Database (Denmark)

    Paasch, Uwe; Haedersdal, Merete

    2011-01-01

    ablative laser systems. Fractionated CO(2) (10,600-nm), erbium yttrium aluminum garnet, 2940-nm and yttrium scandium gallium garnet, 2790-nm lasers are available. In this article, we present an overview of AFR technology, devices and histopathology, and we summarize the current clinical possibilities...... of a variety of skin conditions, primarily chronically photodamaged skin, but also acne and burn scars. In addition, it is anticipated that AFR can be utilized in the laser-assisted delivery of topical drugs. Clinical efficacy coupled with minimal downtime has driven the development of various fractional...

  17. Wavefront compensation applied to AVLIS laser systems

    International Nuclear Information System (INIS)

    Gonsiorowski, T.; Wirth, A.

    1995-01-01

    The efficiency of an AVLIS system depends upon the power density and uniformity of the laser system. Because of wavefront aberrations the realized beam quality is not ideal. Wavefront compensation provides a means to improve beam quality and system efficiency. (author)

  18. Cerebral intolerance during flow arrested carotid angioplasty.

    Science.gov (United States)

    St Louis, Myron; Park, Brian D; Dahn, Michael; Bozeman, Patricia

    2012-01-01

    The use of flow arrest as a means of providing cerebral protection during carotid angioplasty offers the advantages of improved efficiency of debris removal and the ability to provide protection under unfavorable (tortuous) anatomic circumstances. However, in contrast to the filtration methods of cerebral protection, this modality requires complete interruption of antegrade carotid artery flow during balloon angioplasty and stent deployment. We report our experience with 9 patients undergoing carotid angioplasty with the Mo.Ma device, which utilizes common and external carotid artery balloon occlusion during the angioplasty procedure. We assessed the clinical outcomes and intraprocedural hemodynamic data. The average duration of carotid occlusion was 8.3 minutes. Of the 9 patients, 2 patients (22%) experienced cerebral intolerance. No stroke occurred in this patient cohort. There appeared to be a poor relationship between procedure intolerance and the presence of significant contralateral stenosis or low carotid back pressure. Furthermore, the incidence of postangioplasty hypotension was not clearly related to cerebral intolerance. Carotid angioplasty with stenting can be safely conducted with flow arrest as an alternative to filter-type cerebral protection devices. However, because cerebral intolerance is not an infrequent occurrence with this approach, clinicians must be cognizant of management strategies for transient cerebral intolerance.

  19. Robotic Laser Coating Removal System

    Science.gov (United States)

    2008-07-01

    using a transverse excitation at atmospheric pressure (TEA) method. o Excimer lasers use reactive gases, such as chlorine and fluorine , mixed with... Varnish , and Related Products on Test Panels.   All topcoats were applied over the primer within the manufacturer’s recommended time and  artificially aged

  20. Laser surveillance system for spent fuel

    International Nuclear Information System (INIS)

    Fiarman, S.; Zucker, M.S.; Bieber, A.M. Jr.

    1980-01-01

    A laser surveillance system installed at spent fuel storage pools will provide the safeguard inspector with specific knowledge of spent fuel movement that cannot be obtained with current surveillance systems. The laser system will allow for the division of the pool's spent fuel inventory into two populations - those assemblies which have been moved and those which haven't - which is essential for maximizing the efficiency and effectiveness of the inspection effort. We have designed, constructed, and tested a laser system and have used it with a simulated BWR assembly. The reflected signal from the zircaloy rods depends on the position of the assembly, but in all cases is easily discernable from the reference scan of background with no assembly

  1. Fiber laser front end for high energy petawatt laser systems

    International Nuclear Information System (INIS)

    Dawson, J W; Messerly, M J; Phan, H; Mitchell, S; Drobshoff, A; Beach, R J; Siders, C; Lucianetti, A; Crane, J K; Barty, C J

    2006-01-01

    We are developing a fiber laser front end suitable for high energy petawatt laser systems on large glass lasers such as NIF. The front end includes generation of the pulses in a fiber mode-locked oscillator, amplification and pulse cleaning, stretching of the pulses to >3ns, dispersion trimming, timing, fiber transport of the pulses to the main laser bay and amplification of the pulses to an injection energy of 150 (micro)J. We will discuss current status of our work including data from packaged components. Design detail such as how the system addresses pulse contrast, dispersion trimming and pulse width adjustment and impact of B-integral on the pulse amplification will be discussed. A schematic of the fiber laser system we are constructing is shown in figure 1 below. A 40MHz packaged mode-locked fiber oscillator produces ∼1nJ pulses which are phase locked to a 10MHz reference clock. These pulses are down selected to 100kHz and then amplified while still compressed. The amplified compressed pulses are sent through a non-linear polarization rotation based pulse cleaner to remove background amplified spontaneous emission (ASE). The pulses are then stretched by a chirped fiber Bragg grating (CFBG) and then sent through a splitter. The splitter splits the signal into two beams. (From this point we follow only one beam as the other follows an identical path.) The pulses are sent through a pulse tweaker that trims dispersion imbalances between the final large optics compressor and the CFBG. The pulse tweaker also permits the dispersion of the system to be adjusted for the purpose of controlling the final pulse width. Fine scale timing between the two beam lines can also be adjusted in the tweaker. A large mode area photonic crystal single polarization fiber is used to transport the pulses from the master oscillator room to the main laser bay. The pulses are then amplified a two stage fiber amplifier to 150mJ. These pulses are then launched into the main amplifier

  2. Angiographic assessment of initial balloon angioplasty results.

    Science.gov (United States)

    Gardiner, Geoffrey A; Sullivan, Kevin L; Halpern, Ethan J; Parker, Laurence; Beck, Margaret; Bonn, Joseph; Levin, David C

    2004-10-01

    To determine the influence of three factors involved in the angiographic assessment of balloon angioplasty-interobserver variability, operator bias, and the definition used to determine success-on the primary (technical) results of angioplasty in the peripheral arteries. Percent stenosis in 107 lesions in lower-extremity arteries was graded by three independent, experienced vascular radiologists ("observers") before and after balloon angioplasty and their estimates were compared with the initial interpretations reported by the physician performing the procedure ("operator") and an automated quantitative computer analysis. Observer variability was measured with use of intraclass correlation coefficients and SD. Differences among the operator, observers, and the computer were analyzed with use of the Wilcoxon signed-rank test and analysis of variance. For each evaluator, the results in this series of lesions were interpreted with three different definitions of success. Estimation of residual stenosis varied by an average range of 22.76% with an average SD of 8.99. The intraclass correlation coefficients averaged 0.59 for residual stenosis after angioplasty for the three observers but decreased to 0.36 when the operator was included as the fourth evaluator. There was good to very good agreement among the three independent observers and the computer, but poor correlation with the operator (P definition of success was used. Significant differences among the operator, the three observers, and the computer were not present when the definition of success was based on less than 50% residual stenosis. Observer variability and bias in the subjective evaluation of peripheral angioplasty can have a significant influence on the reported initial success rates. This effect can be largely eliminated with the use of residual stenosis of less than 50% to define success. Otherwise, meaningful evaluation of angioplasty results will require independent panels of evaluators or

  3. System for increasing laser pulse rate

    International Nuclear Information System (INIS)

    1980-01-01

    A technique of static elements is disclosed for combining a plurality of laser beams having time sequenced, pulsed radiation to achieve an augmented pulse rate. The technique may also be applied in a system for combining both time sequenced pulses and frequency distinct pulses for use in a system for isotope enrichment. (author)

  4. Correlation control theory of chaotic laser systems

    International Nuclear Information System (INIS)

    Li Fuli.

    1986-04-01

    A novel control theory of chaotic systems is studied. The correlation functions are calculated and used as feedback signals of the chaotic lasers. Computer experiments have shown that in this way the chaotic systems can be controlled to have time-independent output when the external control parameters are in chaotic domain. (author)

  5. Image digitizer system for bubble chamber laser

    International Nuclear Information System (INIS)

    Haggerty, H.

    1986-01-01

    An IBM PC-based image digitizer system has been assembled to monitor the laser flash used for holography at the 15 foot bubble chamber. The hardware and the operating software are outlined. For an operational test of the system, an array of LEDs was flashed with a 10 microsecond pulse and the image was grabbed by one of the operating programs and processed

  6. Control system for JAERI Free Electron Laser

    International Nuclear Information System (INIS)

    Sugimoto, Masayoshi

    1992-01-01

    A control system comprising of the personal computers network and the CAMAC stations for the JAERI Free Electron Laser is designed and is in the development stage. It controls the equipment and analyzes the electron and optical beam experiments. The concept and the prototype of the control system are described. (author)

  7. Stent-assisted angioplasty for intracranial atherosclerosis

    International Nuclear Information System (INIS)

    Nakahara, Toshinori; Sakamoto, Shigeyuki; Hamasaki, Osamu; Sakoda, Katsuaki

    2002-01-01

    We report on two patients with intracranial atherosclerosis of the carotid artery or vertebral artery treated with stent-assisted angioplasty. Both patients have severe intracranial atherosclerosis (>70%) with refractory symptoms despite optimal medical treatment. In both patients, a coronary balloon-expandable stent was successfully placed using a protective balloon technique without procedural complications. The patients were asymptomatic and neurologically intact at a mean clinical follow-up of 13 months. Follow-up angiograms did not show restenosis 3 or 4 months after procedure, respectively. Stent-assisted angioplasty for intracranial atherosclerosis in the elective patient has proven effective, with an acceptable low rate of morbidity and mortality. (orig.)

  8. PHASE NOISE COMPARISON OF SHORT PULSE LASER SYSTEMS

    Energy Technology Data Exchange (ETDEWEB)

    Shukui Zhang; Stephen Benson; John Hansknecht; David Hardy; George Neil; Michelle D. Shinn

    2006-08-27

    This paper describes phase noise measurements of several different laser systems that have completely different gain media and configurations including a multi-kW free-electron laser. We will focus on state-of-the-art short pulse lasers, especially drive lasers for photocathode injectors. Phase noise comparison of the FEL drive laser, electron beam and FEL laser output also will be presented.

  9. Problems in the development of autonomous mobile laser systems based on a cw chemical DF laser

    International Nuclear Information System (INIS)

    Aleksandrov, B P; Bashkin, A S; Beznozdrev, V N; Parfen'ev, M V; Pirogov, N A; Semenov, S N

    2003-01-01

    The problems involved in designing autonomous mobile laser systems based on high-power cw chemical DF lasers, whose mass and size parameters would make it possible to install them on various vehicles, are discussed. The need for mobility of such lasers necessitates special attention to be paid to the quest for ways and means of reducing the mass and size of the main laser systems. The optimisation of the parameters of such lasers is studied for various methods of scaling their systems. A complex approach to analysis of the optical scheme of the laser system is developed. (special issue devoted to the 80th anniversary of academician n g basov's birth)

  10. Vacuum mechatronic laser alignment system on the Nova laser

    International Nuclear Information System (INIS)

    Holliday, M.; Wong, K.; Shelton, R.

    1991-11-01

    The experiments conducted on NOVA are done to investigate inertially confined laser fusion reactions. To this end, the ten beams of the laser are aligned to within 30mm. The target chamber employs a vacuum mechatronic based reticle/target positioning system to accomplish this. It is a five degree-of-freedom chamber resident system, known as the Alignment Aids Positioner or AAP. The AAP aids in beam and diagnostic alignment by accurately positioning a reticle at target chamber center to with 7mm. The AAP system increases target positioning and alignment flexibility and accuracy through the use of a computer controlled multi degree-of-freedom stage assembly. This device uses microstepping DC stepper motors with encoders to achieve closed loop control in a 10 -6 torr vacuum. The AAP has two positioning regimes to move the alignment reticle and do beam alignment. One is course positioning in the Y-Z plane that moves a high resolution stage assembly to target chamber center. The other regime is high resolution movement in the X,Y,Z and q directions. 5 refs., 9 figs

  11. Absence of Bacteria on Coronary Angioplasty Balloons from Unselected Patients

    DEFF Research Database (Denmark)

    Hansen, Gorm Mørk; Nilsson, Martin; Nielsen, Claus Henrik

    2015-01-01

    Periodontitis is a chronic, bacterially-induced inflammatory disease of the tooth-supporting tissues, which may result in transient bacteremia and a systemic inflammatory response. Periodontitis is associated with coronary artery disease independently of established cardiovascular risk factors...... and purification steps, and demonstration of sensitivity levels of 25-125 colony forming units (CFU), we did not detect bacterial DNA from any of the coronary angioplasty balloons. A subsequent questionnaire indicated that the prevalence of periodontitis in the study cohort was at least 39.5%. Although coronary...

  12. Percutaneous angioplasty of carotid artery stenoses

    Energy Technology Data Exchange (ETDEWEB)

    Freitag, G.; Freitag, J.; Koch, R.D.; Wagemann, W.

    1986-03-01

    Percutaneous transluminal angioplasty (PTA) is a well-established method to remedy stenoses and short occlusions in the femoro-popliteal region and has also proved worthwhile in dilating stenoses of pelvic, renal and coronary arteries. Following successful experiments in animals, Mathias et al. employed angioplasty to treat carotid artery stenoses in the same way. To date, successful treatment of carotid artery stenoses has been described only in isolated recent reports. For fear of embolism, angioplasty has not yet become standard practice in this region. Because of the limited number of carotid artery stenoses treated so far, the risk involved cannot be reliably assessed. It is remarkable that no embolism has been reported for the greater number of dilated stenoses of the subclavian artery. Moreover, the report by Mathias et al. indicated that for 350 angioplasties of pelvifemoral arteries 1.1% embolisms occured after artery occlusions only, while no embolism was observed after stenoses. Having gained experience of applying PTA to the treatment of vascular obstructions of extremities, we have adopted this technique in the carotid area as well.

  13. Laser fusion system design study. Final report

    International Nuclear Information System (INIS)

    1975-01-01

    The following studies were completed: (1) The synthesis of a pointing/control system compatible with existing and advanced laser opto-mechanical configurations. (2) Attainment of the required pointing angle, longitudinal focus, and differential pathlength accuracies. (3) Maximum modularization of the sensor and gimbal assemblies to provide the required accuracies at minimum cost. Detailed information is given on each. (MOW)

  14. Electronic Subsystems For Laser Communication System

    Science.gov (United States)

    Long, Catherine; Maruschak, John; Patschke, Robert; Powers, Michael

    1992-01-01

    Electronic subsystems of free-space laser communication system carry digital signals at 650 Mb/s over long distances. Applicable to general optical communications involving transfer of great quantities of data, and transmission and reception of video images of high definition.

  15. MBE System for Antimonide Based Semiconductor Lasers

    National Research Council Canada - National Science Library

    Lester, Luke

    1999-01-01

    .... SLR-770 inductively coupled plasma (ICP) processing system. The SLR-770 has been invaluable in the study of plasma etching of AlGaAsSb and GaSb-materials that form the backbone of antimonide-based semiconductor lasers...

  16. Infrared laser scattering system for the plasma diagnostics

    International Nuclear Information System (INIS)

    Hiraki, Naoji; Kawasaki, Shoji; Muraoka, Katsunori

    1975-01-01

    As the results of the parametric studies of the double discharge TEA CO 2 laser, the required properties on the laser system for the scattering diagnostics of plasmas are shown to be realized with our CO 2 laser. The direction of the future improvements of the laser performance is also discussed. (auth.)

  17. Five Wavelength DFB Fibre Laser Source for WDM Systems

    DEFF Research Database (Denmark)

    Hübner, Jörg; Varming, Poul; Kristensen, Martin

    1997-01-01

    Singlemode UV-induced distributed feedback (DFB) fibre lasers with a linewidth of lasers is verified by a 10 Gbit/s transmission experiment. Five DFB fibre lasers are cascaded and pumped by a single...... semiconductor laser, thereby forming a multiwavelength source for WDM systems...

  18. Evolution of shiva laser alignment systems

    International Nuclear Information System (INIS)

    Boyd, R.D.

    1980-07-01

    The Shiva oscillator pulse is preamplified and divided into twenty beams. Each beam is then amplified, spatially filtered, directed, and focused onto a target a few hundred micrometers in size producing optical intensities up to 10 16 W/cm 2 . The laser was designed and built with three automatic alignment systems: the oscillator alignment system, which aligns each of the laser's three oscillators to a reference beamline; the chain input pointing system, which points each beam into its respective chain; and the chain output pointing, focusing and centering system which points, centers and focuses the beam onto the target. Recently the alignment of the laser's one hundred twenty spatial filter pinholes was also automated. This system uses digitized video images of back-illuminated pinholes and computer analysis to determine current positions. The offset of each current position from a desired center point is then translated into stepper motor commands and the pinhole is moved the proper distance. While motors for one pinhole are moving, the system can digitize, analyze, and send commands to other motors, allowing the system to efficiently align several pinholes in parallel

  19. Recent laser experiments on the Aurora KrF/ICF laser system

    International Nuclear Information System (INIS)

    Turner, T.P.; Jones, J.E.; Czuchlewski, S.J.; Watt, R.G.; Thomas, S.J.; Kang, M.; Tallman, C.R.; Mack, J.M.; Figueira, J.F.

    1990-01-01

    The Aurora KrF/ICF Laser Facility at Los Alamos is operational at the kilojoule-level for both laser and target experiments. We report on recent laser experiments on the system and resulting system improvements. 3 refs., 4 figs

  20. Laser Safety and Hazard Analysis for the Trailer (B70) Based AURA Laser System

    International Nuclear Information System (INIS)

    AUGUSTONI, ARNOLD L.

    2003-01-01

    A laser safety and hazard analysis was performed for the AURA laser system based on the 2000 version of the American National Standards Institute's (ANSI) Standard Z136.1, for ''Safe Use of Lasers'' and the 2000 version of the ANSI Standard Z136.6, for ''Safe Use of Lasers Outdoors''. The trailer based AURA laser system is a mobile platform, which is used to perform laser interaction experiments and tests at various national test sites. The trailer (B70) based AURA laser system is generally operated on the United State Air Force Starfire Optical Range (SOR) at Kirtland Air Force Base (KAFB), New Mexico. The laser is used to perform laser interaction testing inside the laser trailer as well as outside the trailer at target sites located at various distances from the exit telescope. In order to protect personnel, who work inside the Nominal Hazard Zone (NHZ), from hazardous laser emission exposures it was necessary to determine the Maximum Permissible Exposure (MPE) for each laser wavelength (wavelength bands) and calculate the appropriate minimum Optical Density (OD min ) of the laser safety eyewear used by authorized personnel and the Nominal Ocular Hazard Distance (NOHD) to protect unauthorized personnel who may have violated the boundaries of the control area and enter into the laser's NHZ

  1. 21 CFR 884.6200 - Assisted reproduction laser system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Assisted reproduction laser system. 884.6200... (CONTINUED) MEDICAL DEVICES OBSTETRICAL AND GYNECOLOGICAL DEVICES Assisted Reproduction Devices § 884.6200 Assisted reproduction laser system. (a) Identification. The assisted reproduction laser system is a device...

  2. Commercialization plan laser-based decoating systems

    International Nuclear Information System (INIS)

    Freiwald, J.; Freiwald, D.A.

    1998-01-01

    F2 Associates Inc. (F2) is a small, high-technology firm focused on developing and commercializing environmentally friendly laser ablation systems for industrial-rate removal of surface coatings from metals, concrete, and delicate substrates such as composites. F2 has a contract with the US Department of Energy Federal Energy Technology Center (FETC) to develop and test a laser-based technology for removing contaminated paint and other contaminants from concrete and metal surfaces. Task 4.1 in Phase 2 of the Statement of Work for this DOE contract requires that F2 ''document its plans for commercializing and marketing the stationary laser ablation system. This document shall include a discussion of prospects for commercial customers and partners and may require periodic update to reflect changing strategy. This document shall be submitted to the DOE for review.'' This report is being prepared and submitted in fulfillment of that requirement. This report describes the laser-based technology for cleaning and coatings removal, the types of laser-based systems that have been developed by F2 based on this technology, and the various markets that are emerging for this technology. F2's commercialization and marketing plans are described, including how F2's organization is structured to meet the needs of technology commercialization, F2's strategy and marketing approach, and the necessary steps to receive certification for removing paint from aircraft and DOE certification for D and D applications. The future use of the equipment built for the DOE contract is also discussed

  3. Phase Noise Comparision of Short Pulse Laser Systems

    Energy Technology Data Exchange (ETDEWEB)

    S. Zhang; S. V. Benson; J. Hansknecht; D. Hardy; G. Neil; Michelle D. Shinn

    2006-12-01

    This paper describes the phase noise measurement on several different mode-locked laser systems that have completely different gain media and configurations including a multi-kW free-electron laser. We will focus on the state of the art short pulse lasers, especially the drive lasers for photocathode injectors. A comparison between the phase noise of the drive laser pulses, electron bunches and FEL pulses will also be presented.

  4. Method and system for communicating with a laser power driver

    Science.gov (United States)

    Telford, Steven

    2017-07-18

    A system for controlling a plurality of laser diodes includes an optical transmitter coupled to the laser diode driver for each laser diode. An optical signal including bi-phase encoded data is provided to each laser diode driver. The optical signal includes current level and pulse duration information at which each of the diodes is to be driven. Upon receiving a trigger signal, the laser diode drivers operate the laser diodes using the current level and pulse duration information to output a laser beam.

  5. Improving the laser brightness of a commercial laser system

    Science.gov (United States)

    Naidoo, Darryl; Litvin, Igor; Forbes, Andrew

    2016-02-01

    We investigate the selection of a flat-top beam and a Gaussian beam inside a laser cavity on opposing mirrors. The concept is tested external to the laser cavity in a single pass and double pass regime where the latter mimics a single round trip in the laser. We implement this intra-cavity selection through the use of two 16 level diffractive optical elements. We consider a solid-state diode side-pumped laser resonator in a typical commercial laser configuration that consists of two planar mirrors where the DOEs are positioned at the mirrors. We out couple the Gaussian and flat-top distributions and we show that we improve the brightness of the laser with active mode control. We also demonstrate that the quality of the beam transformations determine the brightness improvement.

  6. Angioplasty for Non-arteriosclerotic Renal Artery Stenosis: The Efficacy of Cutting Balloon Angioplasty Versus Conventional Angioplasty

    International Nuclear Information System (INIS)

    Tanaka, Ryoichi; Higashi, Masahiro; Naito, Hiroaki

    2007-01-01

    Purpose. We examined the efficacy of conventional balloon angioplasty and cutting balloon angioplasty (CBA) for the treatment of non-arteriosclerotic renal artery stenosis (RAS). Materials and Methods. From 1993 to 2005, 20 patients underwent 27 percutaneous transluminal renalangioplasty (PTRA) for non-arteriosclerotic RAS (men: 8, women: 12, 25.5 +/- 2 years old; 16 fibromuscular dysplasia (FMD), 4 Takayasu disease). We evaluated the efficacy of CBA by comparing the rate of initial technical success and surgical conversion. Results. Before the clinical authorization of CBA, three of twelve patients (25 %) underwent surgical bypass due to the failure of PTRA due to the hardness of the lesion. After the approval of cutting balloon, we performed CBA in four cases (2 FMD,2 Takayasu disease) to dilate hard lesions, within which a properly sized balloon could not dilate due to their hardness, or to reduce the risk of local dissection. Initial successes were obtained in all patients (8/8, 100%) and none of the patients underwent surgical conversion. Despite of the good initial result, restenosis was observed in three cases within 6 month (3/4, 75 %). Additional interventions were performed in all patients, then, the severity of the restenotic lesion was found not to be exceeded comparing with the initial lesion. Conclusion. The cutting balloon angioplasty may be safe and useful procedure for hard lesions of RAS caused by non-arteriosclerotic disease? especially fibromuscular dysplasia. The cutting balloon may provide the initial success, but the effect on long-term patency is still controversial

  7. Construction of a large laser fusion system

    International Nuclear Information System (INIS)

    Hurley, C.A.

    1977-01-01

    Construction of a large laser fusion machine is nearing completion at the Lawrence Livermore Laboratory (LLL). Shiva, a 20-terawatt neodymium doped glass system, will be complete in early 1978. This system will have the high power needed to demonstrate significant thermonuclear burn. Shiva will irradiate a microscopic D-T pellet with 20 separate laser beams arriving simultaneously at the target. This requires precise alignment, and stability to maintain alignment. Hardware for the 20 laser chains is composed of 140 amplifiers, 100 spatial filters, 80 isolation stages, 40 large turning mirrors, and a front-end splitter system of over 100 parts. These are mounted on a high stability, three dimensional spaceframe which serves as an optical bench. The mechanical design effort, spanning approximately 3 years, followed a classic engineering evolution. The conceptual design phase led directly to system optimization through cost and technical tradeoffs. Additional manpower was then required for detailed design and specification of hardware and fabrication. Design of long-lead items was started early in order to initiate fabrication and assembly while the rest of the design was completed. All components were ready for assembly and construction as fiscal priorities and schedules permitted

  8. Laser fusion systems for industrial process heat. Third semiannual report

    International Nuclear Information System (INIS)

    Bates, F.J.; Denning, R.S.; Dykhuizen, R.C.; Goldthwaite, W.H.; Kok, K.D.; Skelton, J.C.

    1979-01-01

    This report concentrates not only on the design of the laser fusion system but also on the cost of this system and the costs of alternative sources of energy that are expected to be in competition with the laser fusion system. The absolute values of the cost of the laser fusion system are limited by the estimates of the cost of the components and subsystems making up the laser fusion energy station. The method used in calculating costs of the laser fusion and alternative systems are laid out in detail

  9. Laser fusion hybrid reactor systems study

    International Nuclear Information System (INIS)

    1976-07-01

    The work was performed in three phases. The first phase included a review of the many possible laser-reactor-blanket combinations and resulted in the selection of a ''demonstration size'' 500 MWe plant for further study. A number of fast fission blankets using uranium metal, uranium-molybdenum alloy, and uranium carbide as fuel were investigated. The second phase included design of the reactor vessel and internals, heat transfer system, tritium processing system, and the balance of plant, excluding the laser building and equipment. A fuel management scheme was developed, safety considerations were reviewed, and capital and operating costs were estimated. Costs developed during the second phase were unexpectedly high, and a thorough review indicated considerable unit cost savings could be obtained by scaling the plant to a larger size. Accordingly, a third phase was added to the original scope, encompassing the redesign and scaling of the plant from 500 MWe to 1200 MWe

  10. Retrospective study of rapid-exchange monorail versus over-the-wire technique for femoropopliteal angioplasty.

    Science.gov (United States)

    Jahnke, Thomas; Schäfer, Jost Philipp; Bolte, Hendrik; Schäfer, Fritz; Michalek, Jens; Charalambous, Nicholas; Sapoval, Marc; Müller-Hülsbeck, Stefan

    2008-01-01

    The purpose of this study was to compare procedural outcome of rapid-exchange (RX) monorail versus conventional over-the-wire (OTW) technique for femoropopliteal angioplasty. Demographic data, procedure details, angioplasty success, and complications of 328 consecutive percutaneous transluminal angioplasties (PTAs) were collected from a prospective database and retrospectively analyzed. Procedure details included duration of fluoroscopy, area-dose product, amount of contrast agent, sheath sizes, access route, length of stenosis, presence of total occlusion, technical and anatomical success (residual stenosis or = 6 Fr = 82.5% for OTW) but showed only a tendency toward lower overall complication rates (16.6% [17/102] in the RX group versus 19.9% [45/226] in the OTW group; p = 0.09). There was no effect on length of hospitalization. RX monorail systems were not associated with higher procedural costs when compared to conventional OTW technique. We conclude that RX monorail systems seem to enhance the technical success of femoropopliteal angioplasty. Although smaller sheath sizes can be used due to the lower profile of the RX systems, there is only a tendency toward lower complication rates.

  11. System for combining laser beams of diverse frequencies

    International Nuclear Information System (INIS)

    1980-01-01

    A system is described for combining laser beams of different frequencies into a number of beams each comprising laser radiation having components of each of the different frequencies. The system can be used in laser isotope separation facilities. (U.K.)

  12. Laser surveillance systems for fuel storage pools

    International Nuclear Information System (INIS)

    Boeck, H.

    1985-06-01

    A Laser Surveillance System (LASSY) as a new safeguards device has been developed under the IAEA research contract No. 3458/RB at the Atominstitut Wien using earlier results by S. Fiarman. This system is designed to act as a sheet of light covering spent fuel assemblies in spent fuel storage pools. When movement of assemblies takes place, LASSY detects and locates the position of the movement in the pool and when interrogated, presents a list of pool positions and times of movement to the safeguards inspector. A complete prototype system was developed and built. Full scale tests showed the principal working capabilities of a LASSY underwater

  13. Laser control of natural disperse systems

    Science.gov (United States)

    Vlasova, Olga L.; Bezrukova, Alexandra G.

    2003-10-01

    Different water disperse systems were studied by integral (spectroturbidemetry) and differential light scattering method with a laser as a source of light. The investigation done concerns the state of kaolin dispersions at storage and under dilution as an example of mineral dispersion systems such as natural water. The role of some light scattering parameters for an optical analysis of water dispersions, like the dispersion of erythrocytes and bacterial cells -Escherichia coli is discussed. The results obtained can help to elaborate the methods for on-line optical control fo natural disperse systems (water, air) with mineral and biological particles.

  14. Cerebral hyperperfusion syndrome after carotid angioplasty

    International Nuclear Information System (INIS)

    Milosevic, Z.; Surlan, M.; Zvan, B.; Zaletel, M.

    2002-01-01

    Background. Cerebral hyperperfusion syndrome after carotid endarterectomy is an uncommon but well-defined entity. There are only few reports of ''hyperperfusion injury'' following carotid angioplasty. Case report. We report an unstable arterial hypertension and high-grade carotid stenosis in a 58-year-old, right-handed woman. After a stroke in the territory of middle cerebral artery carotid angioplasty was performed in the patient. Among risk factors, the long lasting arterial hypertension was the most pronounced. Immediately after the procedure, the patient was stable without any additional neurologic deficit. The second day, the patient had an epileptic seizure and CT revealed a small haemorrhage in the left frontal lobe. Conclusions. The combination of a high-grade carotid stenosis and unstable arterial pressure is probably an important prognostic factor in the pathogenesis of hyperperfusion syndrome. (author)

  15. Mode-Locked Semiconductor Lasers for Optical Communication Systems

    DEFF Research Database (Denmark)

    Yvind, Kresten; Larsson, David; Oxenløwe, Leif Katsuo

    2005-01-01

    We present investigations on 10 and 40 GHz monolithic mode-locked lasers for applications in optical communications systems. New all-active lasers with one to three quantum wells have been designed, fabricated and characterized....

  16. Laser experimental system as teaching aid for demonstrating basic phenomena of laser feedback

    International Nuclear Information System (INIS)

    Xu, Ling; Zhao, Shijie; Zhang, Shulian

    2015-01-01

    An experimental laser teaching system is developed to demonstrate laser feedback phenomena, which bring great harm to optical communication and benefits to precision measurement. The system consists of an orthogonally polarized He-Ne laser, a feedback mirror which reflects the laser output light into the laser cavity, and an optical attenuator which changes the intensity of the feedback light. As the feedback mirror is driven by a piezoelectric ceramic, the attenuator is adjusted and the feedback mirror is tilted, the system can demonstrate many basic laser feedback phenomena, including weak, moderate and strong optical feedback, multiple feedback and polarization flipping. Demonstrations of these phenomena can give students a better understanding about the intensity and polarization of lasers. The system is well designed and assembled, simple to operate, and provides a valuable teaching aid at an undergraduate level. (paper)

  17. Synchronised laser chaos communication: statistical investigation of an experimental system

    OpenAIRE

    Lawrance, Anthony J.; Papamarkou, Theodore; Uchida, Atsushi

    2017-01-01

    The paper is concerned with analyzing data from an experimental antipodal laser-based chaos shift-keying communication system. Binary messages are embedded in a chaotically behaving laser wave which is transmitted through a fiber-optic cable and are decoded at the receiver using a second laser synchronized with the emitter laser. Instrumentation in the experimental system makes it particularly interesting to be able to empirically analyze both optical noise and synchronization error as well a...

  18. Lasers in tattoo and pigmentation control: role of the PicoSure(®) laser system.

    Science.gov (United States)

    Torbeck, Richard; Bankowski, Richard; Henize, Sarah; Saedi, Nazanin

    2016-01-01

    The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure(®) laser system (755/532 nm). Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure(®) laser system for tattoo removal. A PubMed search was conducted using the term "picosecond" combined with "laser", "dermatology", and "laser tattoo removal". A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow). Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change. Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure(®) laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments.

  19. Retrospective Study of Rapid-Exchange Monorail Versus Over-the-Wire Technique for Femoropopliteal Angioplasty

    International Nuclear Information System (INIS)

    Jahnke, Thomas; Schaefer, Jost Philipp; Bolte, Hendrik; Schaefer, Fritz; Michalek, Jens; Charalambous, Nicholas; Sapoval, Marc; Mueller-Huelsbeck, Stefan

    2008-01-01

    PurposeThe purpose of this study was to compare procedural outcome of rapid-exchange (RX) monorail versus conventional over-the-wire (OTW) technique for femoropopliteal angioplasty.Materials and MethodsDemographic data, procedure details, angioplasty success, and complications of 328 consecutive percutaneous transluminal angioplasties (PTAs) were collected from a prospective database and retrospectively analyzed. Procedure details included duration of fluoroscopy, area-dose product, amount of contrast agent, sheath sizes, access route, length of stenosis, presence of total occlusion, technical and anatomical success (residual stenosis <30% in the absence of complications), need for bail-out stenting, and periprocedural complications. The RX technique alone was used in 102 of 328 cases (31%); the OTW technique, in 226 of 328 of cases (68%).ResultsTechnical success was 98% for the RX versus 95.4% for the OTW technique (p = 0.2). A significantly greater number of stents had to be implanted due to angioplasty failure when the OTW technique was used (RX, 5.9%; OTW, 13.7%; p = 0.04). There were no significant differences in fluorocopy time, dose-area product, or amount of contrast medium used. The RX system facilitated the use of smaller sheath sizes (5 Fr = 38% and 6 Fr = 59% for RX versus 5 Fr = 16.8% and ≥6 Fr = 82.5% for OTW) but showed only a tendency toward lower overall complication rates (16.6% [17/102] in the RX group versus 19.9% [45/226] in the OTW group; p = 0.09). There was no effect on length of hospitalization. RX monorail systems were not associated with higher procedural costs when compared to conventional OTW technique.ConclusionWe conclude that RX monorail systems seem to enhance the technical success of femoropopliteal angioplasty. Although smaller sheath sizes can be used due to the lower profile of the RX systems, there is only a tendency toward lower complication rates.

  20. Comparison of three different laser systems for application in dentistry

    Science.gov (United States)

    Mindermann, Anja; Niemz, M. H.; Eisenmann, L.; Loesel, Frieder H.; Bille, Josef F.

    1993-12-01

    Three different laser systems have been investigated according to their possible application in dentistry: a free running and a Q-switched microsecond Ho:YAG laser, a free running microsecond Er:YAG laser and picosecond Nd:YLF laser system consisting of an actively mode locked oscillator and a regenerative amplifier. The experiments focused on the question if lasers can support or maybe replace ordinary drilling machines. For this purpose several cavities were generated with the lasers mentioned above. Their depth and quality were judged by light and electron microscopy. The results of the experiments showed that the picosecond Nd:YLF laser system has advantages compared to other lasers regarding their application in dentistry.

  1. Laser-start-up system for magnetic mirror fusion

    International Nuclear Information System (INIS)

    Frank, A.M.; Thomas, S.R.; Denhoy, B.S.; Chargin, A.K.

    1976-01-01

    A CO 2 laser system has been developed at LLL to provide hot start-up plasmas for magnetic mirror fusion experiments. A frozen ammonia pellet is irradiated with a laser power density in excess of 10 13 W/cm 2 in a 50-ns pulse. This system uses commercially available laser systems. Optical components were fabricated both by direct machining and standard techniques. The technologies used in this system are directly applicable to reactor scale systems

  2. Laser cutting system in bridge fabricating line; Kyoryo seisaku line ni okeru laser no setsudan system

    Energy Technology Data Exchange (ETDEWEB)

    Kitaguchi, Y.; Yokotani, K. [Hitachi Zosen Corp., Osaka (Japan)

    1994-11-01

    This paper describes the laser cutting system established at a new advanced plant that was constructed by Hitachi Shipbuilding and Engineering Co., Ltd. in 1993. At the plant, the cutting line consists of four NC cutting lines: the plasma cutting machine, gas cutting machine, frame planer, and laser cutting machine. The laser cutting machine is used to cut complex shapes of relatively thin (6 - 16 mm) materials with high accuracy. The machine consists of a 3 kW CO2 laser oscillator mounted gantry type NC cutter and a slat conveyor of about 30 m long, with the maximum cutting width of 3.6 m. The NC cutting machine is provided with the automatic printing function using NC data, marking function, scheduled operation function, steel plate detector, and coordinate rotation function, etc. These functions enable unattended operation of the machine to cut multiple materials. This NC laser cutting line has the same performance data collection function for data during the operating time as other production lines. Therefore, the NC laser cutting line can be subjected to the realtime centralized control together with the other lines. All these technologies have provided high accuracy and efficiency for production as well as an environment in which many female operators can successfully work. 10 figs., 4 tabs.

  3. Diode-laser-illuminated automotive lamp systems

    Science.gov (United States)

    Marinelli, Michael A.; Remillard, Jeffrey T.

    1998-05-01

    We have utilized the high brightness of state-of-the-art diode laser sources, and a variety of emerging optical technologies to develop a new class of thin, uniquely styled automotive brake and signal lamps. Using optics based on thin (5 mm) plastic sheets, these lamps provide appearance and functional advantages not attainable with traditional automotive lighting systems. The light is coupled into the sheets using a 1 mm diameter glass fiber, and manipulated using refraction and reflection from edges, surfaces, and shaped cut-outs. Light can be extracted with an efficiency of approximately 50% and formed into a luminance distribution that meets the Society of Automotive Engineers (SAE) photometric requirements. Prototype lamps using these optics have been constructed and are less than one inch in thickness. Thin lamps reduce sheet metal costs, complexity, material usage, weight, and allow for increased trunk volume. In addition, these optics enhance lamp design flexibility. When the lamps are not energized, they can appear body colored, and when lighted, the brightness distribution across the lamp can be uniform or structured. A diode laser based brake lamp consumes seven times less electrical power than one using an incandescent source and has instant on capability. Also, diode lasers have the potential to be 10-year/150,000 mile light sources.

  4. Long life gas laser system and method

    International Nuclear Information System (INIS)

    Hochuli, E.E.

    1975-01-01

    A long life gas discharge laser having an improved self-repairing cathode system is described. In a specific embodiment, water vapor having a partial pressure below about 10 -5 torr incorporated in a molecular sieve is used to provide impurities (in this case water vapor) for repairing the cathode surface by regenerating the oxide surface and/or preventing same from deteriorating. Other impurities may be incorporated in the molecular sieve such as hydrogen, oxygen, for example. In some cases CO 2 may be used. This application includes material disclosed in a paper entitled ''Continuation of the Investigation into Material Properties Affecting the Frequency Stability and Reliability of He-Ne Laser Structures'' submitted to the Office of Naval Research dated June 1972 by the inventor hereof and also a paper entitled ''Investigations of the Long Term Frequency Stability of Stable Laser Structures'' Progress Report for ONR Contract N00014-67-A-D239-0016 July 1972 by the inventor hereof. A royalty free license is hereby granted to the United States for use of the invention for all government purposes. (auth)

  5. Energy storage and power conditioning system for the Shiva laser

    International Nuclear Information System (INIS)

    Allen, G.R.; Gagnon, W.L.; Rupert, P.R.; Trenholme, J.B.

    1975-01-01

    An optimal energy delivery system for the world's largest glass laser system has been designed based on computer modeling and operation of laser hardware. Components of the system have been tested on operating lasers at LLL. The Shiva system is now under construction and will be completed in 1977. The energy supply described here will provide cost-effective, reliable power and facilitate the gathering of data in pursuit of controlled thermonuclear reactions

  6. Development of AVLIS dye laser system

    International Nuclear Information System (INIS)

    Sugiyama, Akira; Nakayama, Tsuyoshi; Kato, Masaaki; Arisawa, Takashi

    1995-01-01

    CVL pumped single mode dye laser was performed. It was found that pressure tuning has some excellent feature in comparison to mechanical tuning in dye laser frequency control. For evaluation of dye laser amplifier, two-dimensional rate equation was proposed. Calculated data by this equation agreed with experimental data in large diameter input dye laser beam condition. (author)

  7. CONFOCAL MICROSCOPY SYSTEM PERFORMANCE: LASER POWER MEASUREMENTS

    Science.gov (United States)

    Laser power abstract The reliability of the confocal laser-scanning microscope (CLSM) to obtain intensity measurements and quantify fluorescence data is dependent on using a correctly aligned machine that contains a stable laser power. The laser power test appears to be one ...

  8. Recent laser physics results on power balance and frequency conversion with the Phebus laser system

    International Nuclear Information System (INIS)

    Thiell, G.; Paye, J.; Graillot, H.; Mathieu, F.; Boscheron, A.; Reynier, F.; Estraillier, P.; Bruneau, J.L.

    1995-01-01

    The Phebus laser system has been mainly devoted to plasma physics experiments such as implosion and hydrodynamical instability studies since it was completed in 1985. But during the last two years, the three Phebus beamlines (2 main beams and a backlighter beam) are also utilized to perform some laser physics studies in view of the Megajoule laser project. The goal of the laser physics experiments conducted at the Phebus facility in 1994--1995 is to validate some design issues of the Megajoule Laser project concerning namely power balance and frequency conversion

  9. Lasers and power systems for inertial confinement fusion reactors

    International Nuclear Information System (INIS)

    Stark, E.E. Jr.

    1978-01-01

    After discussing the role of lasers in ICF and the candidate lasers, several important areas of technology requirements are discussed. These include the beam transport system, the pulsed power system and the gas flow system. The system requirements, state of the art, as well as needs and prospects for new technology developments are given. Other technology issues and promising developments are described briefly

  10. Development of YAG laser cutting system for decommissioning nuclear equipments

    International Nuclear Information System (INIS)

    Kasai, Takeshi; Nitta, Kazuhiko; Hosoda, Hiroshi.

    1995-01-01

    Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. As a result, the stainless steel plate with a thickness of 22mm could be cut by using an optical fiber which can flexibly propagate laser power, and possibility of application of this laser cutting system to decommissioning nuclear equipments was verified. (author)

  11. Development of YAG laser cutting system for decommissioning nuclear equipments

    Energy Technology Data Exchange (ETDEWEB)

    Kasai, Takeshi [Fuji Electric Co. Research and Development Ltd., Yokosuka, Kanagawa (Japan); Nitta, Kazuhiko; Hosoda, Hiroshi

    1995-07-01

    Technology of remote controlled cutting and reduction of generative secondary products have been required to the cutting system for decommissioning nuclear equipments. At a point of view that laser cutting technology by use of a Nd:YAG laser is effective, we have developed the laser cutting machine and carried out cutting tests for several stainless steel plates. As a result, the stainless steel plate with a thickness of 22mm could be cut by using an optical fiber which can flexibly propagate laser power, and possibility of application of this laser cutting system to decommissioning nuclear equipments was verified. (author).

  12. Laser system for a subpicosecond electron linac

    International Nuclear Information System (INIS)

    Crowell, R. A.

    1998-01-01

    At the Argonne Chemistry Division efforts are underway to develop a sub-picosecond electron beam pulse radiolysis facility for chemical studies. The target output of the accelerator is to generate electron pulses that can be adjusted from 3nC in .6ps to 100nC in 45ps. In conjunction with development of the accelerator a state-of-the-art ultrafast laser system is under construction that will drive the linac's photocathode and provide probe pulses that are tunable from the UV to IR spectral regions

  13. Coronary stenting as an adjunct to balloon angioplasty

    NARCIS (Netherlands)

    B.H. Strauss (Bradley)

    1991-01-01

    textabstractAndreas Gruentzig initiated the era of interventional cardiology in 19n with the introduction of percutaneous transluminal coronary angioplasty (PTCA) (1). The acceptance of coronary angioplasty is obvious by the widespread use of the procedure (>300,000 cases in the United States in

  14. Cost analysis of lasers for a laser isotope separation system. Final report

    International Nuclear Information System (INIS)

    Mail, R.A.; Markovich, F.J.; Carr, R.H.

    1977-01-01

    To be of practical significance, laser isotope separation (LIS) for separation of 235 U from 238 U must exhibit attributes which make it preferable to expansion of the present facilities. Clearly the most attractive such attribute is the prospect of significant cost reductions, which preliminary studies at LLL suggest will amount to a factor of three and perhaps as much as ten. From these preliminary studies, it appears that the lasers themselves account for a very substantial portion of the capital cost of a LIS system, and a significant portion of the equipment replacement costs. Since the laser costs are so pivotal to the system cost, and the system cost is so pivotal to the choice of separation techniques, it is clear that a more detailed investigation of laser costs is required. Results are presented of a study performed by General Research Corporation (GRC) to assess the cost of lasers in a production laser isotope separation (LIS) plant

  15. High power laser downhole cutting tools and systems

    Science.gov (United States)

    Zediker, Mark S; Rinzler, Charles C; Faircloth, Brian O; Koblick, Yeshaya; Moxley, Joel F

    2015-01-20

    Downhole cutting systems, devices and methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena. Systems and devices for the laser cutting operations within a borehole in the earth. These systems and devices can deliver high power laser energy down a deep borehole, while maintaining the high power to perform cutting operations in such boreholes deep within the earth.

  16. OCT evaluation of directional atherectomy compared to balloon angioplasty

    International Nuclear Information System (INIS)

    Marmagkiolis, Konstantinos; Lendel, Vasili; Cilingiroglu, Mehmet

    2015-01-01

    Directional atherectomy (DA) is one of the most commonly used modalities for the treatment of obstructive femoropopliteal peripheral arterial disease (PAD), especially in patients with large and calcified atherosclerotic plaques. The effect of directional atherectomy to the vascular wall compared to balloon angioplasty by optical coherence tomography (OCT) has not been previously described. We present the first case of OCT after directional atherectomy with SilverHawk followed by angiosculpt balloon angioplasty. - Highlights: • Directional atherectomy avoids the vascular mechanical damage caused by angioplasty balloons and the exposure of stent struts or the potential of stent fracture with stents. • OCT can accurately assess the effect of endovacular interventions to the vessel wall. • Although angiographic results after directional atherectomy are acceptable, OCT use demonstrated suboptimal improvement of the MLA requiring additional balloon angioplasty. • Longer studies are needed to define whether the improved OCT results with angioplasty compared to DA may offer better clinical outcomes.

  17. OCT evaluation of directional atherectomy compared to balloon angioplasty

    Energy Technology Data Exchange (ETDEWEB)

    Marmagkiolis, Konstantinos [Citizens Memorial Hospital Heart and Vascular Institute, Bolivar, MO (United States); Lendel, Vasili [Arkansas Heart Hospital, Peripheral Vascular Institute, Little Rock, AR (United States); Cilingiroglu, Mehmet, E-mail: mcilingiroglu@yahoo.com [Arkansas Heart Hospital, Peripheral Vascular Institute, Little Rock, AR (United States); Koc University, School of Medicine, Istanbul (Turkey)

    2015-09-15

    Directional atherectomy (DA) is one of the most commonly used modalities for the treatment of obstructive femoropopliteal peripheral arterial disease (PAD), especially in patients with large and calcified atherosclerotic plaques. The effect of directional atherectomy to the vascular wall compared to balloon angioplasty by optical coherence tomography (OCT) has not been previously described. We present the first case of OCT after directional atherectomy with SilverHawk followed by angiosculpt balloon angioplasty. - Highlights: • Directional atherectomy avoids the vascular mechanical damage caused by angioplasty balloons and the exposure of stent struts or the potential of stent fracture with stents. • OCT can accurately assess the effect of endovacular interventions to the vessel wall. • Although angiographic results after directional atherectomy are acceptable, OCT use demonstrated suboptimal improvement of the MLA requiring additional balloon angioplasty. • Longer studies are needed to define whether the improved OCT results with angioplasty compared to DA may offer better clinical outcomes.

  18. Carotid angioplasty and stenting in the elderly

    International Nuclear Information System (INIS)

    Kadkhodayan, Yasha; Cross, DeWitte T.; Moran, Christopher J.; Derdeyn, Colin P.

    2007-01-01

    To investigate the technical success rate as well as the procedural and mid-term complication rates of carotid angioplasty and stenting in elderly patients, a group excluded from large randomized endarterectomy trials given their perceived high surgical risk. Of 200 consecutive carotid angioplasty and/or stenting procedures performed between March 1996 and March 2005, 21 procedures were performed without cerebral protection devices in 20 patients over the age of 79 years (mean age: 83 years, 12 men, eight women). These patients' medical records were retrospectively reviewed for vascular imaging reports and available clinical follow-up. Procedural and mid-term complication rates were calculated and compared to a previously published cohort of 133 consecutive patients ≤79 years of age who also underwent endovascular treatment at our institution. Carotid stenosis was reduced from a mean of 82% to no significant stenosis in all procedures. The procedural stroke rate was zero of 21 procedures. The procedural transient ischemic attack rate (TIA) was one of 21 procedures (4.8%). Mean follow-up was 24.6 months (range: 1.0-79.5 months) with at least a 30-day follow-up for 20 of the 21 procedures (95.2%). There were no new strokes. There was one recurrent ipsilateral TIA at 1.9 months. In five cases with follow-up carotid ultrasonography, no hemodynamically significant restenosis had occurred. There were three myocardial infarctions (MI) occurring at 0.5, 2.1, and 15.2 months, of which the last MI was fatal. The composite 30-day stroke and death rate was zero of 21 procedures (95% confidence interval: 0-14%). No significant difference was found in the 30-day rate of stroke, TIA, MI, or death between the elderly and younger patients. Carotid angioplasty and stenting in elderly patients can be performed successfully with acceptable procedural and mid-term complication rates comparable to younger patients. (orig.)

  19. Stability design considerations for mirror support systems in ICF lasers

    International Nuclear Information System (INIS)

    Tietbohl, G.L.; Sommer, S.C.

    1996-10-01

    Some of the major components of laser systems used for Inertial Confinement Fusion (ICF) are the large aperture mirrors which direct the path of the laser. These mirrors are typically supported by systems which consist of mirror mounts, mirror enclosures, superstructures, and foundations. Stability design considerations for the support systems of large aperture mirrors have been developed based on the experience of designing and evaluating similar systems at the Lawrence Livermore National Laboratory (LLNL). Examples of the systems developed at LLNL include Nova, the Petawatt laser, Beamlet, and the National Ignition Facility (NIF). The structural design of support systems of large aperture mirrors has typically been controlled by stability considerations in order for the large laser system to meet its performance requirements for alignment and positioning. This paper will discuss the influence of stability considerations and will provide guidance on the structural design and evaluation of mirror support systems in ICF lasers so that this information can be used on similar systems

  20. Fluorescence-pumped photolytic gas laser system for a commercial laser fusion power plant

    International Nuclear Information System (INIS)

    Monsler, M.J.

    1977-01-01

    The first results are given for the conceptual design of a short-wavelength gas laser system suitable for use as a driver (high average power ignition source) for a commercial laser fusion power plant. A comparison of projected overall system efficiencies of photolytically excited oxygen, sulfur, selenium and iodine lasers is described, using a unique windowless laser cavity geometry which will allow scaling of single amplifier modules to 125 kJ per aperture for 1 ns pulses. On the basis of highest projected overall efficiency, a selenium laser is chosen for a conceptual power plant fusion laser system. This laser operates on the 489 nm transauroral transition of selenium, excited by photolytic dissociation of COSe by ultraviolet fluorescence radiation. Power balances and relative costs for optics, electrical power conditioning and flow conditioning of both the laser and fluorescer gas streams are discussed for a system with the following characteristics: 8 operating modules, 2 standby modules, 125 kJ per module, 1.4 pulses per second, 1.4 MW total average power. The technical issues of scaling visible and near-infrared photolytic gas laser systems to this size are discussed

  1. Primary coronary angioplasty in a nonagenarian

    Directory of Open Access Journals (Sweden)

    Baracioli Luciano M.

    2002-01-01

    Full Text Available A woman aged 98 years entered the tertiary hospital service with a picture of acute myocardial infarction of the extensive anterior wall, which began 4 hours earlier. Due to the large myocardial risk area suggested by the electrocardiogram, the patient was taken to the hemodynamics laboratory for the performance of emergency coronary arteriography, which revealed occlusion in the proximal third of the anterior descending artery. Primary angioplasty followed by stent grafting was successfully performed. The patient had a satisfactory evolution (Killip I and was discharged from the hospital on the seventh postinfarction day. We discuss here aspects of thrombolysis and coronary percutaneous interventions in the aged.

  2. Treatment of renovascular hypertension by transluminal angioplasty

    DEFF Research Database (Denmark)

    Øvrehus, Kristian A; Andersen, Poul E; Jacobsen, Ib A

    2007-01-01

    : with improved control of blood pressure; group III: unchanged blood pressure control. Grouping was performed immediately after treatment, at 1 month, 6 months and at the latest follow-up. One hundred-and-twenty-two patients (124 atherosclerotic and 12 fibromuscular lesions) were treated during 13 years......OBJECTIVE: The study is a follow-up on treatment of renovascular hypertension (RVH) with percutaneous transluminal renal angioplasty (PTRA). METHODS: Patients were screened on the basis of clinical criteria of increased probability of RVH with renography and in selected cases with renal vein renin...

  3. Thalamic hemorrhage following carotid angioplasty and stenting

    International Nuclear Information System (INIS)

    Friedman, Jonathan A.; Kallmes, David F.; Wijdicks, Eelco F.M.

    2004-01-01

    Carotid angioplasty and stenting (CAS) has emerged as an alternative treatment of carotid stenosis for patients poorly suited for endarterectomy. Intracerebral hemorrhage following carotid revascularization is rare and thought to be related to hyperperfusion injury in most cases. Early experience suggests an increased incidence of hemorrhage following CAS as compared to endarterectomy. We describe a patient who suffered a thalamic hemorrhage following CAS. Because this hemorrhage occurred in a vascular territory unlikely to have been supplied by the treated artery, this case suggests that the mechanism of intracerebral hemorrhage following CAS may in some cases be different from the hyperperfusion hemorrhage classically described following endarterectomy. (orig.)

  4. Percutaneous transluminal angioplasty (PTA) after kidney transplantation

    International Nuclear Information System (INIS)

    Fava, C.; Grosso, M.; Sandrone, M.; Malfi, B.; Segoloni, G.P.; Colla, L.

    1988-01-01

    Renal artery stenosis is a frequent complication of kidney transplantation (10%). Percutaneous transluminal angioplasty (PTA) has recently been proposed as a potential therapeutic procedure. Twelve transplant patients with arterial stenosis underwent PTA. The procedure was successful in 10 cases (83.3%). Restenosis occurred in 2 patients (16.7%); both of them underwent PTA successfully. No complications occurred. A considerable improvement in glomerular filtration rate and a reduction in high blood pressure were observed in all patients after successful PTA. The authors belive PTA to be the therapy of choice in the treatment of arterial stenoses in kidney transplant patients

  5. A novel diode laser system for photodynamic therapy

    DEFF Research Database (Denmark)

    Samsøe, E.; Andersen, P. E.; Petersen, P.

    2001-01-01

    In this paper a novel diode laser system for photodynamic therapy is demonstrated. The system is based on linear spatial filtering and optical phase conjugate feedback from a photorefractive BaTiO3 crystal. The spatial coherence properties of the diode laser are significantly improved. The system...

  6. Lasers in tattoo and pigmentation control: role of the PicoSure® laser system

    Directory of Open Access Journals (Sweden)

    Torbeck R

    2016-05-01

    Full Text Available Richard Torbeck,1 Richard Bankowski,2 Sarah Henize,3 Nazanin Saedi,11Department of Dermatology and Cutaneous Biology, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, 2Cynosure, Inc, Westford, MA, 3Huron Consulting Group, Chicago, IL, USABackground and objectives: The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure® laser system (755/532 nm. Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure® laser system for tattoo removal.Study design and methods: A PubMed search was conducted using the term "picosecond" combined with "laser", "dermatology", and "laser tattoo removal".Results: A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow. Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change.Conclusion: Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure® laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments.Keywords: tattoo, removal, laser, picosecond 

  7. Flow motion waves with high and low frequency in severe ischaemia before and after percutaneous transluminal angioplasty

    OpenAIRE

    Hoffmann, Ulrich; Schneider, Ernst; Bollinger, Alfred

    2017-01-01

    Study of objective - The aim was to evaluate skin flux and prevalence of low and high frequency flow motion waves in patients with severe ischaemia due to peripheral arterial occlusive disease before and after percutaneous transluminal angioplasty (PTA) with and without local thrombolysis. Design - Flow motion was recorded by the laser Doppler technique at the dorsum of the foot before, one day, and one month after PTA. The results were separately analysed in patients with successful and unsu...

  8. Adaptive High Frequency Laser Sonar System

    National Research Council Canada - National Science Library

    Cray, Benjamin A

    2007-01-01

    .... Antivibration mounts are joined between said scanning laser vibrometer and said housing. In further embodiments, the scanning laser vibrometer detects vibrations at a plurality of locations on the acoustic window forming a virtual array...

  9. Feedback stabilization system for pulsed single longitudinal mode tunable lasers

    Science.gov (United States)

    Esherick, Peter; Raymond, Thomas D.

    1991-10-01

    A feedback stabilization system for pulse single longitudinal mode tunable lasers having an excited laser medium contained within an adjustable length cavity and producing a laser beam through the use of an internal dispersive element, including detection of angular deviation in the output laser beam resulting from detuning between the cavity mode frequency and the passband of the internal dispersive element, and generating an error signal based thereon. The error signal can be integrated and amplified and then applied as a correcting signal to a piezoelectric transducer mounted on a mirror of the laser cavity for controlling the cavity length.

  10. Optical laser systems at the Linac Coherent Light Source

    Energy Technology Data Exchange (ETDEWEB)

    Minitti, Michael P.; Robinson, Joseph S.; Coffee, Ryan N.; Edstrom, Steve; Gilevich, Sasha; Glownia, James M.; Granados, Eduardo; Hering, Philippe; Hoffmann, Matthias C.; Miahnahri, Alan; Milathianaki, Despina; Polzin, Wayne; Ratner, Daniel; Tavella, Franz; Vetter, Sharon; Welch, Marc; White, William E.; Fry, Alan R., E-mail: alanfry@slac.stanford.edu [Linac Coherent Light Source, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025 (United States)

    2015-04-22

    This manuscript serves as a reference to describe the optical laser sources and capabilities at the Linac Coherent Light Source. Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump–probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump–probe experiments to be performed at LCLS.

  11. Optical fiber sensor for the detection of laser-generated ultrasound in arterial tissues

    Science.gov (United States)

    Beard, Paul C.; Mills, Timothy N.

    1995-02-01

    Theoretical and experimental aspects of an extrinsic Fabry-Perot optical fiber ultrasound sensor for use in a photoacoustic-guided laser angioplasty system are described. The sensor has been characterized using laser generated thermoelastic waves as a source of wideband ultrasound. A system sensitivity of 25 mV/MPa and an acoustic noise floor of 2 Pa/Hz1/2 are reported using a transparent polymer film as the sensing element. The system demonstrates the required bandwidth for sensing thermoelastic waves containing frequency components up to 20 MHz.

  12. METHOD AND SYSTEM FOR LASER WELDING

    DEFF Research Database (Denmark)

    2008-01-01

    The invention relates to laser welding of at least two adjacent, abutting or overlapping work pieces in a welding direction using multiple laser beams guided to a welding region, wherein at least two of the multiple laser beams are coupled into the welding region so as to form a melt and at least...

  13. Laser-GMA Hybrid Pipe Welding System

    Science.gov (United States)

    2007-11-01

    Investigation of varying laser power. The welded pipe is shown, with close -ups of the rootside reinforcement and macro sections...68 Figure 44. Investigation of varying laser stand-off. The welded pipe is shown, along with close -ups of backside...conventional beveled joints. With appropriate joint configuration and preparation, deep keyhole penetration provided by the laser and additional filler

  14. Chaotic dynamics and chaos control in nonlinear laser systems

    International Nuclear Information System (INIS)

    Fang Jinqing; Yao Weiguang

    2001-01-01

    Chaotic dynamics and chaos control have become a great challenge in nonlinear laser systems and its advances are reviewed mainly based on the ring cavity laser systems. The principle and stability conditions for time-delay feedback control are analyzed and applied to chaos control in the laser systems. Other advanced methods of chaos control, such as weak spatial perturbation and occasional proportional feedback technique, are discussed. Prospects of chaos control for application (such as improvement of laser power and performance, synchronized chaos secure communication and information processing) are pointed out finally

  15. Development of the power control system for semiconductor lasers

    International Nuclear Information System (INIS)

    Kim, Kwang Suk; Kim, Cheol Jung

    1997-12-01

    For the first year plan of this program, we developed the power control system for semiconductor lasers. We applied the high-current switching mode techniques to fabricating a power control system. Then, we investigated the direct side pumping techniques with GaA1As diode laser bars to laser crystal without pumping optics. We obtained 0.5W average output power from this DPSSL. (author). 54 refs., 3 tabs., 18 figs

  16. Modematic: a fast laser beam analyzing system for high power CO2-laser beams

    Science.gov (United States)

    Olsen, Flemming O.; Ulrich, Dan

    2003-03-01

    The performance of an industrial laser is very much depending upon the characteristics of the laser beam. The ISO standards 11146 and 11154 describing test methods for laser beam parameters have been approved. To implement these methods in industry is difficult and especially for the infrared laser sources, such as the CO2-laser, the availabl analyzing systems are slow, difficult to apply and having limited reliability due to the nature of the detection methods. In an EUREKA-project the goal was defined to develop a laser beam analyzing system dedicated to high power CO2-lasers, which could fulfill the demands for an entire analyzing system, automating the time consuming pre-alignment and beam conditioning work required before a beam mode analyses, automating the analyzing sequences and data analysis required to determine the laser beam caustics and last but not least to deliver reliable close to real time data to the operator. The results of this project work will be described in this paper. The research project has led to the development of the Modematic laser beam analyzer, which is ready for the market.

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

    DEFF Research Database (Denmark)

    Müller, André

    propagation parameters and therefore efficiently increases the brightness of compact and cost-effective diode laser systems. The condition of overlapping beams is an ideal scenario for subsequent frequency conversion. Based on sum-frequency generation of two beam combined diode lasers a 3.2 fold increase...... 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....... Implementing the developed concept of frequency converted, beam combined diode laser systems will help to overcome the high pump thresholds for ultrabroad bandwidth titanium sapphire lasers, leading towards diode based high-resolution optical coherence tomography with enhanced image quality. In their entirety...

  18. [Experimental ultrasound angioplasty: in vitro resolution of thrombi].

    Science.gov (United States)

    Stähr, P; Erbel, R; Weber, W; Fischer, H; Meyer, J

    1995-05-01

    A new ultrasonic angioplasty ablation catheter connected to a 19.5 kHz. 25 W transducer was tested in vitro for its ability to disrupt 12-h. 24-h, and 5-day-old whole blood thrombi (n = 45.697 mg +/- 223 mg) and fibrin thrombi (n = 45.338 mg +/- 133 mg), as well as 5-day-old cadaver thrombi (n = 8.270 mg +/- 71 mg) within 10 min. Five of each age were used as control thrombi in which the catheter was moved back and forth without ultrasound emission. The size of ablated thrombus particles was measured by a laser device. The power output at the end of the catheter was assessed calorimetrically. The loss of weight of whole blood thrombi was between 429 (74%) and 524 mg (91%) (p power output at the catheter tip was 5.9 W compared to the power output of 25 W at the ultrasound generator.(ABSTRACT TRUNCATED AT 250 WORDS)

  19. [Synchronized anterograde perfusion during percutaneous transluminal coronary angioplasty: preliminary clinical study].

    Science.gov (United States)

    Farcot, J C; Berland, J; Derumeaux, G; Letac, B; Bourdarias, J P

    1995-03-01

    A new circulatory system, "physiologic anteroperfusion system", has been developed and tested in 6 patients with significant proximal coronary artery stenosis. Prolonged and safe balloon inflation was possible without any ischemic signs. The system consists of an electronic cardiac synchroperfusor which, by activating a pulsatile unit, permits increased diastolic anteroperfusion of autologous blood under physiologic pressure through low-profile standard angioplasty catheters. This study reports the results obtained in 6 patients during proximal prolonged percutaneous transluminal coronary angioplasty. Four men and two women suffering from severe exertional angina pectoris, with normal resting left ventricular function, no collaterals and excellent apical two-dimensional four-chamber echocardiographic views were studied. After a 90 +/- 10 seconds of control occlusion under continuous monitoring of hemodynamics, electrocardiograms (3 to 4 leads), two-dimensional echo and chest pain grading, a second balloon inflation protected by the physiologic anteroperfusion system at a flow rate of 44 +/- 12 ml/min was performed for fifteen minutes. The ischemic signs present in the myocardium depending on the occluded artery were totally abolished during prolonged inflation protected by physiologic anteroperfusion system. All the patients were successfully dilated and were discharged from hospital the following morning without cardiac enzyme elevation or signs of central or peripheral hemolysis. Conclusion, in 6 patients with severe proximal coronary artery stenosis, safe prolonged proximal angioplasty without signs of ischemia was performed using a new simple physiologic anteroperfusion system, which allows active diastolic flow-pressure controlled autologous arterial blood perfusion, through standard low profile catheters.

  20. New laser system for highly sensitive clinical pulse oximetry

    Science.gov (United States)

    Hamza, Mostafa; Hamza, Mohammad

    1996-04-01

    This paper describes the theory and design of a new pulse oximeter in which laser diodes and other compact laser sources are used for the measurement of oxygen saturation in patients who are at risk of developing hypoxemia. The technique depends upon illuminating special sites of the skin of the patient with radiation from modulated laser sources at selected wavelengths. The specific laser wavelengths are chosen based on the absorption characteristics of oxyhemoglobin, reduced hemoglobin and other interfering sources for obtaining more accurate measurements. The laser radiation transmitted through the tissue is detected and signal processing based on differential absorption laser spectroscopy is done in such a way to overcome the primary performance limitations of the conventionally used pulse oximetry. The new laser pulse oximeter can detect weak signals and is not affected by other light sources such as surgical lamps, phototherapy units, etc. The detailed description and operating characteristics of this system are presented.

  1. Development of portable laser peening systems for nuclear power reactors

    International Nuclear Information System (INIS)

    Chida, Itaru; Uehara, Takuya; Yoda, Masaki; Miyasaka, Hiroyuki; Kato, Hiromi

    2009-01-01

    Stress corrosion cracking (SCC) is the major factor to reduce the reliability of aged reactor components. Toshiba has developed various laser-based maintenance and repair technologies and applied them to existing nuclear power plants. Laser-based technology is considered to be the best tool for remote processing in nuclear power plants, and particularly so for the maintenance and repair of reactor core components. Accessibility could be drastically improved by a simple handling system owing to the absence of reactive force against laser irradiation and the flexible optical fiber. For the preventive maintenance, laser peening technology was developed and applied to reactor components in operating BWRs and PWRs. Laser peening is a novel process to improve residual stress from tensile to compressive on material surface layer by irradiating focused high-power laser pulses in water without any surface preparations. Laser peening systems, which deliver laser pulses with mirrors or through an optical fiber, were developed and have been applied to preventive maintenance against SCC in nuclear power reactors since 1999. Each system was composed of laser oscillators, a beam delivery system, a laser irradiation head, remote handling equipment and a monitor/control system. Beam delivery with mirrors was accomplished through alignment/tracking functions with sufficient accuracy. Reliable fiber-delivery was attained by the development of a novel input coupling optics and an irradiation head with auto-focusing. Recently, we have developed portable laser peening (PLP) system which could employ both mirror- and fiber- delivery technologies. Size and weight of the PLP system for BWR bottom was almost 1/25 compared to the previous system. PLP system would be the applicable to both BWRs and PWRs as one of the maintenance technologies. (author)

  2. Mercury: The Los Alamos ICF KrF laser system

    International Nuclear Information System (INIS)

    Czuchlewski, S.J.; York, G.W.; Bigio, I.J.; Brucker, J.; Hanson, D.; Honig, E.M.; Kurnit, N.; Leland, W.; McCown, A.W.; McLeod, J.; Rose, E.; Thomas, S.; Thompson, D.

    1993-01-01

    The Mercury KrF laser facility at Los Alamos is being built with the benefit of lessons learned from the Aurora system. An increased understanding of KrF laser engineering, and the designed implementation of system flexibility, will permit Mercury to serve as a tested for a variety of advanced KrF technology concepts

  3. Solid-state disk amplifiers for fusion-laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Martin, W.E.; Trenholme, J.B.; Linford, G.J.; Yarema, S.M.; Hurley, C.A.

    1981-09-01

    We review the design, performance, and operation of large-aperture (10 to 46 cm) solid-state disk amplifiers for use in laser systems. We present design data, prototype tests, simulations, and projections for conventional cylindrical pump-geometry amplifiers and rectangular pump-geometry disk amplifiers. The design of amplifiers for the Nova laser system is discussed.

  4. Mechanical design for a large fusion laser system

    International Nuclear Information System (INIS)

    Hurley, C.A.

    1979-01-01

    The Nova Mechanical Systems Group at LLL is responsible for the design, fabrication, and installation of all laser chain components, for the stable support structure that holds them, and for the beam lines that transport the laser beam to the target system. This paper is an overview of the group's engineering effort, emphasizing new developments

  5. Pulse propagation properties in high-power CO2 laser system for laser fusion

    International Nuclear Information System (INIS)

    Daido, H.; Inoue, M.; Fujita, H.; Matoba, M.; Nakai, S.

    1981-01-01

    The simulation results of nonlinear propagation properties in the CO 2 laser system using a simulation model of the SF 6 saturable absorbers and the CO 2 laser amplifiers agree well with the experimental results. The technical problems of the simultaneous irradiation of the multi-beams to a target are also discussed. (author)

  6. Research on laser cladding control system based on fuzzy PID

    Science.gov (United States)

    Zhang, Chuanwei; Yu, Zhengyang

    2017-12-01

    Laser cladding technology has a high demand for control system, and the domestic laser cladding control system mostly uses the traditional PID control algorithm. Therefore, the laser cladding control system has a lot of room for improvement. This feature is suitable for laser cladding technology, Based on fuzzy PID three closed-loop control system, and compared with the conventional PID; At the same time, the laser cladding experiment and friction and wear experiment were carried out under the premise of ensuring the reasonable control system. Experiments show that compared with the conventional PID algorithm in fuzzy the PID algorithm under the surface of the cladding layer is more smooth, the surface roughness increases, and the wear resistance of the cladding layer is also enhanced.

  7. Percutaneous transluminal angioplasty of infrarenal arteries in intermittent claudication

    DEFF Research Database (Denmark)

    Henriksen, L O; Jørgensen, B; Holstein, P E

    1988-01-01

    Percutaneous transluminal angioplasty was performed on 55 iliac and 31 femoropopliteal arteries in 71 patients with intermittent claudication (23 women, 48 men). The two-year patency rate was 80% after iliac and 41% after femoropopliteal angioplasty. In 17 femoropopliteal cases with lesions greater...... than or equal to 5 cm the 2-year patency rate was only 32%, but the corresponding figure for shorter lesions was 53%. Complicating haematoma appeared in 10% of the cases and the arterial state deteriorated in one patient. There was no distal embolization. Percutaneous transluminal angioplasty...

  8. High-Voltage Power Supply System for Laser Isotope Separation

    Energy Technology Data Exchange (ETDEWEB)

    Ketaily, E.C.; Buckner, R.P.; Uhrik, R.L.

    1979-06-26

    This report presents several concepts for Laser High-Voltage Power Supply (HVPS) Systems for a Laser Isotope Separation facility. Selection of equipments and their arrangement into operational systems is based on proven designs and on application concepts now being developed. This report has identified a number of alternative system arrangements and has provided preliminary cost estimates for each. The report includes a recommendation for follow-on studies that will further define the optimum Laser HVPS Systems. Brief descriptions are given of Modulator/Regulator circuit trade-offs, system control interfaces, and their impact on costs.

  9. High-Voltage Power Supply System for Laser Isotope Separation

    International Nuclear Information System (INIS)

    Ketaily, E.C.; Buckner, R.P.; Uhrik, R.L.

    1979-01-01

    This report presents several concepts for Laser High-Voltage Power Supply (HVPS) Systems for a Laser Isotope Separation facility. Selection of equipments and their arrangement into operational systems is based on proven designs and on application concepts now being developed. This report has identified a number of alternative system arrangements and has provided preliminary cost estimates for each. The report includes a recommendation for follow-on studies that will further define the optimum Laser HVPS Systems. Brief descriptions are given of Modulator/Regulator circuit trade-offs, system control interfaces, and their impact on costs

  10. Lasers in tattoo and pigmentation control: role of the PicoSure® laser system

    Science.gov (United States)

    Torbeck, Richard; Bankowski, Richard; Henize, Sarah; Saedi, Nazanin

    2016-01-01

    Background and objectives The use of picosecond lasers to remove tattoos has greatly improved due to the long-standing outcomes of nanosecond lasers, both clinically and histologically. The first aesthetic picosecond laser available for this use was the PicoSure® laser system (755/532 nm). Now that a vast amount of research on its use has been conducted, we performed a comprehensive review of the literature to validate the continued application of the PicoSure® laser system for tattoo removal. Study design and methods A PubMed search was conducted using the term “picosecond” combined with “laser”, “dermatology”, and “laser tattoo removal”. Results A total of 13 articles were identified, and ten of these met the inclusion criteria for this review. The majority of studies showed that picosecond lasers are an effective and safe treatment mode for the removal of tattoo pigments. Several studies also indicated potential novel applications of picosecond lasers in the removal of various tattoo pigments (eg, black, red, and yellow). Adverse effects were generally mild, such as transient hypopigmentation or blister formation, and were rarely more serious, such as scarring and/or textural change. Conclusion Advancements in laser technologies and their application in cutaneous medicine have revolutionized the field of laser surgery. Computational modeling provides evidence that the optimal pulse durations for tattoo ink removal are in the picosecond domain. It is recommended that the PicoSure® laser system continue to be used for safe and effective tattoo removal, including for red and yellow pigments. PMID:27194919

  11. High Average Power, High Energy Short Pulse Fiber Laser System

    Energy Technology Data Exchange (ETDEWEB)

    Messerly, M J

    2007-11-13

    Recently continuous wave fiber laser systems with output powers in excess of 500W with good beam quality have been demonstrated [1]. High energy, ultrafast, chirped pulsed fiber laser systems have achieved record output energies of 1mJ [2]. However, these high-energy systems have not been scaled beyond a few watts of average output power. Fiber laser systems are attractive for many applications because they offer the promise of high efficiency, compact, robust systems that are turn key. Applications such as cutting, drilling and materials processing, front end systems for high energy pulsed lasers (such as petawatts) and laser based sources of high spatial coherence, high flux x-rays all require high energy short pulses and two of the three of these applications also require high average power. The challenge in creating a high energy chirped pulse fiber laser system is to find a way to scale the output energy while avoiding nonlinear effects and maintaining good beam quality in the amplifier fiber. To this end, our 3-year LDRD program sought to demonstrate a high energy, high average power fiber laser system. This work included exploring designs of large mode area optical fiber amplifiers for high energy systems as well as understanding the issues associated chirped pulse amplification in optical fiber amplifier systems.

  12. Investigations of a Dual Seeded 1178 nm Raman Laser System

    Science.gov (United States)

    2016-01-14

    was obtained by Raman amplification of a distributed feedback diode laser in a variably strained polarization- maintaining fiber with a record-high...Calia, D.B., “50W CW visible laser source at 589 nm obtained via frequency doubling of three coherently combined narrow-band Raman fiber amplifiers...AFRL-RD-PS- TP-2016-0009 AFRL-RD-PS- TP-2016-0009 INVESTIGATIONS OF A DUAL SEEDED 1178 NM RAMAN LASER SYSTEM Leanne Henry, et al. 14 January

  13. Popliteal artery thrombosis in a patient with Cogan syndrome: Treatment with thrombolysis and percutaneous transluminal angioplasty

    International Nuclear Information System (INIS)

    Bastug, Demir E.; Dominic, Anthony; Ortiz, Orlando; DiBartolomeo, Anthony G.; Kotzan, Jeffrey M.; Abraham, F. Matthew

    1997-01-01

    A 31-year-old woman with Cogan syndrome (a rare form of systemic vasculitis) was evaluated for a cold, painful left foot with diminished pulses. Arteriography demonstrated thrombosis of the left popliteal artery with evidence of vasculitis. Thrombolytic therapy was begun with initial success but eventual rethrombosis. After reinitiating thrombolytic therapy combined with intraarterial vasodilator therapy, successful angioplasty was performed with sustained results, at 6-month follow-up

  14. A control system for a free electron laser experiment

    International Nuclear Information System (INIS)

    Giove, D.

    1992-01-01

    The general layout of a control and data acquisition system for a Free Electron Laser experiment will be discussed. Some general considerations about the requirements and the architecture of the whole system will be developed. (author)

  15. High power radiation guiding systems for laser driven accelerators

    International Nuclear Information System (INIS)

    Cutolo, A.

    1985-01-01

    This paper reviews the main problems encountered in the design of an optical system for transmitting high fluence radiation in a laser driven accelerator. Particular attention is devoted to the analysis of mirror and waveguide systems. (orig.)

  16. Emergency coronary angioplasty with stenting using Cordis® diagnostic coronary catheters when there is difficulty in engaging guide catheters and bench evaluation of diagnostic and guide catheters.

    Science.gov (United States)

    Arokiaraj, Mark Christopher

    2018-02-01

    Difficulty in engaging with guide catheters is not uncommon in acute emergencies. We aimed to evaluate the use of Cordis ® INFINITI diagnostic catheters to perform angioplasty in patients in whom the coronaries cannot be engaged using standard guide catheters. In 34 cases of acute coronary syndrome, when difficulty in engagement with two standard guide catheters was encountered with reasonable manipulations, angioplasty was performed using diagnostic catheters. In total, 40 stents were placed by this technique. Pushability and trackability, distal tip flexion and three-point bending tests were performed to evaluate the performance of the guide and diagnostic catheters. Angioplasty was performed easily in a setting where it would have been very difficult to perform. Coronary dissection occurred in one patient, treated by a stent. The stent and dilatation balloons were easily passed through the diagnostic catheters. Pressure tracings were clearly preserved with certain stent delivery systems, and at angioplasty, although there was slightly reduced opacification of the respective artery, the coronary anatomy was sufficiently visualized to perform angioplasty. No periprocedural target lesion complications were seen in any cases. Pushability and trackability tests showed good force transmission along a tortuous path with diagnostic catheters, and balanced force-displacement curves from three-point bending tests and distal tip softness tests. Angioplasty with stenting can be performed safely through 6F Cordis ® infiniti diagnostic catheters when difficulty in engaging guide catheters is encountered. Copyright © 2018 Sociedade Portuguesa de Cardiologia. Publicado por Elsevier España, S.L.U. All rights reserved.

  17. Design of a laser scanner for a digital mammography system.

    Science.gov (United States)

    Rowlands, J A; Taylor, J E

    1996-05-01

    We have developed a digital readout system for radiographic images using a scanning laser beam. In this system, electrostatic charge images on amorphous selenium (alpha-Se) plates are read out using photo-induced discharge (PID). We discuss the design requirements of a laser scanner for the PID system and describe its construction from commercially available components. The principles demonstrated can be adapted to a variety of digital imaging systems.

  18. High average power solid state laser power conditioning system

    International Nuclear Information System (INIS)

    Steinkraus, R.F.

    1987-01-01

    The power conditioning system for the High Average Power Laser program at Lawrence Livermore National Laboratory (LLNL) is described. The system has been operational for two years. It is high voltage, high power, fault protected, and solid state. The power conditioning system drives flashlamps that pump solid state lasers. Flashlamps are driven by silicon control rectifier (SCR) switched, resonant charged, (LC) discharge pulse forming networks (PFNs). The system uses fiber optics for control and diagnostics. Energy and thermal diagnostics are monitored by computers

  19. Laser metrology in food-related systems

    Science.gov (United States)

    Mendoza-Sanchez, Patricia; Lopez, Daniel; Kongraksawech, Teepakorn; Vazquez, Pedro; Torres, J. Antonio; Ramirez, Jose A.; Huerta-Ruelas, Jorge

    2005-02-01

    An optical system was developed using a low-cost semiconductor laser and commercial optical and electronic components, to monitor food processes by measuring changes in optical rotation (OR) of chiral compounds. The OR signal as a function of processing time and sample temperature were collected and recorded using a computer data acquisition system. System has been tested during two different processes: sugar-protein interaction and, beer fermentation process. To study sugar-protein interaction, the following sugars were used: sorbitol, trehalose and sucrose, and in the place of Protein, Serum Albumin Bovine (BSA, A-7906 Sigma-Aldrich). In some food processes, different sugars are added to protect damage of proteins during their processing, storage and/or distribution. Different sugar/protein solutions were prepared and heated above critical temperature of protein denaturation. OR measurements were performed during heating process and effect of different sugars in protein denaturation was measured. Higher sensitivity of these measurements was found compared with Differential Scanning Calorimetry, which needs higher protein concentration to study these interactions. The brewing fermentation process was monitored in-situ using this OR system and validated by correlation with specific density measurements and gas chromatography. This instrument can be implemented to monitor fermentation on-line, thereby determining end of process and optimizing process conditions in an industrial setting. The high sensitivity of developed OR system has no mobile parts and is more flexible than commercial polarimeters providing the capability of implementation in harsh environments, signifying the potential of this method as an in-line technique for quality control in food processing and for experimentation with optically active solutions.

  20. Renal artery stent angioplasty for renovascular hypertension

    International Nuclear Information System (INIS)

    Li Gang; Li Haiqing; Wang Lin

    2005-01-01

    Objective: To evaluate the therapeutic results of expandable stent for treatment of atherosclerotic renovascular obstructive disease. Methods: 15 patients (10 men and 5 women, 41-75 years old; mean age, 52 years) with renal arterial hypertension underwent renal stent angioplasty including renal arterial stenosis 89%(n=13) and fully obstruction without function in 2, of which 2 patients had bilateral involvement. The stenotic range of all arterial segments showed 60% to 90% width of the normal arterial diameter. 16 stents were implanted under the guidance of fluoroscopy. The most of stents implanted were Palmaz (n=12, 75%) with regular clinical and angiographic follow up. Results: Technical success (residual stenosis <30%) was achieved in all patients without serious complication. During the follow-up (6-15 months; mean, 8 ± 4 months), hypertension was improved in 9 patients and cured in 4 patients with a total benefit of 86% and no efficacy in 2(13%). The average systolic blood pressure decreased from 27.12 ± 3.09 kPa to 18.62 ± 3.12 kPa and the average diastolic blood pressure decreased from 17.73 ± 1.92 kPa to 11.12 ± 2.43 kPa after stent treatment (P<0.05). Serum creatinine remained stable in 60% (n=9) patients with improvement in 33% (n=5) and worsened in 6% (n=1) patients. Follow-up angiography was performed in all patients with 1 case of a restenosis. 6 months after expanding through stent by using balloon, the two follow up angiographies showed a stable restenosis about 20%. Conclusions: Percutaneous transluminal stent placement is highly beneficial for patients who had renal arterial obstructive disease. The success of stent angioplasty of complete obstructive renal arteries reveals wide prospects for interventional method. (authors)

  1. Laser and plasma diagnostics for the OMEGA Upgrade Laser System (invited) (abstract)

    International Nuclear Information System (INIS)

    Letzring, S.A.

    1995-01-01

    The upgraded OMEGA laser system will be capable of delivering up to 30 kJ of 351-nm laser light with various temporal pulse shapes onto a variety of targets for both ICF and basic plasma physics experiments. ICF experiments will cover a wide parameter space up to near-ignition conditions, and basic interaction and plasma physics experiments will cover previously unattainable parameter spaces. The laser system is the tool with which the experiments are performed; the diagnostics, both of the laser system and the interaction between the laser and the target, form the heart of the experiment. A new suite of diagnostics is now being designed and constructed. Most of these are based on diagnostics previously fielded on the OMEGA laser system very successfully over the last ten years, but there are some new diagnostics, both for the laser and the interaction experiments, which have had to be invented. Laser system diagnostics include high-energy, full-beam calorimetry for all of the 60 beams of the upgrade; a novel, multispectral energy-measuring system for assessing the tuning of the frequency-multiplying crystals; a beam-balance diagnostic that forms the heart of the energy-balance system; and a peak power diagnostic that forms the heart of the power-balance system. Target diagnostics will include the usual time-integrated x-ray imaging systems, both pinhole cameras and x-ray microscopes; x-ray spectrometers, both imaging and spatially integrating; plamsa calorimeters, including x-ray calorimetry; and time-resolved x-ray diagnostics, both nonimaging and imaging in one and two dimensions. Neutron diagnostics will include several measurements of total yield, secondary, and possibly tertiary yield and neutron spectroscopy with several time-of-flight spectrometers. Other measurements will include ''knock-on'' particle measurements and neutron activation of shell materials as a diagnostic of compressed fuel and shell density

  2. Nuclear Techniques for Coronary Heart Disease Therapy after Percutaneous Transluminal Coronary Angioplasty

    International Nuclear Information System (INIS)

    Nurlaila-Z

    2005-01-01

    Nuclear techniques studies of the heart represent one of the fastest growing areas of research. Several years ago, nuclear medicine cardiac studies were limited for the evaluation and diagnosis of myocardial infarction. Development in radiopharmaceutical-chemistry and instrumentation have made possible advances in nuclear medicine for restenosis cardiovascular therapy after percutaneous transluminal coronary angioplasty.The radionuclide as radiation source can be delivered to the target basically by two techniques, those are catheter-based systems and radioactive stents. For this purpose,it can be use the γ and β emitter radionuclides, in which the β emitter radionuclides is an ideal radionuclide for endovascular therapy. Restenosis after percutaneous transluminal coronary angioplasty can be prevented by using the radioactive stent. This review discusses several techniques which could be used for restenosis cardiovascular therapy. Furthermore, several types of radiopharmaceutical and kinds of radionuclides as well as doses of the compounds for this purpose are also reviewed. (author)

  3. Successful Venous Angioplasty of Superior Vena Cava Syndrome after Heart Transplantation

    Directory of Open Access Journals (Sweden)

    Thomas Strecker

    2014-01-01

    Full Text Available Introduction. For patients with terminal heart failure, heart transplantation (HTX has become an established therapy. Before transplantation there are many repeated measurements with a pulmonary artery catheter (PAC via the superior vena cava (SVC necessary. After transplantation, endomyocardial biopsy (EMB is recommended for routine surveillance of heart transplant rejection again through the SVC. Case Presentation. In this report, we present a HTX patient who developed a SVC syndrome as a possible complication of all these procedures via the SVC. This 35-year-old Caucasian male could be successfully treated by balloon dilatation/angioplasty. Conclusion. The SVC syndrome can lead to pressure increase in the venous system such as edema in the head and the upper part of the body and further serious complications like cerebral bleeding and ischemia, or respiratory problems. Balloon angioplasty and stent implantation are valid methods to treat stenoses of the SVC successfully.

  4. Laser cutting of irregular shape object based on stereo vision laser galvanometric scanning system

    Science.gov (United States)

    Qi, Li; Zhang, Yixin; Wang, Shun; Tang, Zhiqiang; Yang, Huan; Zhang, Xuping

    2015-05-01

    Irregular shape objects with different 3-dimensional (3D) appearances are difficult to be shaped into customized uniform pattern by current laser machining approaches. A laser galvanometric scanning system (LGS) could be a potential candidate since it can easily achieve path-adjustable laser shaping. However, without knowing the actual 3D topography of the object, the processing result may still suffer from 3D shape distortion. It is desirable to have a versatile auxiliary tool that is capable of generating 3D-adjusted laser processing path by measuring the 3D geometry of those irregular shape objects. This paper proposed the stereo vision laser galvanometric scanning system (SLGS), which takes the advantages of both the stereo vision solution and conventional LGS system. The 3D geometry of the object obtained by the stereo cameras is used to guide the scanning galvanometers for 3D-shape-adjusted laser processing. In order to achieve precise visual-servoed laser fabrication, these two independent components are integrated through a system calibration method using plastic thin film target. The flexibility of SLGS has been experimentally demonstrated by cutting duck feathers for badminton shuttle manufacture.

  5. Construction of a femtosecond laser microsurgery system.

    Science.gov (United States)

    Steinmeyer, Joseph D; Gilleland, Cody L; Pardo-Martin, Carlos; Angel, Matthew; Rohde, Christopher B; Scott, Mark A; Yanik, Mehmet Fatih

    2010-03-01

    Femtosecond laser microsurgery is a powerful method for studying cellular function, neural circuits, neuronal injury and neuronal regeneration because of its capability to selectively ablate sub-micron targets in vitro and in vivo with minimal damage to the surrounding tissue. Here, we present a step-by-step protocol for constructing a femtosecond laser microsurgery setup for use with a widely available compound fluorescence microscope. The protocol begins with the assembly and alignment of beam-conditioning optics at the output of a femtosecond laser. Then a dichroic mount is assembled and installed to direct the laser beam into the objective lens of a standard inverted microscope. Finally, the laser is focused on the image plane of the microscope to allow simultaneous surgery and fluorescence imaging. We illustrate the use of this setup by presenting axotomy in Caenorhabditis elegans as an example. This protocol can be completed in 2 d.

  6. A digital intensity stabilization system for HeNe laser

    Science.gov (United States)

    Wei, Zhimeng; Lu, Guangfeng; Yang, Kaiyong; Long, Xingwu; Huang, Yun

    2012-02-01

    A digital intensity stabilization system for HeNe laser is developed. Based on a switching power IC to design laser power supply and a general purpose microcontroller to realize digital PID control, the system constructs a closed loop to stabilize the laser intensity by regulating its discharge current. The laser tube is made of glass ceramics and its integrated structure is steady enough to eliminate intensity fluctuations at high frequency and attenuates all intensity fluctuations, and this makes it easy to tune the control loop. The control loop between discharge current and photodiode voltage eliminates the long-term drifts. The intensity stability of the HeNe laser with this system is 0.014% over 12 h.

  7. Investigation of dye laser excitation of atomic systems

    International Nuclear Information System (INIS)

    Abate, J.A.

    1977-01-01

    A stabilized cw dye laser system and an optical pumping scheme for a sodium atomic beam were developed, and the improvements over previously existing systems are discussed. A method to stabilize both the output intensity and the frequency of the cw dye laser for periods of several hours is described. The fluctuation properties of this laser are investigated by photon counting and two-time correlation measurements. The results show significant departures from the usual single-mode laser theory in the region of threshold and below. The implications of the deviation from accepted theory are discussed. The atomic beam system that was constructed and tested is described. A method of preparing atomic sodium so that it behaves as a simple two-level atom is outlined, and the results of some experiments to study the resonant interaction between the atoms and the dye laser beam are presented

  8. Blue laser diode (450 nm) systems for welding copper

    Science.gov (United States)

    Silva Sa, M.; Finuf, M.; Fritz, R.; Tucker, J.; Pelaprat, J.-M.; Zediker, M. S.

    2018-02-01

    This paper will discuss the development of high power blue laser systems for industrial applications. The key development enabling high power blue laser systems is the emergence of high power, high brightness laser diodes at 450 nm. These devices have a high individual brightness rivaling their IR counterparts and they have the potential to exceed their performance and price barriers. They also have a very high To resulting in a 0.04 nm/°C wavelength shift. They have a very stable lateral far-field profile which can be combined with other diodes to achieve a superior brightness. This paper will report on the characteristics of the blue laser diodes, their integration into a modular laser system suitable for scaling the output power to the 1 kW level and beyond. Test results will be presented for welding of copper with power levels ranging from 150 Watts to 600 Watts

  9. OCT evaluation of directional atherectomy compared to balloon angioplasty.

    Science.gov (United States)

    Marmagkiolis, Konstantinos; Lendel, Vasili; Cilingiroglu, Mehmet

    2015-09-01

    Directional atherectomy (DA) is one of the most commonly used modalities for the treatment of obstructive femoropopliteal peripheral arterial disease (PAD), especially in patients with large and calcified atherosclerotic plaques. The effect of directional atherectomy to the vascular wall compared to balloon angioplasty by optical coherence tomography (OCT) has not been previously described. We present the first case of OCT after directional atherectomy with SilverHawk followed by angiosculpt balloon angioplasty. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. False coronary dissection with the new Monorail angioplasty balloon catheter.

    Science.gov (United States)

    Esplugas, E; Cequier, A R; Sabaté, X; Jara, F

    1990-01-01

    During percutaneous transluminal coronary angioplasty, the appearance of persistent staining in the vessel by contrast media suggests coronary dissection. We report seven patients in whom a false image of severe coronary dissection was observed during angioplasty performed with the new Monorail balloon catheter. This image emerges at the moment of balloon inflation, is distally located to the balloon, and disappears with balloon catheter deflation. No complications were associated with the appearance of this image.

  11. Transluminal angioplasty of a stenotic surgical splenorenal shunt

    International Nuclear Information System (INIS)

    Beers, B. van; Roche, A.; Cauquil, P.

    1988-01-01

    A stenosis of a side-to-side splenorenal shunt was treated by percutaneous angioplasty two years after the performance of the shunt. After dilatation, there was a fall of the splenorenal pressure gradient from 28 to 17 cm H 2 O and good transanastomotic flow was re-estabilshed. As in other arterial and venous territories, angioplasty may be an interesting alternative to surgery. (orig.)

  12. lambda-3, Sandia's 100-J HF laser system

    International Nuclear Information System (INIS)

    Klein, R.A.

    1979-09-01

    Sandia's lambda-geometry intermediate electron-beam-initiated HF amplifier is described in sufficient detail such that a similar system could be designed, constructed and characterized. Items included are the design of the laser cell, magnetic field design and measurements, electron-beam calorimetry, and typical laser results

  13. DFB fiber laser as source for optical communication systems

    DEFF Research Database (Denmark)

    Varming, Poul; Hübner, Jörg; Kristensen, Martin

    1997-01-01

    The results demonstrate that DFB fiber lasers are an attractive alternative as sources in telecommunication systems. The lasers show excellent long-term stability with very high signal to noise ratio and a reasonable output power, combined with exceptional temperature stability and inherent fiber...

  14. Mechanical technology unique to laser fusion experimental systems

    International Nuclear Information System (INIS)

    Hurley, C.A.

    1980-01-01

    Hardware design for laser fusion experimental machines has led to a combination of engineering technologies that are critical to the successful operation of these machines. These large opto-mechanical systems are dependent on extreme cleanliness, accommodation to efficient maintenance, and high stability. These three technologies are the primary mechanical engineering criteria for laser fusion devices

  15. Optical System Design and Integration of the Mercury Laser Altimeter

    Science.gov (United States)

    Ramos-Izquierdo, Luis; Scott, V. Stanley, III; Schmidt, Stephen; Britt, Jamie; Mamakos, William; Trunzo, Raymond; Cavanaugh, John; Miller, Roger

    2005-01-01

    The Mercury Laser Altimeter (MLA). developed for the 2004 MESSENGER mission to Mercury, is designed to measure the planet's topography via laser ranging. A description of the MLA optical system and its measured optical performance during instrument-level and spacecraft-level integration and testing are presented.

  16. Non-contact finger vein acquisition system using NIR laser

    Science.gov (United States)

    Kim, Jiman; Kong, Hyoun-Joong; Park, Sangyun; Noh, SeungWoo; Lee, Seung-Rae; Kim, Taejeong; Kim, Hee Chan

    2009-02-01

    Authentication using finger vein pattern has substantial advantage than other biometrics. Because human vein patterns are hidden inside the skin and tissue, it is hard to forge vein structure. But conventional system using NIR LED array has two drawbacks. First, direct contact with LED array raise sanitary problem. Second, because of discreteness of LEDs, non-uniform illumination exists. We propose non-contact finger vein acquisition system using NIR laser and Laser line generator lens. Laser line generator lens makes evenly distributed line laser from focused laser light. Line laser is aimed on the finger longitudinally. NIR camera was used for image acquisition. 200 index finger vein images from 20 candidates are collected. Same finger vein pattern extraction algorithm was used to evaluate two sets of images. Acquired images from proposed non-contact system do not show any non-uniform illumination in contrary with conventional system. Also results of matching are comparable to conventional system. We developed Non-contact finger vein acquisition system. It can prevent potential cross contamination of skin diseases. Also the system can produce uniformly illuminated images unlike conventional system. With the benefit of non-contact, proposed system shows almost equivalent performance compared with conventional system.

  17. Railgun system using a laser-induced plasma armature

    International Nuclear Information System (INIS)

    Onozuka, M.; Oda, Y.; Azuma, K.

    1996-01-01

    Development of an electromagnetic railgun system that utilizes a laser-induced plasma armature formation has been conducted to investigate the application of the railgun system for high-speed pellet injection into fusion plasmas. Using the laser-induced plasma formation technique, the required breakdown voltage was reduced by one-tenth compared with that for the spark-discharged plasma. The railgun system successfully accelerated the laser-induced plasma armature by an electromagnetic force that accelerated the pellet. The highest velocity of the solid hydrogen pellets, obtained so far, was 2.6 km/sec using a 2m-long railgun. copyright 1996 American Institute of Physics

  18. Railgun system using a laser-induced plasma armature

    Science.gov (United States)

    Onozuka, Masanori; Oda, Yasushi; Azuma, Kingo

    1996-05-01

    Development of an electromagnetic railgun system that utilizes a laser-induced plasma armature formation has been conducted to investigate the application of the railgun system for high-speed pellet injection into fusion plasmas. Using the laser-induced plasma formation technique, the required breakdown voltage was reduced by one-tenth compared with that for the spark-discharged plasma. The railgun system successfully accelerated the laser-induced plasma armature by an electromagnetic force that accelerated the pellet. The highest velocity of the solid hydrogen pellets, obtained so far, was 2.6 km/sec using a 2m-long railgun.

  19. Railgun system using a laser-induced plasma armature

    Energy Technology Data Exchange (ETDEWEB)

    Onozuka, M.; Oda, Y.; Azuma, K. [Mitsubishi Heavy Industries, Ltd., 3-3-1, Minatomirai, Nishi-ku, Yokohama 220-84 (Japan)

    1996-05-01

    Development of an electromagnetic railgun system that utilizes a laser-induced plasma armature formation has been conducted to investigate the application of the railgun system for high-speed pellet injection into fusion plasmas. Using the laser-induced plasma formation technique, the required breakdown voltage was reduced by one-tenth compared with that for the spark-discharged plasma. The railgun system successfully accelerated the laser-induced plasma armature by an electromagnetic force that accelerated the pellet. The highest velocity of the solid hydrogen pellets, obtained so far, was 2.6 km/sec using a 2m-long railgun. {copyright} {ital 1996 American Institute of Physics.}

  20. A laser calibration system for the STAR TPC

    CERN Document Server

    Lebedev, A

    2002-01-01

    A Time Projection Chamber (TPC) is the primary tracking detector for the STAR experiment at RHIC. A laser calibration system was built to calibrate and monitor the TPC tracking performance. The laser system uses a novel design which produces approx 500 thin, ionizing beams distributed throughout the tracking volume. This new approach is significantly simpler than the traditional ones, and provides complete TPC coverage at a reduced cost. The laser system was used during the RHIC 2000 summer run to measure drift velocities with about 0.02% accuracy and to monitor the TPC performance. Calibration runs were made with and without a magnetic field to check B field map corrections.

  1. Thin-Film Polarizers for the OMEGA EP Laser System

    International Nuclear Information System (INIS)

    Oliver, J.B.; Rigatti, A.L.; Howe, J.D.; Keck, J.; Szczepanski, J.; Schmid, A.W.; Papernov, S.; Kozlov, A.; Kosc, T.Z.

    2006-01-01

    Thin-film polarizers are essential components of large laser systems such as OMEGA EP and the NIF because of the need to switch the beam out of the primary laser cavity (in conjunction with a plasma-electrode Pockels cell) as well as providing a well-defined linear polarization for frequency conversion and protecting the system from back-reflected light. The design and fabrication of polarizers for pulse-compressed laser systems is especially challenging because of the spectral bandwidth necessary for chirped-pulse amplification

  2. Coherent Laser Radar Metrology System for Large Scale Optical Systems, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A new type of laser radar metrology inspection system is proposed that incorporates a novel, dual laser coherent detection scheme capable of eliminating both...

  3. Optical system for laser triggering of PBFA II

    International Nuclear Information System (INIS)

    Hamil, R.A.; Seamons, L.O.; Schanwald, L.P.; Gerber, R.A.

    1985-01-01

    The PBFA II laser triggering optical system consists of nearly 300 optical components. These optics must be sufficiently precise to preserve the laser beam quality, as well as to equally distribute the energy of the UV laser beam to the 36, 5.5 MV gas-filled switches at precisely the same instant. Both index variation and cleanliness of the air long the laser path must be controlled. The manual alignment system is capable of alignment to better than the acceptable error of 200 microradians (laser to switches). A technique has been devised to ease the alignment procedure by using a special high gain video camera and a tool alignment telescope to view retroreflective tape targets having optical brightness gains over white surfaces of 10/sup 3/. The camera is a charge-coupled detector intensified by a double microchannel plate having an optical gain of between 10/sup 4/ and 10/sup 5/

  4. Performance of the Aurora KrF ICF laser system

    International Nuclear Information System (INIS)

    Jones, J.E.; Czuchlewski, S.J.; Turner, T.P.; Watt, R.G.; Thomas, S.J.; Netz, D.A.; Tallman, C.R.; Mack, J.M.; Figueira, J.F.

    1990-01-01

    Because short wavelength lasers are attractive for inertial confinement fusion (ICF), the Department of Energy is sponsoring work at Los Alamos National Laboratory in krypton-fluoride (KrF) laser technology. Aurora is a short-pulse, high-power, KrF laser system. It serves as an end-to-end technology demonstration prototype for large-scale ultraviolet laser systems for short wavelength ICF research. The system employs optical angular multiplexing and serial amplification by electron-beam-driven KrF laser amplifiers. The 1 to 5 ns pulse of the Aurora front end is split into 96 beams which are angularly and temporally multiplexed to produce a 480 ns pulse train for amplification by four KrF laser amplifiers. In the present system configuration half (48) of the amplified pulses are demultiplexed using different optical path lengths and delivered simultaneously to target. This paper discusses how the Aurora laser system has entered the initial operational phase by delivering pulse energies of greater than one kilojoule to target

  5. Automated Laser Seeker Performance Evaluation System (ALSPES)

    Data.gov (United States)

    Federal Laboratory Consortium — This facility provides complete open-loop test capability for semi-active laser (SAL) seekers/sensors operating at 1.064 microns. ALSPES provides characterizations...

  6. Laser-GMA Hybrid Pipe Welding System

    National Research Council Canada - National Science Library

    Reutzel, Edward W; Kern, Ludwig; Sullivan, Michael J; Tressler, Jay F; Avalos, Juan

    2007-01-01

    The combination of laser welding with conventional gas metal arc welding technology offers substantial increases in production rate of joining pipe through single-pass joining compared to multi-pass...

  7. Fibrin Sheath Angioplasty: A Technique to Prevent Superior Vena Cava Stenosis Secondary to Dialysis Catheters

    Science.gov (United States)

    Hacker, Robert I.; Garcia, Lorena De Marco; Chawla, Ankur; Panetta, Thomas F.

    2012-01-01

    Fibrin sheaths are a heterogeneous matrix of cells and debris that form around catheters and are a known cause of central venous stenosis and catheter failure. A total of 50 cases of central venous catheter fibrin sheath angioplasty (FSA) after catheter removal or exchange are presented. A retrospective review of an outpatient office database identified 70 eligible patients over a 19-month period. After informed consent was obtained, the dialysis catheter exiting the skin was clamped, amputated, and a wire was inserted. The catheter was then removed and a 9-French sheath was inserted into the superior vena cava, a venogram was performed. If a fibrin sheath was present, angioplasty was performed using an 8 × 4 or 10 × 4 balloon along the entire length of the fibrin sheath. A completion venogram was performed to document obliteration of the sheath. During the study, 50 patients were diagnosed with a fibrin sheath, and 43 had no pre-existing central venous stenosis. After FSA, 39 of the 43 patient's (91%) central systems remained patent without the need for subsequent interventions; 3 patients (7%) developed subclavian stenoses requiring repeat angioplasty and stenting; 1 patent (2.3%) developed an occlusion requiring a reintervention. Seven patients with prior central stenosis required multiple angioplasties; five required stenting of their central lesions. Every patient had follow-up fistulograms to document long-term patency. We propose that FSA is a prudent and safe procedure that may help reduce the risk of central venous stenosis from fibrin sheaths due to central venous catheters. PMID:23997555

  8. Combined laser ultrasonics, laser heating, and Raman scattering in diamond anvil cell system

    Science.gov (United States)

    Zinin, Pavel V.; Prakapenka, Vitali B.; Burgess, Katherine; Odake, Shoko; Chigarev, Nikolay; Sharma, Shiv K.

    2016-12-01

    We developed a multi-functional in situ measurement system under high pressure equipped with a laser ultrasonics (LU) system, Raman device, and laser heating system (LU-LH) in a diamond anvil cell (DAC). The system consists of four components: (1) a LU-DAC system (probe and pump lasers, photodetector, and oscilloscope) and DAC; (2) a fiber laser, which is designed to allow precise control of the total power in the range from 2 to 100 W by changing the diode current, for heating samples; (3) a spectrometer for measuring the temperature of the sample (using black body radiation), fluorescence spectrum (spectrum of the ruby for pressure measurement), and Raman scattering measurements inside a DAC under high pressure and high temperature (HPHT) conditions; and (4) an optical system to focus laser beams on the sample and image it in the DAC. The system is unique and allows us to do the following: (a) measure the shear and longitudinal velocities of non-transparent materials under HPHT; (b) measure temperature in a DAC under HPHT conditions using Planck's law; (c) measure pressure in a DAC using a Raman signal; and (d) measure acoustical properties of small flat specimens removed from the DAC after HPHT treatment. In this report, we demonstrate that the LU-LH-DAC system allows measurements of velocities of the skimming waves in iron at 2580 K and 22 GPa.

  9. On-Chip Laser-Power Delivery System for Dielectric Laser Accelerators

    Science.gov (United States)

    Hughes, Tyler W.; Tan, Si; Zhao, Zhexin; Sapra, Neil V.; Leedle, Kenneth J.; Deng, Huiyang; Miao, Yu; Black, Dylan S.; Solgaard, Olav; Harris, James S.; Vuckovic, Jelena; Byer, Robert L.; Fan, Shanhui; England, R. Joel; Lee, Yun Jo; Qi, Minghao

    2018-05-01

    We propose an on-chip optical-power delivery system for dielectric laser accelerators based on a fractal "tree-network" dielectric waveguide geometry. This system replaces experimentally demanding free-space manipulations of the driving laser beam with chip-integrated techniques based on precise nanofabrication, enabling access to orders-of-magnitude increases in the interaction length and total energy gain for these miniature accelerators. Based on computational modeling, in the relativistic regime, our laser delivery system is estimated to provide 21 keV of energy gain over an acceleration length of 192 μ m with a single laser input, corresponding to a 108-MV/m acceleration gradient. The system may achieve 1 MeV of energy gain over a distance of less than 1 cm by sequentially illuminating 49 identical structures. These findings are verified by detailed numerical simulation and modeling of the subcomponents, and we provide a discussion of the main constraints, challenges, and relevant parameters with regard to on-chip laser coupling for dielectric laser accelerators.

  10. Excimer laser beam delivery systems for medical applications

    Science.gov (United States)

    Kubo, Uichi; Hashishin, Yuichi; Okada, Kazuyuki; Tanaka, Hiroyuki

    1993-05-01

    We have been doing the basic experiments of UV laser beams and biotissue interaction with both KrF and XeCl lasers. However, the conventional optical fiber can not be available for power UV beams. So we have been investigating about UV power beam delivery systems. These experiments carry on with the same elements doped quartz fibers and the hollow tube. The doped elements are OH ion, chlorine and fluorine. In our latest work, we have tried ArF excimer laser and biotissue interactions, and the beam delivery experiments. From our experimental results, we found that the ArF laser beam has high incision ability for hard biotissue. For example, in the case of the cow's bone incision, the incision depth by ArF laser was ca.15 times of KrF laser. Therefore, ArF laser would be expected to harden biotissue therapy as non-thermal method. However, its beam delivery is difficult to work in this time. We will develop ArF laser beam delivery systems.

  11. Laser display system for multi-depth screen projection scenarios.

    Science.gov (United States)

    La Torre, J Pablo; Mayes, Nathan; Riza, Nabeel A

    2017-11-10

    Proposed is a laser projection display system that uses an electronically controlled variable focus lens (ECVFL) to achieve sharp and in-focus image projection over multi-distance three-dimensional (3D) conformal screens. The system also functions as an embedded distance sensor that enables 3D mapping of the multi-level screen platform before the desired laser scanned beam focused/defocused projected spot sizes are matched to the different localized screen distances on the 3D screen. Compared to conventional laser scanning and spatial light modulator (SLM) based projection systems, the proposed design offers in-focus non-distorted projection over a multi-distance screen zone with varying depths. An experimental projection system for a screen depth variation of 65 cm is demonstrated using a 633 nm laser beam, 3 KHz scan speed galvo-scanning mirrors, and a liquid-based ECVFL. As a basic demonstration, an in-house developed MATLAB based graphic user interface is deployed to work along with the laser projection display, enabling user inputs like text strings or predefined image projection. The user can specify projection screen distance, scanned laser linewidth, projected text font size, projected image dimensions, and laser scanning rate. Projected images are shown highlighting the 3D control capabilities of the display, including the production of a non-distorted image onto two-depths versus a distorted image via dominant prior-art projection methods.

  12. Optical response in a laser-driven quantum pseudodot system

    Energy Technology Data Exchange (ETDEWEB)

    Kilic, D. Gul [Physics Department, Graduate School of Natural and Applied Sciences, Dokuz Eylül University, 35390 Izmir (Turkey); Sakiroglu, S., E-mail: serpil.sakiroglu@deu.edu.tr [Physics Department, Faculty of Science, Dokuz Eylül University, 35390 Izmir (Turkey); Ungan, F.; Yesilgul, U. [Department of Optical Engineering, Faculty of Technology, Cumhuriyet University, 58140 Sivas (Turkey); Kasapoglu, E. [Physics Department, Faculty of Science, Cumhuriyet University, 58140 Sivas (Turkey); Sari, H. [Department of Primary Education, Faculty of Education, Cumhuriyet University, 58140 Sivas (Turkey); Sokmen, I. [Physics Department, Faculty of Science, Dokuz Eylül University, 35390 Izmir (Turkey)

    2017-03-15

    We investigate theoretically the intense laser-induced optical absorption coefficients and refractive index changes in a two-dimensional quantum pseudodot system under an uniform magnetic field. The effects of non-resonant, monochromatic intense laser field upon the system are treated within the framework of high-frequency Floquet approach in which the system is supposed to be governed by a laser-dressed potential. Linear and nonlinear absorption coefficients and relative changes in the refractive index are obtained by means of the compact-density matrix approach and iterative method. The results of numerical calculations for a typical GaAs quantum dot reveal that the optical response depends strongly on the magnitude of external magnetic field and characteristic parameters of the confinement potential. Moreover, we have demonstrated that the intense laser field modifies the confinement and thereby causes remarkable changes in the linear and nonlinear optical properties of the system.

  13. Optical response in a laser-driven quantum pseudodot system

    International Nuclear Information System (INIS)

    Kilic, D. Gul; Sakiroglu, S.; Ungan, F.; Yesilgul, U.; Kasapoglu, E.; Sari, H.; Sokmen, I.

    2017-01-01

    We investigate theoretically the intense laser-induced optical absorption coefficients and refractive index changes in a two-dimensional quantum pseudodot system under an uniform magnetic field. The effects of non-resonant, monochromatic intense laser field upon the system are treated within the framework of high-frequency Floquet approach in which the system is supposed to be governed by a laser-dressed potential. Linear and nonlinear absorption coefficients and relative changes in the refractive index are obtained by means of the compact-density matrix approach and iterative method. The results of numerical calculations for a typical GaAs quantum dot reveal that the optical response depends strongly on the magnitude of external magnetic field and characteristic parameters of the confinement potential. Moreover, we have demonstrated that the intense laser field modifies the confinement and thereby causes remarkable changes in the linear and nonlinear optical properties of the system.

  14. Micro Sampling System for Highly Radioactive Specimen by Laser Ablation

    Energy Technology Data Exchange (ETDEWEB)

    Han, Sun Ho; Ha, Yeong Keong; Han, Ki Chul; Park, Yang Soon; Jee, Kwang Yong; Kim, Won Ho [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2005-03-15

    Shielded laser ablation system composed of laser system, image analyser, XYZ translator with motion controller, ablation chamber, manipulator and various optics was designed. Nd:YAG laser which can be tunable from 1064 nm to 266 nm was selected as light source. CCD camera(< x 200) was chosen to analyze a crater less than 50 un in diameter. XYZ translator was composed of three linear stage which can travel 50 w with a minimum movement of 1 {mu}m and motion controller. Before the performance test, each part of system was optically aligned. To perform the ablation test, the specimen was ablated by 50 {mu}m interval and observed by image analyser The shape of crater was almost round, indicating laser beam has homogeneous energy distribution. The resolution and magnification of image system were compatible with the design.

  15. Optical design of high power excimer laser system

    International Nuclear Information System (INIS)

    Zhang Yongsheng; Zhao Jun; Ma Lianying; Yi Aiping; Liu Jingru

    2011-01-01

    Image relay and angular multiplexing,which should be considered together in the design of high power excimer laser system, is reviewed. It's important to select proper illumination setup and laser beam shaping techniques. Given the complex and special angular multiplexing scheme in high power excimer laser systems, some detailed conceptual layout schemes are given in the paper. After a brief description of lens array and reflective telescope objective, which combine the incoming beams to a common focus, a new schematic layout which uses the final targeting optics and one optical delay line array, to realize multiplexing and de-multiplexing simultaneously is first proposed in the paper. (authors)

  16. Reporting standards for angioplasty and stent-assisted angioplasty for intracranial atherosclerosis.

    Science.gov (United States)

    Schumacher, H Christian; Meyers, Philip M; Higashida, Randall T; Derdeyn, Colin P; Lavine, Sean D; Nesbit, Gary M; Sacks, David; Rasmussen, Peter; Wechsler, Lawrence R

    2010-12-01

    Intracranial cerebral atherosclerosis causes ischemic stroke in a significant number of patients. Technological advances over the past 10 years have enabled endovascular treatment of intracranial atherosclerotic stenosis. The number of patients treated with angioplasty or stent-assisted angioplasty for this condition is increasing. Given the lack of universally accepted definitions, the goal of this document is to provide consensus recommendations for reporting standards, terminology, and written definitions when reporting clinical and radiological evaluation, technique, and outcome of endovascular treatment using angioplasty or stent-assisted angioplasty for stenotic and occlusive intracranial atherosclerosis. This article was written under the auspices of Joint Writing Group of the Technology Assessment Committee, Society of Neurolnterventional Surgery, Society of Interventional Radiology; Joint Section on Cerebro-vascular Neurosurgery of the American Association of Neurological Surgeons and Congress of Neurological Surgeons; and the Section of Stroke and Interventional Neurology of the American Academy of Neurology. A computerized search of the National Library of Medicine database of literature (PubMed) from January 1997 to December 2007 was conducted with the goal to identify published endovascular cerebrovascular interventional data in stenotic intracranial atherosclerosis that could be used as benchmarks for quality assessment. We sought to identify those risk adjustment variables that affect the likelihood of success and complications. This document offers the rationale for different clinical and technical considerations that may be important during the design of clinical trials for endovascular treatment of intracranial stenotic and occlusive atherosclerosis. Included in this guidance document are suggestions for uniform reporting standards for such trials. These definitions and standards are primarily intended for research purposes; however, they should

  17. Laser Transmitters for the optical link systems used in CMS

    CERN Multimedia

    Maximilien Brice

    2005-01-01

    In the CMS experiment of the now new flagship LHC optical links will be used for the tracker readout system. One part of this components will be semiconductor laser (~50.000 !!!), named correctly: 1310 nm InGaAsP (DCPBH-MQW) edge-emitting laser. They are foreseen as transmitter in the Tx Hybrid part of the optical link system.

  18. Quantum cascade lasers, systems, and applications in Europe

    Science.gov (United States)

    Lambrecht, Armin

    2005-03-01

    Since the invention of the Quantum Cascade Laser (QCL) a decade ago an impressive progress has been achieved from first low temperature pulsed laser emission to continuous wave operation at room temperature. Distributed feedback (DFB) lasers working in pulsed mode at ambient temperatures and covering a broad spectral range in the mid infrared (MIR) are commercially available now. For many industrial applications e.g. automotive exhaust control and process monitoring, laser spectroscopy is an established technique, generally using near infrared (NIR) diode lasers. However, the mid infrared (MIR) spectral region is of special interest because of much stronger absorption lines compared to NIR. The status of QCL devices, system development and applications is reviewed. Special emphasis is given to the situation in Europe where a remarkable growth of QCL related R&D can be observed.

  19. Demonstration of Laser Cutting System for Tube Specimen

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Y. G.; Kim, G. S.; Heo, G. S.; Baik, S. J.; Kim, H. M.; Ahn, S. B. [KAERI, Daejeon (Korea, Republic of)

    2016-05-15

    The oxide layer removal system was also developed because the oxide layer on the surface of the irradiated fuel cladding and components interrupted the applying the electric current during the processing. However, it was found that the mechanical testing data of the irradiated specimens with removal of oxide layer was less reliable than the specimens with oxide layer . The laser cutting system using Nd:YAG with fiber optic beam delivery has great potential in material processing applications of the irradiated fuel cladding and components due to non-contact process. Thus, the oxide layer doesn't interrupt the fabrication process during the laser cutting system. In the present study, the laser cutting system was designed to fabricate the mechanical testing specimens from the unirradiated fuel cladding with and without oxide. The feasibility of the laser cutting system was demonstrated for the fabrication of various types of unirradiated specimens. The effect of surface oxide layer was also investigated for machining process of the zirlo fuel cladding and it was found that laser beam machining could be a useful tool to fabricate the specimens with surface oxide layer. Based on the feasibility studies and demonstration, the design of the laser cutting machine for fully or partially automatic and remotely operable system will be proposed and made.

  20. Optical system for UV-laser technological equipment

    Science.gov (United States)

    Fedosov, Yuri V.; Romanova, Galina E.; Afanasev, Maxim Ya.

    2017-09-01

    Recently there has been an intensive development of intelligent industrial equipment that is highly automated and can be rapidly adjusted for certain details. This equipment can be robotics systems, automatic wrappers and markers, CNC machines and 3D printers. The work equipment considered is the system for selective curing of photopolymers using a UV-laser and UV-radiation in such equipment that leads to additional technical difficulties. In many cases for transporting the radiation from the laser to the point processed, a multi-mirror system is used: however, such systems are usually difficult to adjust. Additionally, such multi-mirror systems are usually used as a part of the equipment for laser cutting of metals using high-power IR-lasers. For the UV-lasers, using many mirrors leads to crucial radiation losses because of many reflections. Therefore, during the development of the optical system for technological equipment using UV-laser we need to solve two main problems: to transfer the radiation for the working point with minimum losses and to include the system for controlling/handling the radiation spot position. We introduce a system for working with UV-lasers with 450mW of power and a wavelength of 0.45 μm based on a fiber system. In our modelling and design, we achieve spot sizes of about 300 μm, and the designed optical and mechanical systems (prototypes) were manufactured and assembled. In this paper, we present the layout of the technological unit, the results of the theoretical modelling of some parts of the system and some experimental results.

  1. Secondary waste characteristics and ITS filtration system on laser cutting

    Energy Technology Data Exchange (ETDEWEB)

    Hara, Kunio; Miyao, Hidehiko [Research Association for Facility Decommissioning (RANDEC), Tokai, Ibaraki (Japan); Nakazawa, Masaharu [Tokyo Univ. (Japan); Kataoka, Shinichi; Nagura, Yasumi; Saiki, Hideo [Mitsubishi Heavy Industries Ltd., Tokyo (Japan)

    2001-03-01

    Technology of dismantling nuclear facilities has been developing in various fields for its evaluation and dismantling system. RANDEC has been studying remote dismantling system for highly activated equipments such as core internals with a laser using optical fiber. Recently a high power YAG laser having the advantage of application for remote dismantling on thick metallic material is the stage for practical use, and narrow kerf can bring the reduction of secondary waste as well. The present paper describes the experimental results and discussion on the laser cutting, including the secondary waste characteristics and its filtration system using the YAG laser. This study has been performed on consignment to RANDEC from the Science and Technology Agency of Japan. (author)

  2. Long distance high power optical laser fiber break detection and continuity monitoring systems and methods

    Science.gov (United States)

    Rinzler, Charles C.; Gray, William C.; Faircloth, Brian O.; Zediker, Mark S.

    2016-02-23

    A monitoring and detection system for use on high power laser systems, long distance high power laser systems and tools for performing high power laser operations. In particular, the monitoring and detection systems provide break detection and continuity protection for performing high power laser operations on, and in, remote and difficult to access locations.

  3. Endovascular brachytherapy to prevent restenosis after angioplasty

    International Nuclear Information System (INIS)

    Wohlgemuth, W.A.; Bohndorf, K.

    2003-01-01

    Endovascular radiotherapy is the first effective prophylaxis of restenosis after percutaneous transluminal angioplasty (PTA) and stenting. The FDA recently approved two devices for the delivery of intracoronary radiation following coronary artery stenting. Published multicenter, double-blind, randomized trials of intracoronary radiation therapy report good results for preventing in-stent restenosis, while the data for the peripheral circulation are still inconclusive. Beta-emitters are easier applicable and probably also safer, whereas gamma-emitters have been more extensively evaluated clinically so far. Primary indication for endovascular brachytherapy are patients at high risk for restenosis, such as previous restenoses, in-stent hyperplasia, long stented segment, long PTA lesion, narrow residual vascular lumen and diabetes. Data from coronary circulation suggest a safety margin of at least 4 to 10 mm at both ends of the angioplastic segment to avoid edge restenosis. To prevent late thrombosis of the treated coronary segment, antiplatelet therapy with clopidogrel and aspirin are recommended for at least 6 months after PTA and for 12 months after a newly implanted stent. An established medication regimen after radiotherapy of peripheral arteries is still lacking. (orig.) [de

  4. A perspective of percutaneous transluminal angioplasty.

    Science.gov (United States)

    Stanson, A W

    1983-01-01

    PTA is a relatively new procedure which is still evolving. More technical improvements are needed. Stiffer balloon plastics and devices to measure arterial wall compliance during balloon inflation are predicted to lead to better long-term success rates. Increasing case numbers provide greater expertise and subsequent refinements in performance and case selection. These factors will lead to improved statistics. Other features of overall patient care must be considered also. The procedure is easy for patients to tolerate, and they can return to activities and work in three or four days. The overall cost is much cheaper than surgery, even at a conservative success rate of 65 percent. There is minimal risk and morbidity, and virtually no mortality. PTA can be repeated if the lesion recurs. Severe complications are rare and almost always surgically treatable. If PTA fails to achieve success, a traditional surgical procedure can be performed. Percutaneous transluminal angioplasty is an important therapeutic alternative to traditional medical and surgical treatment for occlusive arterial disease. It can save legs, veins, time, and money. We need to refine and accurately record the use of this procedure. Total cooperation among clinicians, surgeons, and radiologists is essential for proper utilization of PTA.

  5. Improvement of laser irradiation uniformity in GEKKO XII glass laser system

    International Nuclear Information System (INIS)

    Miyanaga, Noriaki; Matsuoka, Shinichi; Ando, Akinobu; Amano, Shinji; Nakatsuka, Masahiro; Kanabe, Tadashi; Jitsuno, Takahisa; Nakai, Sadao

    1995-01-01

    The uniform laser irradiation is one of key issues in the direct drive laser fusion research. The several key technologies for the uniform laser irradiation are reported. This paper includes the uniformity performance as a result of the introduction of the random phase plate, the partially coherent light and the beam smoothing by spectral dispersion into the New Gekko XI glass laser system. Finally the authors summarize the overall irradiation uniformity on the spherical target surface by considering the power imbalance effect. The technologies developed for the beam smoothing and the power balance control enable them to achieve the irradiation nonuniformities of around 1% level for a foot pulse and of a few % for a main drive pulse, respectively

  6. Power Measurements for Microvision, Inc., Aircrew Integrated Helmet System Scanning Laser Helmet-Mounted Display

    National Research Council Canada - National Science Library

    Rash, Clarence

    2002-01-01

    ...) technology based on scanning lasers. Under this program, Microvision, Inc., Bothell, Washington, has developed a scanning laser HMD prototype for use with the Aircrew Integrated Helmet System (AIHS...

  7. Neutronics of Laser Fission-Fusion Systems

    International Nuclear Information System (INIS)

    Velarde, G.

    1976-01-01

    Neutronics of Fission-Fusion microsystems inertially confined by Lasers are analysed by transport calculation, both stationary (DTF, TIHOC) and time dependent (TDA, TIHEX), discussing the results obtained for the basic parameters of the fission process (multiplication factor, neutron generation time and Rossi-∞). (Author) 14 refs

  8. Nonlinear propagation in fusion laser systems

    International Nuclear Information System (INIS)

    Bliss, E.S.; Glass, A.J.; Glaze, J.A.

    1977-11-01

    This report was assembled to provide a brief review of the historical development of the study of self-focusing and nonlinear light propagation and its impact on the design of large, Nd-glass lasers for fusion research. No claim to completeness is made, but we feel that the enclosed summary does not miss many of the major developments in the field

  9. Neutronics of Laser Fission-Fusion Systems

    Energy Technology Data Exchange (ETDEWEB)

    Velarde, G

    1976-07-01

    Neutronics of Fission-Fusion microsystems inertially confined by Lasers are analysed by transport calculation, both stationary (DTF, TIHOC) and time dependent (TDA, TIHEX), discussing the results obtained for the basic parameters of the fission process (multiplication factor, neutron generation time and Rossi-{infinity}). (Author) 14 refs.

  10. Efficient TEA CO2 laser based coating removal system

    CSIR Research Space (South Africa)

    Prinsloo, FJ

    2007-04-01

    Full Text Available stream_source_info Prinsloo_2007.pdf.txt stream_content_type text/plain stream_size 11617 Content-Encoding UTF-8 stream_name Prinsloo_2007.pdf.txt Content-Type text/plain; charset=UTF-8 Efficient TEA CO2 laser based... by keeping energy density below the damage threshold. The advantage of a pulsed TEA CO2 laser system is that a laser frequency and temporal profile can be chosen to maximize paint removal and concurrently minimize substrate damage. To achieve...

  11. Fiber laser master oscillators for optical synchronization systems

    Energy Technology Data Exchange (ETDEWEB)

    Winter, A.

    2008-04-15

    New X-ray free electron lasers (e.g. the European XFEL) require a new generation of synchronization system to achieve a stability of the FEL pulse, such that pump-probe experiments can fully utilize the ultra-short pulse duration (50 fs). An optical synchronization system has been developed based on the distribution of sub-ps optical pulses in length-stabilized fiber links. The synchronization information is contained in the precise repetition frequency of the optical pulses. In this thesis, the design and characterization of the laser serving as laser master oscillator is presented. An erbium-doped mode-locked fiber laser was chosen. Amplitude and phase noise were measured and record-low values of 0.03 % and 10 fs for the frequency range of 1 kHz to the Nyquist frequency were obtained. Furthermore, an initial proof-of-principle experiment for the optical synchronization system was performed in an accelerator environment. In this experiment, the fiber laser wase phase-locked to a microwave reference oscillator and a 500 meter long fiber link was stabilized to 12 fs rms over a range of 0.1 Hz to 20 kHz. RF signals were obtained from a photodetector without significant degradation at the end of the link. Furthermore, the laser master oscillator for FLASH was designed and is presently in fabrication and the initial infrastructure for the optical synchronization system was setup. (orig.)

  12. Fiber laser master oscillators for optical synchronization systems

    International Nuclear Information System (INIS)

    Winter, A.

    2008-04-01

    New X-ray free electron lasers (e.g. the European XFEL) require a new generation of synchronization system to achieve a stability of the FEL pulse, such that pump-probe experiments can fully utilize the ultra-short pulse duration (50 fs). An optical synchronization system has been developed based on the distribution of sub-ps optical pulses in length-stabilized fiber links. The synchronization information is contained in the precise repetition frequency of the optical pulses. In this thesis, the design and characterization of the laser serving as laser master oscillator is presented. An erbium-doped mode-locked fiber laser was chosen. Amplitude and phase noise were measured and record-low values of 0.03 % and 10 fs for the frequency range of 1 kHz to the Nyquist frequency were obtained. Furthermore, an initial proof-of-principle experiment for the optical synchronization system was performed in an accelerator environment. In this experiment, the fiber laser wase phase-locked to a microwave reference oscillator and a 500 meter long fiber link was stabilized to 12 fs rms over a range of 0.1 Hz to 20 kHz. RF signals were obtained from a photodetector without significant degradation at the end of the link. Furthermore, the laser master oscillator for FLASH was designed and is presently in fabrication and the initial infrastructure for the optical synchronization system was setup. (orig.)

  13. Acousto-optic laser projection systems for displaying TV information

    Energy Technology Data Exchange (ETDEWEB)

    Gulyaev, Yu V [V.A.Kotel' nikov Institute of Radio Engineering and Electronics, Russian Academy of Sciences, Moscow (Russian Federation); Kazaryan, M A [P N Lebedev Physics Institute, Russian Academy of Sciences, Moscow (Russian Federation); Mokrushin, Yu M [D.V. Efremov Scientific Research Institute of Electrophysical Apparatus (Russian Federation); Shakin, O V [Ioffe Physical Technical Institute, Russian Academy of Sciences, St. Petersburg (Russian Federation)

    2015-04-30

    This review addresses various approaches to television projection imaging on large screens using lasers. Results are presented of theoretical and experimental studies of an acousto-optic projection system operating on the principle of projecting an image of an entire amplitude-modulated television line in a single laser pulse. We consider characteristic features of image formation in such a system and the requirements for its individual components. Particular attention is paid to nonlinear distortions of the image signal, which show up most severely at low modulation signal frequencies. We discuss the feasibility of improving the process efficiency and image quality using acousto-optic modulators and pulsed lasers. Real-time projectors with pulsed line imaging can be used for controlling high-intensity laser radiation. (review)

  14. Acousto-optic laser projection systems for displaying TV information

    International Nuclear Information System (INIS)

    Gulyaev, Yu V; Kazaryan, M A; Mokrushin, Yu M; Shakin, O V

    2015-01-01

    This review addresses various approaches to television projection imaging on large screens using lasers. Results are presented of theoretical and experimental studies of an acousto-optic projection system operating on the principle of projecting an image of an entire amplitude-modulated television line in a single laser pulse. We consider characteristic features of image formation in such a system and the requirements for its individual components. Particular attention is paid to nonlinear distortions of the image signal, which show up most severely at low modulation signal frequencies. We discuss the feasibility of improving the process efficiency and image quality using acousto-optic modulators and pulsed lasers. Real-time projectors with pulsed line imaging can be used for controlling high-intensity laser radiation. (review)

  15. Acousto-optic laser projection systems for displaying TV information

    Science.gov (United States)

    Gulyaev, Yu V.; Kazaryan, M. A.; Mokrushin, Yu M.; Shakin, O. V.

    2015-04-01

    This review addresses various approaches to television projection imaging on large screens using lasers. Results are presented of theoretical and experimental studies of an acousto-optic projection system operating on the principle of projecting an image of an entire amplitude-modulated television line in a single laser pulse. We consider characteristic features of image formation in such a system and the requirements for its individual components. Particular attention is paid to nonlinear distortions of the image signal, which show up most severely at low modulation signal frequencies. We discuss the feasibility of improving the process efficiency and image quality using acousto-optic modulators and pulsed lasers. Real-time projectors with pulsed line imaging can be used for controlling high-intensity laser radiation.

  16. Mid-IR laser system for advanced neurosurgery

    Science.gov (United States)

    Klosner, M.; Wu, C.; Heller, D. F.

    2014-03-01

    We present work on a laser system operating in the near- and mid-IR spectral regions, having output characteristics designed to be optimal for cutting various tissue types. We provide a brief overview of laser-tissue interactions and the importance of controlling certain properties of the light beam. We describe the principle of operation of the laser system, which is generally based on a wavelength-tunable alexandrite laser oscillator/amplifier, and multiple Raman conversion stages. This configuration provides robust access to the mid-IR spectral region at wavelengths, pulse energies, pulse durations, and repetition rates that are attractive for neurosurgical applications. We summarize results for ultra-precise selective cutting of nerve sheaths and retinas with little collateral damage; this has applications in procedures such as optic-nerve-sheath fenestration and possible spinal repair. We also report results for cutting cornea, and dermal tissues.

  17. The Final Focus Test Beam laser referene system

    International Nuclear Information System (INIS)

    Bressler, V.E.; Ruland, R.E.

    1993-05-01

    The original design for the SLAC linac included an alignment reference system with 270 diffraction gratings situated along the 3000 meter linac. These gratings have provided SLAC with a global reference line repeatable to within 200 micro meters. For the Final Focus Test Beam, this laser system has been extended and 13 new diffraction gratings have been installed. Improvements targets and the availability of new instruments allows us to evaluate the performance of the laser reference system at the 510 micro meter level. An explanation of the system and the results of our evaluation are presented

  18. Wavelength stabilized multi-kW diode laser systems

    Science.gov (United States)

    Köhler, Bernd; Unger, Andreas; Kindervater, Tobias; Drovs, Simon; Wolf, Paul; Hubrich, Ralf; Beczkowiak, Anna; Auch, Stefan; Müntz, Holger; Biesenbach, Jens

    2015-03-01

    We report on wavelength stabilized high-power diode laser systems with enhanced spectral brightness by means of Volume Holographic Gratings. High-power diode laser modules typically have a relatively broad spectral width of about 3 to 6 nm. In addition the center wavelength shifts by changing the temperature and the driving current, which is obstructive for pumping applications with small absorption bandwidths. Wavelength stabilization of high-power diode laser systems is an important method to increase the efficiency of diode pumped solid-state lasers. It also enables power scaling by dense wavelength multiplexing. To ensure a wide locking range and efficient wavelength stabilization the parameters of the Volume Holographic Grating and the parameters of the diode laser bar have to be adapted carefully. Important parameters are the reflectivity of the Volume Holographic Grating, the reflectivity of the diode laser bar as well as its angular and spectral emission characteristics. In this paper we present detailed data on wavelength stabilized diode laser systems with and without fiber coupling in the spectral range from 634 nm up to 1533 nm. The maximum output power of 2.7 kW was measured for a fiber coupled system (1000 μm, NA 0.22), which was stabilized at a wavelength of 969 nm with a spectral width of only 0.6 nm (90% value). Another example is a narrow line-width diode laser stack, which was stabilized at a wavelength of 1533 nm with a spectral bandwidth below 1 nm and an output power of 835 W.

  19. Clinical experience with the Monorail balloon catheter for coronary angioplasty.

    Science.gov (United States)

    Finci, L; Meier, B; Roy, P; Steffenino, G; Rutishauser, W

    1988-01-01

    The Monorail balloon catheter is distinctly different from other current balloon catheters: the guidewire passes through the balloon itself, exits the catheter proximal to the balloon, and runs alongside its small shaft (3 French) through the guiding catheter. Monorail coronary angioplasty was attempted in 61 patients on 73 lesions with balloons from 2.0 to 3.7 mm. Angiographic success was obtained in 66 lesions (90%). For 15 lesions, balloon exchanges were needed. In three lesions, the Monorail balloon failed to cross the lesion, while a standard balloon succeeded; two lesions could not be crossed with any balloon. Vessel occlusion occurred in four patients: two had emergency surgery without infarct (one died suddenly 4 days later and one had a stroke 1 day later), one was recanalized with a standard balloon, and one had a myocardial infarct. Continuous infusion of urokinase was used until patient 3 in whom problems with the delivery system led to cardiocerebral air embolization (with complete recovery). No thrombotic complications were observed in the subsequent 58 patients with only a bolus of 10,000 U of heparin. The Monorail balloon facilitates contrast injections and balloon exchanges but appears more difficult to pass through tight lesions. Omission of the previously recommended infusion with a thrombolytic agent proved safe.

  20. Development of a Laser Induced Fluorescence (LIF) System with a Tunable Diode Laser

    International Nuclear Information System (INIS)

    Woo, Hyun Jong; Do, Jeong Jun; You, Hyun Jong; Choi, Geun Sik; Lee, Myoung Jae; Chung, Kyu Sun

    2005-01-01

    The Laser Induced Fluorescence (LIF) is known as one of the most powerful techniques for measurements of ion velocity distribution function (IVDF) and ion temperature by means of Doppler broadening and Doppler shift. The dye lasers are generally used for LIF system with 611.66 nm (in vac.) for Ar ion, the low power diode laser was also proposed by Severn et al with the wavelength of 664.55 nm and 668.61 nm (in vac.) for Ar ion. Although the diode laser has the disadvantages of low power and small tuning range, it can be used for LIF system at the low temperature plasmas. A tunable diode laser with 668.614 nm of center wavelength and 10 GHz mode hop free tuning region has been used for our LIF system and it can be measured the ion temperature is up to 1 eV. The ion temperature and velocity distribution function have been measured with LaB6 plasma source, which is about 0.23 eV with Ar gas and 2.2 mTorr working pressure

  1. Optimized laser system for decontamination of painted surfaces

    International Nuclear Information System (INIS)

    Champonnois, F.; Lascoutouna, C.; Long, H.; Thro, P.Y.; Mauchien, P.

    2010-01-01

    Laser systems have long been seen as potentially very interesting for removing contamination from surfaces. The main expected advantages are the possibility of remote process and the absence of secondary waste. However these systems were unable to find their way to an industrial deployment due to the lack of reliability of the laser and the difficulty to satisfactory collect the (contaminated) ablated matter. In this contribution we report on a compact, reliable and efficient laser decontaminating system called ASPILASERO. It is adapted to the constraints bound to a nuclear environment. It takes advantages of the recent progress made by the fibre lasers which have now a lifetime longer than 20000 hours without maintenance. The collecting system collects all the removed matter (gases and aerosols) on nuclear grade filters. The fully automated system has been successfully tested on a vertical wall of a stopped nuclear installation. It has demonstrated an efficiency of 1 m 2 /hr which is in the same order of other classical techniques but with a much lower quantity of waste and the ability to work continuously without human intervention. Measurements performed after the laser treatment have shown that the contamination was completely removed by removing the paint and that this contamination was not re-deposited elsewhere on the wall. The system will also be used in highly contaminated hot cells to decrease the radiation and allow maintenance or refurbishing in safe working conditions. (authors)

  2. Development of tunable flashlamp excited dye laser system

    International Nuclear Information System (INIS)

    Bhanthumnavin, V.; Apikitmata, S.; Kochareon, P.

    1991-01-01

    A tunable flashlamp excited dye laser (FEDL) was successfully developed for the first time in Thailand by Thai scientists at KMIT Thonburi (Bangmod). The Rhodamine 6G dissolved in ethyl alcohol was utilized as a laser medium and circulated by a pump through a laser head. The dye cuvette had an inner diameter of 4.0 mm and was 90 mm long. The cavity mirrors M 1 , and M 2 were concave mirrors with reflectivities of 100% and 73% respectively. A power supply of 0-20 kV and current of 0-50 mA charged a capacitor of 0.3 μ f at 10-15 kV which was then discharged via a spark gap through the flashlamp. The output laser wavelengths was tunable from λ = 550-640 nm. It is the first FEDL system, locally developed, which has a tunable wavelength for the laser output. The laser pulse width is about 1.0 μs with energy of 20 mJ and peak power pf 20 KW. The repetition rate of the laser is 1/15 Hz. (author). 14 refs, 7 figs

  3. Development of an integrated automated retinal surgical laser system.

    Science.gov (United States)

    Barrett, S F; Wright, C H; Oberg, E D; Rockwell, B A; Cain, C; Rylander, H G; Welch, A J

    1996-01-01

    Researchers at the University of Texas and the USAF Academy have worked toward the development of a retinal robotic laser system. The overall goal of this ongoing project is to precisely place and control the depth of laser lesions for the treatment of various retinal diseases such as diabetic retinopathy and retinal tears. Separate low speed prototype subsystems have been developed to control lesion depth using lesion reflectance feedback parameters and lesion placement using retinal vessels as tracking landmarks. Both subsystems have been successfully demonstrated in vivo on pigmented rabbits using an argon continuous wave laser. Preliminary testing on rhesus primate subjects have been accomplished with the CW argon laser and also the ultrashort pulse laser. Recent efforts have concentrated on combining the two subsystems into a single prototype capable of simultaneously controlling both lesion depth and placement. We have designated this combined system CALOSOS for Computer Aided Laser Optics System for Ophthalmic Surgery. Several interesting areas of study have developed in integrating the two subsystems: 1) "doughnut" shaped lesions that occur under certain combinations of laser power, spot size, and irradiation time complicating measurements of central lesion reflectance, 2) the optimal retinal field of view (FOV) to achieve both tracking and lesion parameter control, and 3) development of a hybrid analog/digital tracker using confocal reflectometry to achieve retinal tracking speeds of up to 100 dgs. This presentation will discuss these design issues of this clinically significant prototype system. Details of the hybrid prototype system are provided in "Hybrid Eye Tracking for Computer-Aided Retinal Surgery" at this conference. The paper will close with remaining technical hurdles to clear prior to testing the full-up clinical prototype system.

  4. A noncontact laser system for measuring soil surface topography

    International Nuclear Information System (INIS)

    Huang, C.; White, I.; Thwaite, E.G.; Bendeli, A.

    1988-01-01

    Soil surface topography profoundly influences runoff hydrodynamics, soil erosion, and surface retention of water. Here we describe an optical noncontact system for measuring soil surface topography. Soil elevation is measured by projecting a laser beam onto the surface and detecting the position of the interception point. The optical axis of the detection system is oriented at a small angle to the incident beam. A low-power HeNe (Helium-Neon) laser is used as the laser source, a photodiode array is used as the laser image detector and an ordinary 35-mm single lens reflex camera provides the optical system to focus the laser image onto the diode array. A wide spectrum of measurement ranges (R) and resolutions are selectable, from 1 mm to 1 m. These are determined by the laser-camera distance and angle, the focal length of the lens, and the sensing length of the diode array and the number of elements (N) contained in the array. The resolution of the system is approximately R/2N. We show for the system used here that this resolution is approximately 0.2%. In the configuration selected, elevation changes of 0.16 mm could be detected over a surface elevation range of 87 mm. The sampling rate of the system is 1000 Hz, which permits soil surfaces to be measured at speeds of up to 1 m s −1 with measurements taken at 1-mm spacing. Measurements of individual raindrop impacts on the soil and of soil surfaces before and after rain show the versatility of the laser surface profiler, which has applications in studies of erosion processes, surface storage and soil trafficability

  5. Balloon angioplasty in acute and chronic coronary artery disease

    International Nuclear Information System (INIS)

    Holmes, D.R. Jr.; Vlietstra, R.E.

    1989-01-01

    Percutaneous transluminal coronary angioplasty has grown exponentially since its introduction. Currently, selection criteria include single-vessel and multivessel disease, stable and unstable angina, and acute infarction. The outcome depends on specific patient and antiographic characteristics. In ideal lesions, success rates should be greater than 90%, with low morbidity and mortality. With more severe and diffuse multivessel disease, success rates are lower and complication rates are higher. In these cases, percutaneous transluminal coronary angioplasty still offers a reasonable option, provided complete revascularization can be achieved or the angina-producing lesion dilated. Numerous issues remain unresolved, including (1) the role of percutaneous transluminal coronary angioplasty vs coronary surgery (currently being tested), (2) restenosis, which occurs in approximately 30% of treated lesions, and (3) organizational adjustments such as training and certification to maintain high standards of care

  6. Field-Testing of an Active Laser Tracking System

    Science.gov (United States)

    Markov, V.; Khiznyak, A.; Woll, D.; Liu, S.

    Comprehensive space surveillance demands a more accurate technique in tracking multi-dimensional state vector (3D coordinate, velocity, vibration, etc.) of the space objects. RF radiometric techniques typically can not provide the needed accuracy, while passive optical (and laser) tracking systems can provide distance to the object and its angular position, but not a direct reading of velocity, the parameter of primary importance for space object tracking and characterization. Addressing this problem with active optical tracking techniques is challenging because of the great distances involved, the high velocity of the satellites, and the optical aberrations induced by the atmosphere. We have proposed a phase conjugation based laser tracking concept, and accomplished the first version of design and engineering of a prototype for an Active Laser Tracking System (ALTS). In its current state the ALTS is capable to demonstrate the very basics operational principles of the proposed active tracking technique. We then performed a number of experiments to prove operational capabilities of this prototype both at MetroLaser's lab environment and at Edwards AFB Test Range. In its current architecture the ALTS is comprised of two laser cavities, Master and Slave that are coupled through a Phase Conjugate Mirror (PCM) formed in a non-linear medium (NLM) set at Master laser cavity. By pumping NLM and forming PCM, Master laser establishes the cavities coupling mode and injects the photons in the slave cavity. It is essential that the specific features of the PCM not only serve to couple ALTS cavities, but also serves to compensate optical aberrations of the ALTS (gain media and optical elements of the laser resonator). Due to its ability to compensate optical aberrations, phase conjugate resonators are capable of sustaining oscillation with a remote target as an output coupler. The entire system comprises of several modules, including a laser, emitting/receiving telescope, gimbal

  7. Uses of ORACLE in the Nova Laser Control System

    International Nuclear Information System (INIS)

    McGuigan, D.L.

    1983-01-01

    The Nova Laser System is a large-scale fusion experiment being constructed at the Lawrence Livermore National Laboratory. Modern control system technology is required to efficiently manage the thousands of devices needed to operate the system. In order to reduce the requirements on the operations staff, much of the system is being automated. This requires a significant knowledge base including frequently used system configurations and device parameters. We will be using ORACLE to provide this information to the control system. To insure the control-system integrity, ORACLE will be used to maintain information about the control-system software. This information will be used to document the system as well as help track down problems. ORACLE will also be used to maintain data on the system performance. This data will be analyzed to optimize the laser performance and point out when maintenance is required

  8. Angioplasty or Stenting of Extra- and Intracranial Vertebral Artery Stenoses

    International Nuclear Information System (INIS)

    Hauth, Elke A.M.; Gissler, H. Martin; Drescher, Robert; Jansen, Christian; Jaeger, Horst J.; Mathias, Klaus D.

    2004-01-01

    Purpose: To determine the feasibility and safety of angioplasty or angioplasty and stenting of extra- and intracranial vertebral artery (VA) stenosis. Methods: In 16 consecutive patients (9 men, 7 women; mean age 61 years, range 49-74 years) 16 stenotic VAs were treated with angioplasty orangioplasty and stenting. Eleven stenoses were localized in V1 segment,1 stenosis in V2 segment and 4 stenoses in V4 segment of VA. Fourteen VA stenoses were symptomatic, 2 asymptomatic. The etiology of the stenoses was atherosclerotic in all cases. Results:Angioplasty was performed in 8 of 11 V1 and 2 of 4 V4 segments of the VA. In 3 of 11 V1 segments and 2 of 4 V4 segments of the VA we combined angioplasty with stenting. The procedures were successfully performed in 14 of 16 VAs (87%). Complications were asymptomatic vessel dissection resulting in vessel occlusion in 1 of 11 V1 segments and asymptomatic vessel dissection in 2 of 4 V4 segments of the VA. One patient died in the 24-hr period after the procedure because of subarachnoid hemorrhage as a complication following vessel perforation of the treated V4 segment. Conclusion: Angioplasty orangioplasty and stenting of extracranial VA stenoses can be performed with a high technical success rate and a low complication rate. In intracranial VA stenosis the procedure is technically feasible but complications can be life-threatening. The durability and procedural complication rates of primary stenting without using predilation in extra- and intracranial VA stenosis should be defined in the future

  9. A 1-kJ KrF laser system for laser fusion research

    International Nuclear Information System (INIS)

    Owadano, Y.; Okuda, I.; Tanimoto, M.; Matsumoto, Y.; Yaoita, A.; Komeiji, S.; Yano, M.

    1987-01-01

    Ultraviolet laser light has several advantages in coupling with a laser fusion target, and the KrF laser is considered to be a promising candidate for the driver because of its short wavelength, high overall efficiency, and scalability to a megajoule class system. The Electrotechnical Laboratory is developing a 1-kJ class KrF laser system to perform target-shooting experiments in the 10/sup 13/-10/sup 15/-W/cm/sup 2/, 10-20-ns range and to investigate the possibility of a compact laser fusion driver which operates at a high pumping density and high laser power density. Based on the pulsed-power technology used in Amp2 and the characteristics of the Kr-rich mixture measured, Amp3 was designed to operate at high optical power density with a Kr-rich mixture. Amp3 has four PFLs charged by a single 40-kJ Marx generator and four e-beam diodes (550 kV, 4 Ω) arranged cylindrically around the laser cell. The active volume is 660 cm/sup 2/ (29 cm in diameter) X 1 m, and 2-atm Kr is pumped at a density of 1.9 MW/cm/sup 3/. Output energy of 1 kJ is expected at an intrinsic efficiency of 8.3% and overall efficiency of 2.5%. Output energy fluence is 1.5 J/cm/sup 2/ (15 MW/cm/sup 2/) on average, which is lower than the damage threshold of our fully reflecting AR coatings (>3 J/cm/sup 2/)

  10. Development of Blue Laser Direct-Write Lithography System

    Directory of Open Access Journals (Sweden)

    Hao-Wen Chang

    2012-01-01

    Full Text Available The optical lithography system researched in this study adopted the laser direct-write lithography technology with nano-positioning stage by using retailing blue ray optical pickup head contained 405nm wavelength and 0.85 numerical aperture of focus lens as the system lighting source. The system employed a photodiode received the focusing error signal reflected by the glass substrate to identify specimen position and automatic focused control with voice coil motor. The pattern substrate was loaded on a nano-positioning stage; input pattern path automatically and collocate with inner program at the same time. This research has successfully developed a blue laser lithography process system. The single spot size can be narrowed down to 3.07 μm and the linewidth is 3.3μm, time of laser control can reach to 450 ns and the exposure pattern can be controlled by program as well.

  11. University of Hawaii Lure Observatory. [lunar laser ranging system construction

    Science.gov (United States)

    Carter, W. E.; Williams, J. D.

    1973-01-01

    The University of Hawaii's Institute for Astronomy is currently constructing a lunar laser ranging observatory at the 3050-meter summit of Mt. Haleakala, Hawaii. The Nd YAG laser system to be employed provides three pulses per second, each pulse being approximately 200 picoseconds in duration. The energy contained in one pulse at 5320 A lies in the range from 250 to 350 millijoules. Details of observatory construction are provided together with transmitter design data and information concerning the lunastat, the feed telescope, the relative pointing system, the receiver, and the event timer system.

  12. Fiber optic coherent laser radar 3d vision system

    International Nuclear Information System (INIS)

    Sebastian, R.L.; Clark, R.B.; Simonson, D.L.

    1994-01-01

    Recent advances in fiber optic component technology and digital processing components have enabled the development of a new 3D vision system based upon a fiber optic FMCW coherent laser radar. The approach includes a compact scanner with no moving parts capable of randomly addressing all pixels. The system maintains the immunity to lighting and surface shading conditions which is characteristic of coherent laser radar. The random pixel addressability allows concentration of scanning and processing on the active areas of a scene, as is done by the human eye-brain system

  13. Measurement system with high accuracy for laser beam quality.

    Science.gov (United States)

    Ke, Yi; Zeng, Ciling; Xie, Peiyuan; Jiang, Qingshan; Liang, Ke; Yang, Zhenyu; Zhao, Ming

    2015-05-20

    Presently, most of the laser beam quality measurement system collimates the optical path manually with low efficiency and low repeatability. To solve these problems, this paper proposed a new collimated method to improve the reliability and accuracy of the measurement results. The system accuracy controlled the position of the mirror to change laser beam propagation direction, which can realize the beam perpendicularly incident to the photosurface of camera. The experiment results show that the proposed system has good repeatability and the measuring deviation of M2 factor is less than 0.6%.

  14. Laser fusion systems design study. Final technical report

    International Nuclear Information System (INIS)

    1975-06-01

    This study investigated: (1) the formulation and evaluation of an alignment system to accomplish pointing, focusing, centering and translation for the 20-arm SHIVA laser, (2) the formulation and evaluation of concepts for the correction of static phase distortions introduced by the accumulated optical elements in the laser chains, (3) the formulation and evaluation of concepts for the correction of optical path length differences between the arms of the SHIVA system, and (4) the conceptual design of appropriate control system hardware. (U.S.)

  15. Subclavian steal syndrome: treatment by percutaneous transluminal angioplasty

    International Nuclear Information System (INIS)

    Abath, Carlos Gustavo Coutinho; Silva, Marcos Antonio Barbosa da; Brito, Norma Maria Tenorio; Marques, Silvio Romero; Santa Cruz, Rodolfo

    1995-01-01

    The subclavian steal syndrome is a rare vascular disease that can be managed by interventional radiology. It is presented the experience with three cases of this syndrome that underwent percutaneous transluminal angioplasty, and a brief literature review is done. Two patients remained asymptomatic 23 and 30 months, respectively, after the procedure. One patient presented with recurrent symptoms 12 months after the dilatation. Considering the low morbidity and good clinical and technical results, percutaneous transluminal angioplasty is the first choice in the subclavian steal syndrome treatment. (author). 9 refs., 3 figs

  16. Method of laser beam coding for control systems

    Science.gov (United States)

    Pałys, Tomasz; Arciuch, Artur; Walczak, Andrzej; Murawski, Krzysztof

    2017-08-01

    The article presents the method of encoding a laser beam for control systems. The experiments were performed using a red laser emitting source with a wavelength of λ = 650 nm and a power of P ≍ 3 mW. The aim of the study was to develop methods of modulation and demodulation of the laser beam. Results of research, in which we determined the effect of selected camera parameters, such as image resolution, number of frames per second on the result of demodulation of optical signal, is also shown in the paper. The experiments showed that the adopted coding method provides sufficient information encoded in a single laser beam (36 codes with the effectiveness of decoding at 99.9%).

  17. Requirements and new materials for fusion laser systems

    International Nuclear Information System (INIS)

    Stokowski, S.E.; Weber, M.J.; Saroyan, R.A.; Hagen, W.F.

    1977-10-01

    Higher focusable power in neodymium glass fusion lasers can be obtained through the use of new materials with lower nonlinear index (n 2 ) and better energy storage capabilities than the presently employed silicate glass. Silicate, phosphate, fluorophosphate, and beryllium fluoride glasses are discussed in terms of fusion laser requirements, particularly those for the proposed Nova laser. Examples of the variation in spectroscopic and optical properties obtainable with compositional changes are given. Results of a system evaluation of potential laser materials show that fluorophosphate glasses have many of the desired properties for use in Nova. These glasses are now being cast in large sizes (30-cm diameter) and will be tested in prototype amplifiers in 1978

  18. Requirements and new materials for fusion laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Stokowski, S.E.; Weber, M.J.; Saroyan, R.A.; Hagen, W.F.

    1977-10-01

    Higher focusable power in neodymium glass fusion lasers can be obtained through the use of new materials with lower nonlinear index (n/sub 2/) and better energy storage capabilities than the presently employed silicate glass. Silicate, phosphate, fluorophosphate, and beryllium fluoride glasses are discussed in terms of fusion laser requirements, particularly those for the proposed Nova laser. Examples of the variation in spectroscopic and optical properties obtainable with compositional changes are given. Results of a system evaluation of potential laser materials show that fluorophosphate glasses have many of the desired properties for use in Nova. These glasses are now being cast in large sizes (30-cm diameter) and will be tested in prototype amplifiers in 1978.

  19. Stretchers and compressors for ultra-high power laser systems

    Energy Technology Data Exchange (ETDEWEB)

    Yakovlev, I V [Institute of Applied Physics, Russian Academy of Sciences, Nizhnii Novgorod (Russian Federation)

    2014-05-30

    This review is concerned with pulse stretchers and compressors as key components of ultra-high power laser facilities that take advantage of chirped-pulse amplification. The potentialities, characteristics, configurations and methods for the matching and alignment of these devices are examined, with particular attention to the history of the optics of ultra-short, ultra-intense pulses before and after 1985, when the chirped-pulse amplification method was proposed, which drastically changed the view of the feasibility of creating ultra-high power laser sources. The review is intended primarily for young scientists and experts who begin to address the amplification and compression of chirped pulses, experts in laser optics and all who are interested in scientific achievements in the field of ultra-high power laser systems. (review)

  20. Apparatus, system, and method for laser-induced breakdown spectroscopy

    Science.gov (United States)

    Effenberger, Jr., Andrew J; Scott, Jill R; McJunkin, Timothy R

    2014-11-18

    In laser-induced breakdown spectroscopy (LIBS), an apparatus includes a pulsed laser configured to generate a pulsed laser signal toward a sample, a constructive interference object and an optical element, each located in a path of light from the sample. The constructive interference object is configured to generate constructive interference patterns of the light. The optical element is configured to disperse the light. A LIBS system includes a first and a second optical element, and a data acquisition module. The data acquisition module is configured to determine an isotope measurement based, at least in part, on light received by an image sensor from the first and second optical elements. A method for performing LIBS includes generating a pulsed laser on a sample to generate light from a plasma, generating constructive interference patterns of the light, and dispersing the light into a plurality of wavelengths.

  1. Recent developments in retinal lasers and delivery systems

    Directory of Open Access Journals (Sweden)

    Naresh Kumar Yadav

    2014-01-01

    Full Text Available Photocoagulation is the standard of care for several ocular disorders and in particular retinal conditions. Technology has offered us newer lasing mediums, wavelengths and delivery systems. Pattern scan laser in proliferative diabetic retinopathy and diabetic macular edema allows laser treatment that is less time consuming and less painful. Now, it is possible to deliver a subthreshold micropulse laser that is above the threshold of biochemical effect but below the threshold of a visible, destructive lesion thereby preventing collateral damage. The advent of solid-state diode yellow laser allows us to treat closer to the fovea, is more effective for vascular structures and offers a more uniform effect in patients with light or irregular fundus pigmentation. Newer retinal photocoagulation options along with their advantages is discussed in this review.

  2. BENCHMARKING MOBILE LASER SCANNING SYSTEMS USING A PERMANENT TEST FIELD

    Directory of Open Access Journals (Sweden)

    H. Kaartinen

    2012-07-01

    Full Text Available The objective of the study was to benchmark the geometric accuracy of mobile laser scanning (MLS systems using a permanent test field under good coverage of GNSS. Mobile laser scanning, also called mobile terrestrial laser scanning, is currently a rapidly developing area in laser scanning where laser scanners, GNSS and IMU are mounted onboard a moving vehicle. MLS can be considered to fill the gap between airborne and terrestrial laser scanning. Data provided by MLS systems can be characterized with the following technical parameters: a point density in the range of 100-1000 points per m2 at 10 m distance, b distance measurement accuracy of 2-5 cm, and c operational scanning range from 1 to 100 m. Several commercial, including e.g. Riegl, Optech and others, and some research mobile laser scanning systems surveyed the test field using predefined driving speed and directions. The acquired georeferenced point clouds were delivered for analyzing. The geometric accuracy of the point clouds was determined using the reference targets that could be identified and measured from the point cloud. Results show that in good GNSS conditions most systems can reach an accuracy of 2 cm both in plane and elevation. The accuracy of a low cost system, the price of which is less than tenth of the other systems, seems to be within a few centimetres at least in ground elevation determination. Inaccuracies in the relative orientation of the instruments lead to systematic errors and when several scanners are used, in multiple reproductions of the objects. Mobile laser scanning systems can collect high density point cloud data with high accuracy. A permanent test field suits well for verifying and comparing the performance of different mobile laser scanning systems. The accuracy of the relative orientation between the mapping instruments needs more attention. For example, if the object is seen double in the point cloud due to imperfect boresight calibration between two

  3. A supervisor system for computer aided laser machining

    International Nuclear Information System (INIS)

    Mukherjee, J.K.

    1990-01-01

    Lasers achieve non divergent beam of short wavelength energy which can propagate through normal atmosphere with little divergence and can be focused on very fine points. The final high energy per unit area on target is highly localised and suitable for various types of machining at high speeds. The most notable factor is that this high energy spot can be located precisely using light-weight optical components. The laser-machining is very amenable to environmental conditions unlike electron beam and other techniques. Precision cutting and welding of nuclear materials in normal or non oxidising atmosphere can be done using this fairly easily. To achieve these objectives, development of a computer controlled laser machining system has been undertaken. The development project aims at building a computer aided machine with indegenous controller and medium power laser suitable for cutting, welding, and marking. This paper describes the integration of the various computer aided functions, spanning over the full range, from job-defining to final finished part-delivary, in computer aided laser machining. Various innovative features of the system that render it suitable for laser tool development as well as for special machining applications with user-friendliness have been covered. (author). 5 refs., 5 figs

  4. The design of laser atmosphere transmission characteristic measurement system based on virtual instrument

    Science.gov (United States)

    Zhang, Laixian; Sun, Huayan; Xu, Jiawen

    2010-10-01

    The laser atmosphere transmission characteristic affects the use of laser in engineering greatly. This paper designed a laser atmosphere transmission characteristic measurement system based on LabVIEW software, a product of NI. The system acquires laser spacial distribution by means of controlling NI image acquisition card and CCD through PCI, controls oscillograph to acquire laser time domain distribution through Ethernet and controls power meter to acquire energy of laser through RS-232. It processes the data acquired and analyses the laser atmosphere transmission characteristic using Matlab, which is powerful in data processing, through software interface. It provided a new way to study the laser atmosphere transmission characteristic.

  5. Applications of OALCLV in the high power laser systems

    Science.gov (United States)

    Huang, Dajie; Fan, Wei; Cheng, He; Wei, Hui; Wang, Jiangfeng; An, Honghai; Wang, Chao; Cheng, Yu; Xia, Gang; Li, Xuechun; Lin, Zunqi

    2017-10-01

    This paper introduces the recent development of our integrated optical addressed spatial light modulator and its applications in the high power laser systems. It can be used to convert the incident beam into uniform beam for high energy effiency, or it can realize special distribution to meet the requirements of physical experiment. The optical addressing method can avoid the problem of the black matrix effect of the electric addressing device. Its transmittance for 1053nm light is about 85% and the aperture of our device has reached 22mm× 22mm. As a transmissive device, it can be inserted into the system without affecting the original optical path. The applications of the device in the three laser systems are introduced in detail in this paper. In the SGII-Up laser facility, this device demonstrates its ability to shape the output laser beam of the fundamental frequency when the output energy reaches about 2000J. Meanwhile, there's no change in the time waveform and far field distribution. This means that it can effectively improve the capacity of the maximum output energy. In the 1J1Hz Nd-glass laser system, this device has been used to improve the uniformity of the output beam. As a result, the PV value reduces from 1.4 to 1.2, which means the beam quality has been improved effectively. In the 9th beam of SGII laser facility, the device has been used to meet the requirements of sampling the probe light. As the transmittance distribution of the laser beam can be adjusted, the sampling spot can be realized in real time. As a result, it's easy to make the sampled spot meet the requirements of physics experiment.

  6. Laser rangefinders for autonomous intelligent cruise control systems

    Science.gov (United States)

    Journet, Bernard A.; Bazin, Gaelle

    1998-01-01

    THe purpose of this paper is to show to what kind of application laser range-finders can be used inside Autonomous Intelligent Cruise Control systems. Even if laser systems present good performances the safety and technical considerations are very restrictive. As the system is used in the outside, the emitted average output power must respect the rather low level of 1A class. Obstacle detection or collision avoidance require a 200 meters range. Moreover bad weather conditions, like rain or fog, ar disastrous. We have conducted measurements on laser rangefinder using different targets and at different distances. We can infer that except for cooperative targets low power laser rangefinder are not powerful enough for long distance measurement. Radars, like 77 GHz systems, are better adapted to such cases. But in case of short distances measurement, range around 10 meters, with a minimum distance around twenty centimeters, laser rangefinders are really useful with good resolution and rather low cost. Applications can have the following of white lines on the road, the target being easily cooperative, detection of vehicles in the vicinity, that means car convoy traffic control or parking assistance, the target surface being indifferent at short distances.

  7. Operative and economic evaluation of a 'Laser Printer Multimodality' System

    International Nuclear Information System (INIS)

    Battaglia, G.; Moscatelli, G.; Maroldi, R.; Chiesa, A.

    1991-01-01

    The increasing application of digital techniques to diagnostic imaging is causing significant changes in several related activities, such as a reproduction of digital images on film. In the Department of Diagnostic Imaging of the University of Brescia, about 70% of the whole of images are produced by digital techniques; at present, most of these images are reproduced on film with a Multimodality System interfacing CT, MR, DSA, and DR units with a single laser printer. Our analysis evaluates the operative and economics aspects of image reproduction, by comparing the 'single cassette' multiformat Camera and the Laser Printer Multimodality SAystem. Our results point out the advantages obtained by reproducing images with a Laser Printer Multimodality System: outstanding quality, reproduction of multiple originals, and marked reduction in the time needed for both image archiving and film handling. The Laser Printer Multimodality System allows over 5 hours/day to be saved -that is to say the working day of an operator, who can be thus shifted to other functions. The important economic aspect of the reproduction of digital images on film proves the Laser Printer Multimodality System to have some advantage over Cameras

  8. Designing, modeling and controlling a novel autonomous laser weeding system

    DEFF Research Database (Denmark)

    Shahrak Nadimi, Esmaeil; Andersson, Kim Johan; Jørgensen, Rasmus Nyholm

    2009-01-01

      Abstract: in this paper, the process of designing and developing a novel laser weeding test setup is explained. The main purpose of designing this system was to simulate the dynamic field conditions of a mobile vehicle capable of targeting weeds. This system consists of a rig containing three...

  9. High Power laser power conditioning system new discharge circuit research

    CERN Document Server

    Li Yi; Peng Han Sheng; Zhou Pei Zhang; Zheng Wan Guo; Guo Lang Fu; Chen Li Hua; Chen De Hui; Lai Gui You; Luan Yong Ping

    2002-01-01

    The new discharge circuit of power conditioning system for high power laser is studied. The theoretical model of the main discharge circuit is established. The pre-ionization circuit is studied in experiment. In addition, the explosion energy of the new large xenon lamp is successfully measured. The conclusion has been applied to 4 x 2 amplifier system

  10. Semiconductor Mode-Locked Lasers for Optical Communication Systems

    DEFF Research Database (Denmark)

    Yvind, Kresten

    2003-01-01

    The thesis deals with the design and fabrication of semiconductor mode-locked lasers for use in optical communication systems. The properties of pulse sources and characterization methods are described as well as requirements for application in communication systems. Especially, the importance of...

  11. CSIR National Laser Centre develops a high speed OCT system

    CSIR Research Space (South Africa)

    Sharma, Ameeth

    2016-11-01

    Full Text Available . The system, which is not limited to this application, can image a large volume (25mm x 25mm x 11mm) and resultant 3-D images (512 x 512 x 2048 pixels) are acquired in less than three seconds. The heart of the system is a swept laser source and a two...

  12. High resolution Fresnel zone plate laser alignment system

    International Nuclear Information System (INIS)

    Bressler, V.E.; Fischer, G.E.; Ruland, R.E.; Wang, T.

    1992-03-01

    The existing Fresnel zone plate laser alignment system is currently being extended and upgraded for the Final Focus Test Beam (FFTB). Previously, the resolution of this system has been several tens of micrometers. After the upgrade, the resolution will be a few micrometers. Details of the upgrade as well as simulation and experimental results will be presented

  13. Performance of a MOPA laser system for photocathode research

    NARCIS (Netherlands)

    Mols, R.F.X.A.M.; Mols, R.F.X.A.M.; Ernst, G.J.

    1994-01-01

    A Nd:YLF laser system with frequency doubled output is described. Several aspects concerning energy and stability of the pulses will be discussed. The system consists of a CW mode locked Nd:YLF oscillator and two double pass amplifiers having a total small signal gain of about a million which means

  14. Aspirin inhibition of platelet deposition at angioplasty sites: demonstration by platelet scintigraphy

    International Nuclear Information System (INIS)

    Cuningham, D.A.; Kumar, B.; Siegel, B.A.; Gilula, L.A.; Totty, W.G.; Welch, M.J.

    1984-01-01

    In-111 platelet scintigraphy was used to evaluate the effects of prior aspirin administration on the accumulation of In-111-labeled autologous platelets at sites of arterial injury resulting from iliac, femoral, or popliteal transluminal angioplasty in a nonrandomized study of 17 men. The degree of platelet localization at angioplasty sites was significantly less in nine men who had received aspirin in varying doses within the 4 days before angioplasty than in eight men who had not received aspirin for at least two weeks. The results suggest that aspirin treatment before angioplasty limits the early platelet deposition at the angioplasty site in men

  15. Laser metrology and optic active control system for GAIA

    Science.gov (United States)

    D'Angelo, F.; Bonino, L.; Cesare, S.; Castorina, G.; Mottini, S.; Bertinetto, F.; Bisi, M.; Canuto, E.; Musso, F.

    2017-11-01

    The Laser Metrology and Optic Active Control (LM&OAC) program has been carried out under ESA contract with the purpose to design and validate a laser metrology system and an actuation mechanism to monitor and control at microarcsec level the stability of the Basic Angle (angle between the lines of sight of the two telescopes) of GAIA satellite. As part of the program, a breadboard (including some EQM elements) of the laser metrology and control system has been built and submitted to functional, performance and environmental tests. In the followings we describe the mission requirements, the system architecture, the breadboard design, and finally the performed validation tests. Conclusion and appraisals from this experience are also reported.

  16. Relay telescope for high power laser alignment system

    Science.gov (United States)

    Dane, C. Brent; Hackel, Lloyd; Harris, Fritz B.

    2006-09-19

    A laser system includes an optical path having an intracavity relay telescope with a telescope focal point for imaging an output of the gain medium between an image location at or near the gain medium and an image location at or near an output coupler for the laser system. A kinematic mount is provided within a vacuum chamber, and adapted to secure beam baffles near the telescope focal point. An access port on the vacuum chamber is adapted for allowing insertion and removal of the beam baffles. A first baffle formed using an alignment pinhole aperture is used during alignment of the laser system. A second tapered baffle replaces the alignment aperture during operation and acts as a far-field baffle in which off angle beams strike the baffle a grazing angle of incidence, reducing fluence levels at the impact areas.

  17. The laser-based calibration system of delta spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Malakhov, A.I. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Anisimov, Yu.S. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Gmuca, S. [Inst. of Physics, SAS, Bratislava (Slovakia); Kizka, V.A. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Kliman, J. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Inst. of Physics, SAS, Bratislava (Slovakia); Krasnov, V.A. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Kurepin, A.B. [Inst. for Nuclear Research RAS, Moscow (Russian Federation); Kuznetsov, S.N. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Livanov, A.N. [Veksler and Baldin Laboratory of High Energies, JINR, Dubna (Russian Federation); Matousek, V. [Inst. of Physics, SAS, Bratislava (Slovakia); Morhac, M. [Inst. of Physics, SAS, Bratislava (Slovakia)]. E-mail: Miroslav.Morhac@savba.sk; Turzo, I. [Inst. of Physics, SAS, Bratislava (Slovakia)

    2006-10-15

    We present a report on a laser calibration system of DELTA spectrometer that has been designed and developed in the Laboratory of High Energies, JINR, Dubna. The system is intended for monitoring and continuous stabilization of the outputs of the detectors of the spectrometer. The UV nitrogen pulse laser along with optical filters, collection of optical fibers and plastic scintillators serving for conversion of UV light pulses to longer wavelength and for diffusion of the light beam to illuminate 300 photomultipliers are used. We stabilize the positions of laser peaks by corrections of high voltages of the corresponding photomultipliers. The proposed system allows one to accomplish the stabilization during the experiment with the use of the same electronics. The control software together with the first results from test runs are described as well.

  18. Picosecond high power laser systems and picosecond diagnostic technique in laser produced plasma

    International Nuclear Information System (INIS)

    Kuroda, Hiroto; Masuko, H.; Maekawa, Shigeru; Suzuki, Yoshiji; Sugiyama, Masaru.

    1979-01-01

    Highly repetitive, high power YAG and Glass laser systems have been developed and been successfully used for the studies of laser-plasma interactions. Various picosecond diagnostic techniques have been developed for such purposes in the regions from optical to X-ray frequency. Recently highly sensitive X-ray (1 - 10 KeV) streak camera for highly repetitive operations have been developed. Preliminary experiment shows the achievement of 28ps temporal resolution (100μm slit) and good sensitivity with detectable minimum number of 10E3-1KeV photons/shot/slit area. (author)

  19. Help system for control of JAERI FEL (Free Electron laser)

    International Nuclear Information System (INIS)

    Sugimoto, Masayoshi

    1993-01-01

    The control system of JAERI FEL (Free Electron Laser) has a help system to provide the information necessary to operate the machine and to develop the new user interface. As the control software is constructed on the MS-Windows 3.x, the hyper-text feature of the Windows help system can be accessed. It consists of three major parts: (1) on-line help, (2) full document, and (3) tutorial system. (author)

  20. An All-Solid-State High Repetiton Rate Titanium:Sapphire Laser System For Resonance Ionization Laser Ion Sources

    Science.gov (United States)

    Mattolat, C.; Rothe, S.; Schwellnus, F.; Gottwald, T.; Raeder, S.; Wendt, K.

    2009-03-01

    On-line production facilities for radioactive isotopes nowadays heavily rely on resonance ionization laser ion sources due to their demonstrated unsurpassed efficiency and elemental selectivity. Powerful high repetition rate tunable pulsed dye or Ti:sapphire lasers can be used for this purpose. To counteract limitations of short pulse pump lasers, as needed for dye laser pumping, i.e. copper vapor lasers, which include high maintenance and nevertheless often only imperfect reliability, an all-solid-state Nd:YAG pumped Ti:sapphire laser system has been constructed. This could complement or even replace dye laser systems, eliminating their disadvantages but on the other hand introduce shortcomings on the side of the available wavelength range. Pros and cons of these developments will be discussed.

  1. Laser Soldering of Rat Skin Using a Controlled Feedback System

    Directory of Open Access Journals (Sweden)

    Mohammad Sadegh Nourbakhsh

    2009-03-01

    Full Text Available Introduction: Laser tissue soldering using albumin and indocyanine green dye (ICG is an effective technique utilized in various surgical procedures. The purpose of this study was to perform laser soldering of rat skin under a feedback control system and compare the results with those obtained using standard sutures. Material and Methods: Skin incisions were made over eight rats’ dorsa, which were subsequently closed using different wound closure interventions in two groups: (a using a temperature controlled infrared detector or (b by suture. Tensile strengths were measured at 2, 5, 7 and 10 days post-incision. Histological examination was performed at the time of sacrifice. Results: Tensile strength results showed that during the initial days following the incisions, the tensile strengths of the sutured samples were greater than the laser samples. However, 10 days after the incisions, the tensile strengths of the laser soldered incisions were higher than the sutured cuts. Histopathological examination showed a preferred wound healing response in the soldered skin compared with the control samples. The healing indices of the laser soldered repairs (426 were significantly better than the control samples (340.5. Conclusion: Tissue feedback control of temperature and optical changes in laser soldering of skin leads to a higher tensile strength and better histological results and hence this method may be considered as an alternative to standard suturing.

  2. Iterative Decoding for an Optical CDMA based Laser communication System

    International Nuclear Information System (INIS)

    Kim, Jin Young; Kim, Eun Cheol; Cha, Jae Sang

    2008-01-01

    An optical CDMA(code division multiple access)based Laser communication system has attracted much attention since it requires minimal optical Laser signal processing and it is virtually delay free, while from the theoretical point of view, its performance depends on the auto and cross correlation properties of employed sequences. Various kinds of channel coding schemes for optical CDMA based Laser communication systems have been proposed and analyzed to compensate nonideal channel and receiver conditions in impaired photon channels. In this paper, we propose and analyze an iterative decoding of optical CDMA based Laser communication signals for both shot noise limited and thermal noise limited systems. It is assumed that optical channel is an intensity modulated (IM)channel and direct detection scheme is employed to detect the received optical signal. The performance is evaluated in terms of bit error probability and throughput. It is demonstrated that the BER and throughput performance is substantially improved with interleaver length for a fixed code rate and with alphabet size of PPM (pulse position modulation). Also, the BER and throughput performance is significantly enhanced with the number of iterations for decoding process. The results in this paper can be applied to the optical CDMA based Laser communication network with multiple access applications

  3. Iterative Decoding for an Optical CDMA based Laser communication System

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Young; Kim, Eun Cheol [Kwangwoon Univ., Seoul (Korea, Republic of); Cha, Jae Sang [Seoul National Univ. of Technology, Seoul (Korea, Republic of)

    2008-11-15

    An optical CDMA(code division multiple access)based Laser communication system has attracted much attention since it requires minimal optical Laser signal processing and it is virtually delay free, while from the theoretical point of view, its performance depends on the auto and cross correlation properties of employed sequences. Various kinds of channel coding schemes for optical CDMA based Laser communication systems have been proposed and analyzed to compensate nonideal channel and receiver conditions in impaired photon channels. In this paper, we propose and analyze an iterative decoding of optical CDMA based Laser communication signals for both shot noise limited and thermal noise limited systems. It is assumed that optical channel is an intensity modulated (IM)channel and direct detection scheme is employed to detect the received optical signal. The performance is evaluated in terms of bit error probability and throughput. It is demonstrated that the BER and throughput performance is substantially improved with interleaver length for a fixed code rate and with alphabet size of PPM (pulse position modulation). Also, the BER and throughput performance is significantly enhanced with the number of iterations for decoding process. The results in this paper can be applied to the optical CDMA based Laser communication network with multiple access applications.

  4. Study and design on USB wireless laser communication system

    Science.gov (United States)

    Wang, Aihua; Zheng, Jiansheng; Ai, Yong

    2004-04-01

    We give the definition of USB wireless laser communication system (WLCS) and the brief introduction to the protocol of USB, the standard of hardware is also given. The paper analyses the hardware and software of USB WLCS. Wireless laser communication part and USB interface circuit part are discussed in detail. We also give the periphery design of the chip AN2131Q, the control circuit to realize the transformation from parallel port to serial bus, and the circuit of laser sending and receiving of laser communication part, which are simply, cheap and workable. And then the four part of software are analyzed as followed. We have consummated the ISR in the firmware frame to develop the periphery device of USB. We have debugged and consummated the 'ezload,' and the GPD of the drivers. Windows application performs functions and schedules the corresponding API functions to let the interface practical and beautiful. The system can realize USB wireless laser communication between computers, which distance is farther than 50 meters, and top speed can be bigger than 8 Mbps. The system is of great practical sense to resolve the issues of high-speed communication among increasing districts without fiber trunk network.

  5. Study and Development of a Laser Based Alignment System

    CERN Multimedia

    Stern, G

    2014-01-01

    CLIC (Compact Linear Collider) has tight requirements regarding pre-alignment of beam related components: 10 µm accuracy over a sliding window of 200 m along the 20 km of linac. To perform such an alignment, a new system is proposed combining laser beam as straight line reference and camera/shutter assemblies as sensors. The poster describes the alignment system and shows results regarding laser pointing stability with respect to time, shutter type, distance and environment. These results give a frame for future building and calibrating of sensors.

  6. Morphological differences in coronary arteries following rotational atherectomy versus balloon angioplasty: ultrasound and angioscopic observations

    Science.gov (United States)

    Bass, Theodore A.; Gilmore, Paul S.; White, Christopher J.; Chami, Youssef G.; Kircher, Barbara J.; Conetta, Donald A.

    1993-09-01

    Percutaneous transluminal coronary rotational atherectomy (PTCRA) is an exciting new device to recannulate obstructed coronary arteries. This device works as a high speed `drill,' selectively cutting hard atherosclerotic plaque while preferentially sparing the softer, less diseased vascular luminal surface. At speeds as high as 200,000 rpm the plaque is pulverized into small particles easily handled by the circulatory system with no untoward clinical sequela. Balloon angioplasty does not remove atherosclerotic plaque. It dilates the vessel by mechanically stretching, compressing and splitting the plaque and vessel lining. We compare morphological and surface luminal characteristics of vessels post PTCRA to vessels post PTCA.

  7. Subintimal angioplasty: predictors of long-term success.

    LENUS (Irish Health Repository)

    Keeling, Aoife N

    2009-08-01

    To determine the clinical outcomes and success rates after percutaneous subintimal angioplasty (SIA) in patients with lower-limb occlusive lesions causing intermittent claudication (IC) or critical limb ischemia (CLI) at midterm to long-term follow-up. The secondary aim was to elicit factors predictive of a successful outcome.

  8. Direct venous thrombolysis and venous angioplasty in the upper extremity

    International Nuclear Information System (INIS)

    Hollmann, J.P.; Guenther, R.W.

    1987-01-01

    Venous thromboses of stenoses in the upper extremity are often the result of a compression syndrome of the shoulder girdle, the Paget-von Schroetter syndrome, vascular surgery, space-occupying lesions in the mediastinum or the result of catheterisation. Direct venous thrombolysis and venous angioplasty were performed successfully in six patients. (orig.) [de

  9. Segmentally enclosed thrombolysis in percutaneous transluminal angioplasty for femoropopliteal occlusions

    DEFF Research Database (Denmark)

    Jørgensen, B; Tønnesen, K H; Nielsen, J D

    1991-01-01

    Segmentally enclosed thrombolysis (SET) was performed immediately following 34 percutaneous transluminal angioplasties (PTAs) for femoropopliteal occlusions. The dilated segment was sealed off with a double balloon catheter, and recombinant tissue plasminogen activator (rt-PA) 1 mg/ml and heparin...

  10. 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.

  11. Laser cleaner development for decontamination of the primary water cooling system at nuclear power plants

    International Nuclear Information System (INIS)

    Minehara, Eisuke

    2010-01-01

    We recently have performed the feasibility studies to develop laser cleaners utilizing several laser oscillator and amplifier systems like femto-second free-electron lasers, water-jet guided lasers, Q-switched YAG lasers, fiber lasers. Whenever we used to clean the RI-contaminated surface using the lasers, we should focus enough laser power in the surface to evaporate instantly without melting. Therefore, as the contaminated being deeply located into the surface could be removed using any one set of the lasers, we found that every trial of laser cleaning could remove very well the RI contamination being located deeply. Our cold decontamination test using a model sample being Cobalt plated successfully has been performed to show a very high decontamination factor. In order to develop an usable laser cleaner, we plan to develop the prototype laser cleaner next year. (author)

  12. Beam transport optics for high-power laser systems

    International Nuclear Information System (INIS)

    Taylor, J.R.

    1995-01-01

    Beam transport optics receive output energy from the laser cavity and deliver it to the work site. Depending on the application, this may require a few simple elements or large complex systems. Collection of the laser energy depends on the spatial and temporal energy distribution as well as the wavelength and polarization of the laser cavity and output coupler. Transport optics can perform a variety of functions, including beam formatting, frequency doubling, and distribution to one or more work sites while maintaining or even improving the beam quality. The beam may be delivered to work sites as focused spots or images, projected to distant targets, or propagated through various media for sensing or photochemical processing. Design may involve optical modeling of the system, including diffraction effects and thermal management. A Gaussian beam profile is often used for convenience in modeling. When deviations from this ideal profile need to be considered, it is necessary to characterize the laser beam in detail. Design of the transport system requires understanding of the interaction of the laser energy with optical materials and components. Practical considerations include mounting the optics without stress and with the stability suitable for the intended application. Requirements for beam direction, stability, size, shape, and quality dictate the design approach for each specific situation. Attention also must be given to reliability, environmental, and commercial requirements. Damage to optics in high-power laser systems is a common concern. Environmental problems such as atmospheric turbulence, contamination by dust or vapor from the work site or other sources, or absorption of water vapor can directly degrade beam quality. Other potentially significant optical performance effects may result from instability and aging of the optics, temperature, humidity, pressure, transmitted vibration, and contamination from the work site or other sources

  13. Remote Fiber Laser Cutting System for Dismantling Glass Melter - 13071

    Energy Technology Data Exchange (ETDEWEB)

    Mitsui, Takashi; Miura, Noriaki [IHI Corporation, 1 Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa (Japan); Oowaki, Katsura; Kawaguchi, Isao [IHI Inspection and Instrumentation Co., Ltd, 1 Shin-Nakahara-cho, Isogo-ku, Yokohama, Kanagawa (Japan); Miura, Yasuhiko; Ino, Tooru [Japan Nuclear Fuel Limited, 4-108, Aza Okitsuke, Oaza Obuchi, Rokkasho-Mura, Kamikita-gun, Aomori (Japan)

    2013-07-01

    Since 2008, the equipment for dismantling the used glass melter has been developed in High-level Liquid Waste (HLW) Vitrification Facility in the Japanese Rokkasho Reprocessing Plant (RRP). Due to the high radioactivity of the glass melter, the equipment requires a fully-remote operation in the vitrification cell. The remote fiber laser cutting system was adopted as one of the major pieces of equipment. An output power of fiber laser is typically higher than other types of laser and so can provide high-cutting performance. The fiber laser can cut thick stainless steel and Inconel, which are parts of the glass melter such as casings, electrodes and nozzles. As a result, it can make the whole of the dismantling work efficiently done for a shorter period. Various conditions of the cutting test have been evaluated in the process of developing the remote fiber cutting system. In addition, the expected remote operations of the power manipulator with the laser torch have been fully verified and optimized using 3D simulations. (authors)

  14. Free-space QKD system hacking by wavelength control using an external laser.

    Science.gov (United States)

    Lee, Min Soo; Woo, Min Ki; Jung, Jisung; Kim, Yong-Su; Han, Sang-Wook; Moon, Sung

    2017-05-15

    We develop a way to hack free-space quantum key distribution (QKD) systems by changing the wavelength of the quantum signal laser using an external laser. Most free-space QKD systems use four distinct lasers for each polarization, thereby making the characteristics of each laser indistinguishable. We also discover a side-channel that can distinguish the lasers by using an external laser. Our hacking scheme identifies the lasers by automatically applying the external laser to each signal laser at different intensities and detecting the wavelength variation according to the amount of incident external laser power. We conduct a proof-of-principle experiment to verify the proposed hacking structure and confirm that the wavelength varies by several gigahertzes to several nanometers, depending on the intensity of the external laser. The risk of hacking is successfully proven through the experimental results. Methods for prevention are also suggested.

  15. Data acquisition system for fusion diagnostics on the ARGUS laser

    International Nuclear Information System (INIS)

    Greenwood, J.R.; Campbell, D.E.; Frerking, C.E.

    1976-09-01

    An extensive data acquisition and analysis system has been implemented for experiments on the ARGUS laser. The system is based upon a PDP-11/40 minicomputer and CAMAC interfaces. Highspeed transient digitizers, calorimeter digitizing modules and time integrated data are interfaced through CAMAC over a fiber optic serial highway. The system allows for dynamic definition of the experimental environment by an operator, automatic data acquisition during a shot. Two interactive graphics terminals allow experimenters real-time access to target shot data

  16. A high-power laser system for thermonuclear fusion experiments

    International Nuclear Information System (INIS)

    Azizov, Eh.A.; Ignat'ev, L.P.; Koval'skij, N.G.; Kolesnikov, Yu.A.; Mamzer, A.F.; Pergament, M.I.; Rudnitskij, Yu.P.; Smirnov, G.V.; Yagnov, V.A.; Nikolaevskij, V.G.

    1976-01-01

    A high-power laser system has been designed for an energy output of approximately 3X10 4 J. Neodymium glass was selected based on the level of technical progress, operating experience and the availability of components. The operating performance that has been achieved to date is described. (author)

  17. Evolution of Spark plasma using nitrogen laser shadowgraphy system

    International Nuclear Information System (INIS)

    Ishiekwene, G.C.

    1994-07-01

    A simple, low cost, home built high power nitrogen laser is used as the light source for a shadowgraphy system. A series of shadowgrams depicting the temporal growth of a spark plasma discharge is obtained. The results could be useful in plasma diagnostic studies. (author). 5 refs, 6 figs

  18. Multifunction laser systems in clinical and resort practice

    OpenAIRE

    Zabulonov, Yuriy; Vladimirov, Alexander; Chukhraiev, Nikolay; Elmehsenawi, Yousry; Zukow, Walery

    2016-01-01

    SHUPYKNATIONALMEDICALACADEMY OF POSTGRADUATE EDUCATION UKRAINIANSOCIETY OFPHYSICAL AND REHABILITATION MEDICINE RADOM UNIVERSITY Yuriy Zabulonov, Alexander Vladimirov, Nikolay Chukhraiev, Yousry Elmehsenawi, Walery Zukow MULTIFUNCTION LASER SYSTEMS IN CLINICAL AND RESORT PRACTICE Edited by Yuriy Zabulonov, Alexander Vladimirov, Nikolay Chukhraiev, Yousry Elmehsenawi, Walery Zukow ...

  19. Laser system for identification, tracking, and control of flying insects

    Science.gov (United States)

    Flying insects are common vectors for transmission of pathogens and inflict significant harm on humans in large parts of the developing world. Besides the direct impact to humans, these pathogens also cause harm to crops and result in agricultural losses. Here, we present a laser-based system that c...

  20. Benchmarking Advanced Control Algorithms for a Laser Scanner System

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Ordys, A.W.; Smillie, I.

    1996-01-01

    The paper describes tests performed on the laser scanner system toassess feasibility of modern control techniques in achieving a requiredperformance in the trajectory following problem. The two methods tested areQTR H-infinity and Predictive Control. The results are ilustated ona simulation example....

  1. Laser Guided Automated Calibrating System for Accurate Bracket ...

    African Journals Online (AJOL)

    Background: The basic premise of preadjusted bracket system is accurate bracket positioning. ... using MATLAB ver. 7 software (The MathWorks Inc.). These images are in the form of matrices of size 640 × 480. 650 nm (red light) type III diode laser is used as ... motion control and Pitch, Yaw, Roll degrees of freedom (DOF).

  2. Petawatt laser and target irradiation system at LLNL

    International Nuclear Information System (INIS)

    Pennington, D.M.; Perry, M.D.; Britten, J.A.; Brown, C.G.; Herman, S.; Homer, J.; Miller, J.L.; Stuart, B.C.; Tietbohl, G.; Van Lue, J.; Yanovsky, V.

    1997-01-01

    In May, 1996, we demonstrated the production over a petawatt of peak power in the Nova/Petawatt Laser Facility, generating 620 J in ∼ 430 fs. Results of the first focused irradiance tests, and recent deployment of a novel targeting system will be presented

  3. The exposure of radiologists and patients to radiation during coronary angiography and percutaneous transluminal coronary angioplasty (PTCA)

    International Nuclear Information System (INIS)

    Karppinen, J.; Parviainen, T.

    1993-03-01

    The exposure of radiologists and patients to radiation during coronary angiography and percutaneous transluminal coronary angioplasty (PTCA) in Finland was studied using phantom measurements. Additional tests were made concerning the performance of TV fluoroscopy systems, cine fluorographic units and film processing. These tests include sensitometric quality control of film processing, automatic exposure control in fluoroscopy and cinefluorography, and contrast and resolution in a cine frame and TV image

  4. CW Yb:YAG LASER FOR PORTABLE MEASURING SYSTEMS

    Directory of Open Access Journals (Sweden)

    A. M. Ivashko

    2014-01-01

    Full Text Available The theoretical and experimental results of longitudinally continuous-wave diode-pumped Yb:Y3Al5O12 (YAG laser performance for compact field-condition measuring systems were demonstrated. Optimization of laser setup in terms of operation condition in the range of -40 ˚С – +65 ˚С without active thermal stabilization was carried out. Using Yb (10 ат.%:YAG crystal with the length of 3 mm the maximal output power more than 2 W was obtained in the whole of temperature range.

  5. Femtosecond Synchronization of Laser Systems for the LCLS

    International Nuclear Information System (INIS)

    Byrd, John; Doolittle, Lawrence; Huang, Gang; Staples, John; Wilcox, Russell; Arthur, John; Frisch, Josef; White, William

    2012-01-01

    The scientific potential of femtosecond x-ray pulses at linac-driven free-electron lasers such as the Linac Coherent Light Source is tremendous. Time-resolved pump-probe experiments require a measure of the relative arrival time of each x-ray pulse with respect to the experimental pump laser. An optical timing system based on stabilized fiber links has been developed for the LCLS to provide this synchronization. Preliminary results show synchronization of the installed stabilized links at the sub-20-femtosecond level. We present details of the implementation at LCLS and potential for future development.

  6. Z-Beamlet: a multikilojoule, terawatt-class laser system

    International Nuclear Information System (INIS)

    Rambo, Patrick K.; Smith, Ian C.; Porter, John L. Jr.; Hurst, Michael J.; Speas, C. Shane; Adams, Richard G.; Garcia, Antonio J.; Dawson, Ellis; Thurston, Benjamin D.; Wakefield, Colleen; Kellogg, Jeff W.; Slattery, Michael J.; Ives III, Harry C.; Broyles, Robin S.; Caird, John A.; Erlandson, Alvin C.; Murray, James E.; Behrendt, William C.; Neilsen, Norman D.; Narduzzi, Joseph M.

    2005-01-01

    A large-aperture (30-cm) kilojoule-class Nd:glass laser system known as Z-Beamlet has been constructed to perform x-ray radiography of high-energy-density science experiments conducted on the Z facility at Sandia National Laboratories, Albuquerque, New Mexico. The laser, operating with typical pulse durations from 0.3 to 1.5 ns, employs a sequence of successively larger multipass amplifiers to achieve up to 3-kJ energy at 1054 nm. Large-aperture frequency conversion and long-distance beam transport can provide on-target energies of up to 1.5 kJ at 527 nm

  7. Design of High Precise Focusing System in Laser Direct Writer

    International Nuclear Information System (INIS)

    Liang, Y Y; Tian, F; Luo, J B; Yang, G G

    2006-01-01

    In order to improve the accuracy and efficiency of fabricating lines with laser pattern generator, a novel focusing system was designed. Focusing system is based on optical off-axis detection principle. The detector is a two-quadrant photocell and the defocus signal is constructed by division. Focusing system has the character of second-order system with overdamp. The new embedded PID controller improves the performance of focusing system and upgrades the closed-loop precision to 0.2 μm. Furthermore focusing system has the fabrication capabilities for alterable-width lines under various defocus amount

  8. Cost-effectiveness analysis of orbital atherectomy plus balloon angioplasty vs balloon angioplasty alone in subjects with calcified femoropopliteal lesions

    Science.gov (United States)

    Weinstock, Barry; Dattilo, Raymond; Diage, Tiffini

    2014-01-01

    Introduction As cost considerations become increasingly critical when selecting optimal endovascular treatment strategies, a cost-benefit analysis was conducted comparing the Diamondback 360°® Orbital Atherectomy System (OAS) (Cardiovascular Systems, Inc., St Paul, MN, USA) and balloon angioplasty (BA) vs BA alone for treatment of calcified femoropopliteal lesions. Patients and methods The clinical outcomes from COMPLIANCE 360°, a prospective, multicenter, randomized study comparing OAS+BA vs BA alone for treatment of calcified femoropopliteal lesions, were correlated with cost data and previously published quality of life data. Site of service, hospital charges, and associated medical resource utilization were obtained from Uniform Billing statements for index treatments and associated revascularizations out to 1 year. Hospital costs were estimated using hospital-specific, procedure-specific cost-to-charge ratios. Length of stay and procedural data were collected from participating study sites. Results Twenty-five subjects with 38 lesions and 25 subjects with 27 lesions were randomized to the OAS+BA and BA-alone groups, respectively. Mean hospital charges (US$51,755 vs US$39,922) and estimated hospital costs (US$15,100 vs US$11,016) were higher for OAS+BA compared with BA alone (not statistically significant). Stent utilization was statistically significantly higher with BA-alone treatment for all subjects (1.1 vs 0.1, P=0.001) and in the subset of subjects with one lesion (1.0 vs 0.1, Patherectomy for treatment of calcified femoropopliteal lesions, a longstanding challenge for peripheral artery disease interventionalists. PMID:24672251

  9. The study on laser photochemical process of Diazonaphthoquinon-Cresol system

    International Nuclear Information System (INIS)

    Wei Jie; Huang Yu Li; Wang Wenke

    1999-01-01

    The kinetic process of laser photochemical reaction of diazonaphthoquinon-cresol system was studied by using laser spectrophotofluorimetry and laser induced fluorescence attenuation method. The nonlinear relationship between photodecomposition rate of the sensitizer and laser power, exposure time and concentration of solutions was discussed in detail

  10. Activity of respiratory system during laser irradiation of brain structures

    Science.gov (United States)

    Merkulova, N. A.; Sergeyeva, L. I.

    1984-06-01

    The performance of one of the principal links of the respiratory system, the respiratory center, was studied as a function of the exposure of the medulla oblongata and the sensomotor zone of the cerebral hemisphere cortex to low level laser irradiation in the red wavelength of the spectrum. Experiments were done on white rats under barbital anesthesia. Under such conditions a substantial effect was observed on the activity of the respiratory center. Laser light may display activating or inhibitory influences, in some cases the bilateral symmetry of the activity of the respiratory center is affected indicating deep changes in the integrative mechanism of the functioning of the right and left sides of the hemispheres. The laser beam effect depends on many factors: specific light properties, duration of the exposure, repetition of exposures, initial functional state of the CNS, etc.

  11. Beam propagation considerations in the Aurora laser system

    International Nuclear Information System (INIS)

    Rosoche, L.A.; Mc Leod, J.; Hanlon, J.A.

    1987-01-01

    Aurora is a high-power KrF laser system now being constructed for inertial confinement fusion (ICF) studies. It will use optical angular multiplexing and serial amplification by electron-beam-driven KrF amplifiers to deliver a stacked, multikilojoule 5-ns-duration laser pulse to ICF targets. The requirements of angular multiplexing KrF lasers at the multikilojoule level dictate path lengths on the order of 1 km. The inherent complicated path crossings produced by angular multiplexing and pulse stacking do not allow isolation of individual beam lines, so the optical quality of the long beam paths must be controlled. Propagation of the 248-nm light beams over long paths in air is affected by scattering, absorption thermal gradients and turbulence, beam alignment, and control and optical component figure errors

  12. A description of the apparatus to be used in interaction experiments with the ABC laser system

    International Nuclear Information System (INIS)

    Caruso, A.; Strangio, M.; Andreoli, P.L.; Cerioni, I.; Di Paolo, A.; Di Virgilio, L.

    1988-01-01

    This report contains the part of the Frascati Laboratorio Fusione Laser activity related to the Apparatus (target chamber, position and alignement system, diagnostics) to be used in the interaction experiments with the ABC laser system

  13. Design of remote laser-induced fluorescence system's acquisition circuit

    Science.gov (United States)

    Wang, Guoqing; Lou, Yue; Wang, Ran; Yan, Debao; Li, Xin; Zhao, Xin; Chen, Dong; Zhao, Qi

    2017-10-01

    Laser-induced fluorescence system(LIfS) has been found its significant application in identifying one kind of substance from another by its properties even it's thimbleful, and becomes useful in plenty of fields. Many superior works have reported LIfS' theoretical analysis , designs and uses. However, the usual LIPS is always constructed in labs to detect matter quite closely, for the system using low-power laser as excitation source and charge coupled device (CCD) as detector. Promoting the detectivity of LIfS is of much concern to spread its application. Here, we take a high-energy narrow-pulse laser instead of commonly used continuous wave laser to operate sample, thus we can get strong fluorescent. Besides, photomultiplier (PMT) with high sensitivity is adopted in our system to detect extremely weak fluorescence after a long flight time from the sample to the detector. Another advantage in our system, as the fluorescence collected into spectroscopy, multiple wavelengths of light can be converted to the corresponding electrical signals with the linear array multichannel PMT. Therefore, at the cost of high-powered incentive and high-sensitive detector, a remote LIFS is get. In order to run this system, it is of importance to turn light signal to digital signal which can be processed by computer. The pulse width of fluorescence is deeply associated with excitation laser, at the nanosecond(ns) level, which has a high demand for acquisition circuit. We design an acquisition circuit including, I/V conversion circuit, amplifying circuit and peak-holding circuit. The simulation of circuit shows that peak-holding circuit can be one effective approach to reducing difficulty of acquisition circuit.

  14. Laser system for testing radiation imaging detector circuits

    Science.gov (United States)

    Zubrzycka, Weronika; Kasinski, Krzysztof

    2015-09-01

    Performance and functionality of radiation imaging detector circuits in charge and position measurement systems need to meet tight requirements. It is therefore necessary to thoroughly test sensors as well as read-out electronics. The major disadvantages of using radioactive sources or particle beams for testing are high financial expenses and limited accessibility. As an alternative short pulses of well-focused laser beam are often used for preliminary tests. There are number of laser-based devices available on the market, but very often their applicability in this field is limited. This paper describes concept, design and validation of laser system for testing silicon sensor based radiation imaging detector circuits. The emphasis is put on keeping overall costs low while achieving all required goals: mobility, flexible parameters, remote control and possibility of carrying out automated tests. The main part of the developed device is an optical pick-up unit (OPU) used in optical disc drives. The hardware includes FPGA-controlled circuits for laser positioning in 2 dimensions (horizontal and vertical), precision timing (frequency and number) and amplitude (diode current) of short ns-scale (3.2 ns) light pulses. The system is controlled via USB interface by a dedicated LabVIEW-based application enabling full manual or semi-automated test procedures.

  15. Performance of a high repetition pulse rate laser system for in-gas-jet laser ionization studies with the Leuven laser ion source LISOL

    International Nuclear Information System (INIS)

    Ferrer, R.; Sonnenschein, V.T.; Bastin, B.; Franchoo, S.; Huyse, M.; Kudryavtsev, Yu.; Kron, T.; Lecesne, N.; Moore, I.D.; Osmond, B.; Pauwels, D.; Radulov, D.; Raeder, S.; Rens, L.

    2012-01-01

    The laser ionization efficiency of the Leuven gas cell-based laser ion source was investigated under on- and off-line conditions using two distinctly different laser setups: a low-repetition rate dye laser system and a high-repetition rate Ti:sapphire laser system. A systematic study of the ion signal dependence on repetition rate and laser pulse energy was performed in off-line tests using stable cobalt and copper isotopes. These studies also included in-gas-jet laser spectroscopy measurements on the hyperfine structure of 63 Cu. A final run under on-line conditions in which the radioactive isotope 59 Cu (T 1/2 = 81.5 s) was produced, showed a comparable yield of the two laser systems for in-gas-cell ionization. However, a significantly improved time overlap by using the high-repetition rate laser system for in-gas-jet ionization was demonstrated by an increase of the overall duty cycle, and at the same time, pointed to the need for a better shaped atomic jet to reach higher ionization efficiencies.

  16. Land-Based Mobile Laser Scanning Systems: a Review

    Science.gov (United States)

    Puente, I.; González-Jorge, H.; Arias, P.; Armesto, J.

    2011-09-01

    Mobile mapping has been using various photogrammetric techniques for many years. In recent years, there has been an increase in the number of mobile mapping systems using laser scanners available in the market, partially because of the improvement in GNSS/INS performance for direct georeferencing. In this article, some of the most important land-based mobile laser scanning (MLS) systems are reviewed. Firstly, the main characteristics of MLS systems vs. airborne (ALS) and terrestrial laser scanning (TLS) systems are compared. Secondly, a short overview of the mobile mapping technology is also provided so that the reader can fully grasp the complexity and operation of these devices. As we put forward in this paper, a comparison of different systems is briefly carried out regarding specifications provided by the manufacturers. Focuses on the current research are also addressed with emphasis on the practical applications of these systems. Most of them have been utilized for data collection on road infrastructures or building façades. This article shows that MLS technology is nowadays well established and proven, since the demand has grown to the point that there are several systems suppliers offering their products to satisfy this particular market.

  17. Modeling of photoluminescence in laser-based lighting systems

    Science.gov (United States)

    Chatzizyrli, Elisavet; Tinne, Nadine; Lachmayer, Roland; Neumann, Jörg; Kracht, Dietmar

    2017-12-01

    The development of laser-based lighting systems has been the latest step towards a revolution in illumination technology brought about by solid-state lighting. Laser-activated remote phosphor systems produce white light sources with significantly higher luminance than LEDs. The weak point of such systems is often considered to be the conversion element. The high-intensity exciting laser beam in combination with the limited thermal conductivity of ceramic phosphor materials leads to thermal quenching, the phenomenon in which the emission efficiency decreases as temperature rises. For this reason, the aim of the presented study is the modeling of remote phosphor systems in order to investigate their thermal limitations and to calculate the parameters for optimizing the efficiency of such systems. The common approach to simulate remote phosphor systems utilizes a combination of different tools such as ray tracing algorithms and wave optics tools for describing the incident and converted light, whereas the modeling of the conversion process itself, i.e. photoluminescence, in most cases is circumvented by using the absorption and emission spectra of the phosphor material. In this study, we describe the processes involved in luminescence quantum-mechanically using the single-configurational-coordinate diagram as well as the Franck-Condon principle and propose a simulation model that incorporates the temperature dependence of these processes. Following an increasing awareness of climate change and environmental issues, the development of ecologically friendly lighting systems featuring low power consumption and high luminous efficiency is imperative more than ever. The better understanding of laser-based lighting systems is an important step towards that aim as they may improve on LEDs in the near future.

  18. Alignment system for SGII-Up laser facility

    Science.gov (United States)

    Gao, Yanqi; Cui, Yong; Li, Hong; Gong, Lei; Lin, Qiang; Liu, Daizhong; Zhu, Baoqiang; Ma, Weixin; Zhu, Jian; Lin, Zunqi

    2018-03-01

    The SGII-Up laser facility in Shanghai is one of the most important high-power laser facilities in China. It is designed to obtain 24 kJ (3ω) of energy with a square pulse of 3 ns using eight laser beams (two bundles). To satisfy the requirements for the safety, efficiency, and quality, an alignment system is developed for this facility. This alignment system can perform automatic alignment of the preamplifier system, main amplifier system, and harmonic conversion system within 30 min before every shot during the routine operation of the facility. In this article, an overview of the alignment system is first presented. Then, its alignment characteristics are discussed, along with the alignment process. Finally, experimental results, including the alignment results and the facility performance, are reported. The results show that the far-field beam pointing alignment accuracy is better than 3 μrad, and the alignment error of the near-field beam centering is no larger than 1 mm. These satisfy the design requirements very well.

  19. Laser fusion power reactor system (LFPRS)

    International Nuclear Information System (INIS)

    Kovacik, W.P.

    1977-01-01

    This report gives detailed information for each of the following areas: (1) reference concept description, (2) nuclear design, (3) structural design, (4) thermal and fluid systems design, (5) materials design and analysis, (6) reactor support systems and balance of plant, (7) instrumentation and control, (8) environment and safety, (9) economics assessment, and (10) development requirements

  20. Control system for high power laser drilling workover and completion unit

    Science.gov (United States)

    Zediker, Mark S; Makki, Siamak; Faircloth, Brian O; DeWitt, Ronald A; Allen, Erik C; Underwood, Lance D

    2015-05-12

    A control and monitoring system controls and monitors a high power laser system for performing high power laser operations. The control and monitoring system is configured to perform high power laser operation on, and in, remote and difficult to access locations.

  1. Directivity measurements in aluminum using a laser ultrasonics system

    International Nuclear Information System (INIS)

    Sakamoto, J M S; Pacheco, G M; Tittmann, B R; Baba, A

    2011-01-01

    A laser ultrasonics system was setup to measure the directivity (angular dependence pattern) of the amplitude of ultrasonic waves generated in aluminum samples. A pulsed Nd:YAG laser operating at 1064 nm optical wavelength, with typical pulse width (FWHM) of 8 ns, and energy per pulse of 450 mJ, was used to generate the ultrasound waves in the samples. The laser detection system was a Mach-Zehnder interferometer with typical noise-limited resolution of 0.25 nm (rms), frequency range from 50 kHz to 20 MHz, and measurement range from -75 nm/V to +75 nm/V. Two different optical spot sizes of the Nd:YAG laser were used to generate waves in the ablation regime: one was focused and the other was unfocused. Using the obtained data, the directivity graphics were drawn and compared with the theoretical curves, showing a good agreement. The experiments showed the directivity as a function of the optical spot size. For a point ultrasonic source (or focused optical spot), the directivity shows that the longitudinal waves present considerable amplitude in all directions. For a larger ultrasonic source (or an unfocused optical spot) the directivity shows that the longitudinal waves are generated with the higher amplitudes inside angles around ±10 0 .

  2. The Laser Calibration System of the ALICE Time Projection Chamber

    CERN Document Server

    Renault, G; Nielsen, B S; Westergaard, J

    2005-01-01

    A Large Ion Collider Experiment (ALICE) is the only experiment at the Large Hadron Collider (LHC) dedicated to the study of heavy ion collisions. The Time Projection Chamber (TPC) is the main tracking detector covering the pseudo rapidity range $|\\eta|< 0.9$. It is designed for a maximum multiplicity \\dNdy = 8000. The aim of the laser system is to simulate ionizing tracks at predifined positions throughout the drift volume in order to monitor the TPC response to a known source. In particular, the alignment of the read-out chambers will be performed, and variations of the drift velocity due to drift field imperfections can be measured and used as calibration data in the physics data analysis. In this paper we present the design of the pulsed UV laser and optical system, together with the control and monitoring systems.

  3. System and Method for Generating a Frequency Modulated Linear Laser Waveform

    Science.gov (United States)

    Pierrottet, Diego F. (Inventor); Petway, Larry B. (Inventor); Amzajerdian, Farzin (Inventor); Barnes, Bruce W. (Inventor); Lockard, George E. (Inventor); Hines, Glenn D. (Inventor)

    2017-01-01

    A system for generating a frequency modulated linear laser waveform includes a single frequency laser generator to produce a laser output signal. An electro-optical modulator modulates the frequency of the laser output signal to define a linear triangular waveform. An optical circulator passes the linear triangular waveform to a band-pass optical filter to filter out harmonic frequencies created in the waveform during modulation of the laser output signal, to define a pure filtered modulated waveform having a very narrow bandwidth. The optical circulator receives the pure filtered modulated laser waveform and transmits the modulated laser waveform to a target.

  4. Components for monolithic fiber chirped pulse amplification laser systems

    Science.gov (United States)

    Swan, Michael Craig

    The first portion of this work develops techniques for generating femtosecond-pulses from conventional fabry-perot laser diodes using nonlinear-spectral-broadening techniques in Yb-doped positive dispersion fiber ampliers. The approach employed an injection-locked fabry-perot laser diode followed by two stages of nonlinear-spectral-broadening to generate sub-200fs pulses. This thesis demonstrated that a 60ps gain-switched fabry-perot laser-diode can be injection-locked to generate a single-longitudinal-mode pulse and compressed by nonlinear spectral broadening to 4ps. Two problems have been identified that must be resolved before moving forward with this approach. First, gain-switched pulses from a standard diode-laser have a number of characteristics not well suited for producing clean self-phase-modulation-broadened pulses, such as an asymmetric temporal shape, which has a long pulse tail. Second, though parabolic pulse formation occurs for any arbitrary temporal input pulse profile, deviation from the optimum parabolic input results in extensively spectrally modulated self-phase-modulation-broadened pulses. In conclusion, the approach of generating self-phase-modulation-broadened pulses from pulsed laser diodes has to be modified from the initial approach explored in this thesis. The first Yb-doped chirally-coupled-core ber based systems are demonstrated and characterized in the second portion of this work. Robust single-mode performance independent of excitation or any other external mode management techniques have been demonstrated in Yb-doped chirally-coupled-core fibers. Gain and power efficiency characteristics are not compromised in any way in this novel fiber structure up to the 87W maximum power achieved. Both the small signal gain at 1064nm of 30.3dB, and the wavelength dependence of the small signal gain were comparable to currently deployed large-mode-area-fiber technology. The efficiencies of the laser and amplifier were measured to be 75% and 54

  5. Charged-particle acceleration through laser irradiation of thin foils at Prague Asterix Laser System

    International Nuclear Information System (INIS)

    Torrisi, Lorenzo; Cutroneo, Maria; Cavallaro, Salvatore; Musumeci, Paolo; Calcagno, Lucia; Wolowski, Jerzy; Rosinski, Marcin; Zaras-Szydlowska, Agnieszka; Ullschmied, Jiri; Krousky, Eduard; Pfeifer, Miroslav; Skala, Jiri; Velyhan, Andreiy

    2014-01-01

    Thin foils, 0.5–50 μm in thickness, have been irradiated in vacuum at Prague Asterix Laser System in Prague using 10 15–16  W cm −2 laser intensity, 1315 nm wavelength, 300 ps pulse duration and different focal positions. Produced plasmas from metals and polymers films have been monitored in the forward and backward directions. Ion and electron accelerations have been investigated by using Thomson parabola spectrometer, x-ray streak camera, ion collectors and SiC semiconductor detectors, the latter employed in time-of-flight configuration. Ion acceleration up to about 3 MeV per charge state was measured in the forward direction. Ion and electron emissions were detected at different angles as a function of the irradiation conditions. (paper)

  6. Nova laser assurance-management system

    International Nuclear Information System (INIS)

    Levy, A.J.

    1983-01-01

    In a well managed project, Quality Assurance is an integral part of the management activities performed on a daily basis. Management assures successful performance within budget and on schedule by using all the good business, scientific, engineering, quality assurance, and safety practices available. Quality assurance and safety practices employed on Nova are put in perspective by integrating them into the overall function of good project management. The Nova assurance management system was developed using the quality assurance (QA) approach first implemented at LLNL in early 1978. The LLNL QA program is described as an introduction to the Nova assurance management system. The Nova system is described pictorially through the Nova configuration, subsystems and major components, interjecting the QA techniques which are being pragmatically used to assure the successful completion of the project

  7. Critical appraisal of paclitaxel balloon angioplasty for femoral-popliteal arterial disease.

    Science.gov (United States)

    Herten, Monika; Torsello, Giovanni B; Schönefeld, Eva; Stahlhoff, Stefan

    2016-01-01

    Peripheral arterial disease, particularly critical limb ischemia, is an area with urgent need for optimized therapies because, to date, vascular interventions often have limited life spans. In spite of initial encouraging technical success after femoropopliteal percutaneous transluminal angioplasty or stenting, postprocedural restenosis remains the major problem. The challenging idea behind the drug-coated balloon (DCB) concept is the biological modification of the injury response after balloon dilatation. Antiproliferative drugs administered via DCBs or drug-eluting stents are able to suppress neointimal hyperplasia, the main cause of restenosis. This article reviews the results of DCB treatments of femoropopliteal and infrapopliteal lesions in comparison to standard angioplasty with uncoated balloons. A systematic literature search was performed in 1) medical journals (ie, MEDLINE), 2) international registers for clinical studies (ie, www.clinicaltrials.gov), and 3) abstracts of scientific sessions. Several controlled randomized trials with follow-up periods of up to 5 years demonstrated the efficacy of paclitaxel -DCB technology. However, calcified lesions seem to affect the efficacy of DCB. Combinations of preconditioning methods with DCBs showed promising results. Although the mechanical abrasion of calcium via atherectomy or laser ablation showed favorable periprocedural results, the long-term impact on restenosis and clinical outcome has to be demonstrated. Major advantages of the DCBs are the rapid delivery of drug at uniform concentrations with a single dose, their efficacy in areas wherein stents have been contraindicated until now (ie, bifurcation, ostial lesions), and in leaving no stent scaffold behind. Reinterventions are easier to perform because DCBs leave no metal behind. Various combinations of DCBs with other treatment modalities may prove to be viable options in future. The follow-up results of clinical studies will evaluate the long-term impact

  8. Laser Demonstration and Performance Characterization of an Optically Pumped Alkali Laser System

    Science.gov (United States)

    2010-09-01

    ground state 2S1/2 on the D1 line. An example of this is shown in Figure 1 from Krupke’s original paper for the rubidium transitions. In addition to...any of the alkali’s listed in Table 1 can be used in a three-level laser system to create a DPAL system. However, for practical applications...Figure 39, the pump energy per pulse is 3 mJ, providing a pump intensity of ≅ 2 x 106 W/cm2, much higher than the saturation intensity of Isat = (hν

  9. Dosimetry of beta emitting radionuclides for use in balloon angioplasty

    International Nuclear Information System (INIS)

    Fox, R.A.

    1997-01-01

    The dose at varying distances from the surface of an infinite cylinder containing 90 Y, 32 P and 188 Re respectively is calculated using published scaled point dose kernels for these three radionuclides. It is shown that all are suitable radionuclides for use in the irradiation of arteries subsequent to balloon angioplasty. All three may be used as a radioactive liquid in the angioplasty balloon, thereby simplifying the procedure and enabling a uniform radiation dose to be given to the arterial wall. It is however shown that there is a rapid reduction in dose with distance from the arterial wall which demands careful specification of the prescribed radiation dose. A similar rapid reduction with distance is also found with a central radioactive wire or with a radioactive stent containing the same radionuclides. (author)

  10. A Rare and Serious Unforeseen Complication of Cutting Balloon Angioplasty

    Directory of Open Access Journals (Sweden)

    Praveen Vemula

    2014-01-01

    Full Text Available Cutting balloon angioplasty (CBA is one of the adept ways of treating “in-stent restenosis.” Various complications related to cutting balloon angioplasty have been reported including arterial rupture, delayed perforation and fracture of microsurgical blades. Here we report a very unusual and inadvertent extraction of a stent previously deployed in the ramus intermedius coronary branch by a cutting balloon catheter. This required repeat stenting of the same site for an underlying dissection. Even though stent extraction is a rare complication it can be serious due to dissection, perforation, and closure of the artery. Physicians performing coronary artery interventions would need to be aware of this rare and serious complication especially if any difficulty is encountered while withdrawing the cutting balloon. Therefore, after removal, cutting balloon should be examined thoroughly for possible stent dislodgment or extraction when used for “in-stent restenosis.”

  11. Fibre laser based broadband THz imaging systems

    DEFF Research Database (Denmark)

    Eichhorn, Finn

    imaging techniques. This thesis exhibits that fiber technology can improve the robustness and the flexibility of terahertz imaging systems both by the use of fiber-optic light sources and the employment of optical fibers as light distribution medium. The main focus is placed on multi-element terahertz...

  12. Laser system for measuring small changes in plasma tracer concentrations.

    Science.gov (United States)

    Klaesner, J W; Pou, N A; Parker, R E; Galloway, R L; Roselli, R J

    1996-01-01

    The authors developed a laser-diode system that can be used for on-line optical concentration measurements in physiologic systems. Previous optical systems applied to whole blood have been hampered by artifacts introduced by red blood cells (RBCs). The system introduced here uses a commercially available filter cartridge to separate RBCs from plasma before plasma concentration measurements are made at a single wavelength. The filtering characteristics of the Cellco filter cartridge (#4007-10, German-town, MD) were adequate for use in the on-line measurement system. The response time of the filter cartridge was less than 40 seconds, and the sieving characteristics of the filter for macromolecules were excellent, with filtrate-to-plasma albumin ratios of 0.98 +/- 0.11 for studies in sheep and 0.94 +/- 0.15 for studies in dogs. The 635-nm laser diode system developed was shown to be more sensitive than the spectrophotometer used in previous studies (Klaesner et al., Annals of Biomedical Engineering, 1994; 22, 660-73). The new system was used to measure the product of filtration coefficient (Kfc) and reflection coefficient for albumin (delta f) in an isolated canine lung preparation. The delta fKfc values [mL/(cmH2O.min.100 g dry lung weight)] measured with the laser diode system (0.33 +/- 0.22) compared favorably with the delta fKfc obtained using a spectrophotometer (0.27 +/- 0.20) and with the Kfc obtained using the blood-corrected gravimetric method (0.32 +/- 0.23). Thus, this new optical system was shown to accurately measure plasma concentration changes in whole blood for physiologic levels of Kfc. The same system can be used with different optical tracers and different source wavelengths to make optical plasma concentration measurements for other physiologic applications.

  13. Enabling vendor independent photoacoustic imaging systems with asynchronous laser source

    Science.gov (United States)

    Wu, Yixuan; Zhang, Haichong K.; Boctor, Emad M.

    2018-02-01

    Channel data acquisition, and synchronization between laser excitation and PA signal acquisition, are two fundamental hardware requirements for photoacoustic (PA) imaging. Unfortunately, however, neither is equipped by most clinical ultrasound scanners. Therefore, less economical specialized research platforms are used in general, which hinders a smooth clinical transition of PA imaging. In previous studies, we have proposed an algorithm to achieve PA imaging using ultrasound post-beamformed (USPB) RF data instead of channel data. This work focuses on enabling clinical ultrasound scanners to implement PA imaging, without requiring synchronization between the laser excitation and PA signal acquisition. Laser synchronization is inherently consisted of two aspects: frequency and phase information. We synchronize without communicating the laser and the ultrasound scanner by investigating USPB images of a point-target phantom in two steps. First, frequency information is estimated by solving a nonlinear optimization problem, under the assumption that the segmented wave-front can only be beamformed into a single spot when synchronization is achieved. Second, after making frequencies of two systems identical, phase delay is estimated by optimizing the image quality while varying phase value. The proposed method is validated through simulation, by manually adding both frequency and phase errors, then applying the proposed algorithm to correct errors and reconstruct PA images. Compared with the ground truth, simulation results indicate that the remaining errors in frequency correction and phase correction are 0.28% and 2.34%, respectively, which affirm the potential of overcoming hardware barriers on PA imaging through software solution.

  14. Aberrations and focusability in large solid-state-laser systems

    International Nuclear Information System (INIS)

    Simmons, W.W.

    1981-01-01

    Solid state lasers for fusion experiments must reliably deliver maximum power to small (approximately .5 mm) targets from stand-off focal distances of 1 m or more. This requirement places stringent limits upon the optical quality of the several major components - amplifiers, Faraday isolators, spatial filters - in each amplifier train. Residual static aberrations in optical components are transferred to the beam as it traverses the optical amplifier chain. Although individual components are typically less than lambda/20 for components less than 10 cm clear aperture; and less than lambda/10 for components less than 20 cm clear aperture; the large number of such components in optical series results in a wavefront error that may exceed one wave for modern solid state lasers. For pulse operation, the focal spot is additionally broadened by intensity dependent nonlinearities. Specific examples of the performance of large aperture components will be presented within the context of the Argus and Shiva laser systems, which are presently operational at Lawrence Livermore National Laboratory. Design requirements upon the larger aperture Nova laser components, up to 74 cm in clear aperture, will also be discussed; these pose a significant challenge to the optical industry

  15. Intensity position modulation for free-space laser communication system

    Science.gov (United States)

    Jangjoo, Alireza; Faghihi, F.

    2004-12-01

    In this research a novel modulation technique for free-space laser communication system called Intensity Position Modulation (IPM) is carried out. According to TEM00 mode of a laser beam and by linear fitting on the Gaussian function as an approximation, the variation of linear part on the reverse biased pn photodiode produced alternating currents which contain the information. Here, no characteristic property of the beam as intensity or frequency is changed and only the beam position moves laterally. We demonstrated that in this method no bandwidth is required, so it is possible to reduce the background radiation noise by narrowband filtering of the carrier. The fidelity of the analog voice communication system which is made upon the IPM is satisfactory and we are able to transmit the audio signals up to 1Km.

  16. Lifetime of chaotic attractors in a multidimensional laser system

    International Nuclear Information System (INIS)

    Pando L, C.L.; Cerdeira, H.A.

    1995-01-01

    We study the lifetimes of chaotic attractors at crises in a multidimensional laser system. This system describes the CO 2 laser with modulated losses and is known as the four-level model. The critical exponents which are related to the lifetimes of the attractors are estimated in terms of the corresponding eigenvalues and the measured characteristic lifetime in the model. The critical exponents in this model and those of its center manifold version are in good agreement. We conjecture that generically in the four-level model the critical exponents are close to 1/2 at crises. In addition, we compare predictions of a simpler and popular model known as the two-level model with those of the above mentioned models. (author). 21 refs, 2 figs, 3 tabs

  17. Transluminal coronary angioplasty in the treatment of silent ischemia

    International Nuclear Information System (INIS)

    Bergin, P.; Myler, R.K.; Shaw, R.E.; Stertzer, S.H.; Clark, D.A.; Ryan, C.; Murphy, M.C.

    1988-01-01

    Fifty-four asymptomatic patients with positive thallium exercise tests underwent coronary angiography followed by coronary angioplasty (PTCA), as the primary therapy for silent ischemia. The procedure was technically successful in 89% of these patients. Emergency bypass graft surgery was necessary in 2 (3.6%) and q-wave myocardial infarction occurred in 1 (1.8%) of these. All fifty-four patients have been followed for a mean of 35 months since angioplasty. Of the 48 patients with initially successful PTCA, 12 had either clinical restenosis (9/14 or 19%) or a new lesion (3/48 or 6%) during follow-up, which required a repeat PTCA. At the longest follow-up, 46 (85%) had been successfully treated with on or more PTCA procedures. Two patients (3.6%) had sustained late q-wave myocardial infarction and two additional patients reported angina pectoris. There were no deaths. Angioplasty as a primary therapy for silent ischemia appears efficacious, with success and restenosis rates comparable to those in the symptomatic population. Event-free survival is improved, compared with natural history data for patients with silent ischemia from other studies. Prudent risk/benefit analysis may help to define subgroups most likely to benefit from this intervention

  18. [Surgical angioplasty of the left main coronary artery].

    Science.gov (United States)

    Vranes, Mile; Velinović, Milos; Kocica, Mladen; Mikić, Aleksandar; Velimirović, Dusan; Djukić, Petar

    2010-01-01

    The conventional treatment for isolated stenosis of the left main coronary artery is bypass surgery (myocardial revascularization). However, the process of atherosclerosis is not arrested by myocardial revascularization and it will lead to the occlusion of the left main coronary artery. Revascularization will establish retrograde perfusion for 50-70% of the myocardium of the left ventricle. Direct surgical angioplasty of the left main coronary artery enables normal physiological perfusion of the whole myocardium and better myocardial function. The aim of our study is to point out a new surgical approach of treating left main coronary artery stenosis. Between October 2002 and October 2003, direct surgical angioplasty of the main left coronary artery was performed on three patients with isolated stenosis of the left main coronary artery using the anterior approach and the pericardium as a patch. The procedure was performed under total endotracheal anaesthesia and standard cardiopulmonary circulation, moderate hypothermia, anterograde St. Tomas cardioplegia and local cooling. Patients were followed clinically, echocardiographically and by load-tests. All three patients were without complications. In postoperative follow-up (54-68 months) neither angina pectoris nor electrocardiographically registered ischaemic changes were found. Load-tests performed every six months on all three patients were negative. Surgical angioplasty of isolated stenosis of the left main coronary artery is a preferred method for treating this type of coronary disease. Contraindications for this type of treatment are stenosis of the left main coronary artery with bifurcation and advanced calcification of the left main coronary artery.

  19. Below knee angioplasty in elderly patients: Predictors of major adverse clinical outcomes.

    LENUS (Irish Health Repository)

    Keeling, Aoife N

    2011-03-01

    To determine predictors of clinical outcome following percutaneous transluminal angioplasty (PTA) in elderly patients with below knee atherosclerotic lesions causing intermittent claudication (IC) or critical limb ischaemia (CLI).

  20. Usefulness of cutting balloon angioplasty for the treatment of congenital heart defects.

    Science.gov (United States)

    Kusa, Jacek; Mazurak, Magdalena; Skierska, Agnieszka; Szydlowski, Leslaw; Czesniewicz, Pawel; Manka, Lukasz

    2018-01-01

    Patients with complex congenital heart defects may have different hemodynamic prob-lems which require a variety of interventional procedures including angioplasty which involves using high-pressure balloons. After failure of conventional balloon angioplasty, cutting balloon angioplasty is the next treatment option available. The purpose of this study was to evaluate the safety and efficacy of cutting balloon angioplasty in children with different types of congenital heart defects. Cutting balloon angioplasty was performed in 28 children with different congenital heart defects. The indication for cutting balloon angioplasty was: pulmonary artery stenosis in 17 patients, creating or dilatation of interatrial communication in 10 patients, and stenosis of left subclavian artery in 1 patient. In the pulmonary arteries group there was a significant decrease in systolic blood pressure (SBP) in the proximal part of the artery from the average 74.33 ± 20.4 mm Hg to 55 ± 16.7 mm Hg (p cutting balloon angioplasty was performed after an unsuccessful classic Rashkind procedure. After cutting balloon angioplasty there was a significant widening of the interatrial communication. Cutting balloon angioplasty is a feasible and effective treatment option in different con-genital heart defects.

  1. The development of the intelligent diagnostic expert system for high power dye-laser MOPA system

    International Nuclear Information System (INIS)

    Liu Lianhua; Yang Wenxi; Zhang Xiaowei; Dan Yongjun

    2014-01-01

    A intelligent diagnostic expert system was required to simulate the expert thinking process of solving problem in experiment and to real-time judge the running state of the experiment system. The intelligent diagnostic expert system for dye-laser MOPA system was build with the modular design of separated knowledge base and inference engine, the RETE algorithm rules match, the asynchronous operation, and multithreading technology. The experiment result indicated that the system could real-time analysis and diagnose the running state of dye-laser MOPA system with advantages of high diagnosis efficiency, good instantaneity and strong expansibility. (authors)

  2. The evolution of the laser: A systems perspective on science, technology and society

    Science.gov (United States)

    Deruiter, Willem

    The evolution of laser technology is addressed, and an attempt is made to correlate this evolution to the macrosociological theory of Juergen Habermas. The economic and social consequences of innovations are evaluated. Different laser applications are described. The evolution of the semiconductor laser is discussed. The evolution of optical telecommunication systems is outlined. The Habermas theory of communicative action, focussing on the theoretical distinction between 'system' and 'lifeworld,' is treated. The modified theory of Habermas is applied to the evolution of the laser. The embedding of a number of laser applications in the social context is discussed: laser isotope separation, compact disc players, and the Strategic Defense Initiative.

  3. Research on calibration algorithm in laser scanning projection system

    Science.gov (United States)

    Li, Li Juan; Qu, Song; Hou, Mao Sheng

    2017-10-01

    Laser scanning projection technology can project the image defined by the existing CAD digital model to the working surface, in the form of a laser harness profile. This projection is in accordance with the ratio of 1: 1. Through the laser harness contours with high positioning quality, the technical staff can carry out the operation with high precision. In a typical process of the projection, in order to determine the relative positional relationship between the laser projection instrument and the target, it is necessary to place several fixed reference points on the projection target and perform the calibration of projection. This position relationship is the transformation from projection coordinate system to the global coordinate system. The entire projection work is divided into two steps: the first step, the calculation of the projector six position parameters is performed, that is, the projector calibration. In the second step, the deflection angle is calculated by the known projector position parameter and the known coordinate points, and then the actual model is projected. Typically, the calibration requires the establishment of six reference points to reduce the possibility of divergence of the nonlinear equations, but the whole solution is very complex and the solution may still diverge. In this paper, the distance is detected combined with the calculation so that the position parameters of the projector can be solved by using the coordinate values of three reference points and the distance of at least one reference point to the projector. The addition of the distance measurement increases the stability of the solution of the nonlinear system and avoids the problem of divergence of the solution caused by the reference point which is directly under the projector. Through the actual analysis and calculation, the Taylor expansion method combined with the least squares method is used to obtain the solution of the system. Finally, the simulation experiment is

  4. Shipborne Laser Beam Weapon System for Defence against Cruise Missiles

    OpenAIRE

    J.P. Dudeja; G.S. Kalsey

    2000-01-01

    Sea-skim~ing cruise missiles pose the greatest threat to a surface ship in the present-day war scenario. The convenitional close-in-weapon-systems (CIWSs) are becoming less reliable against these new challenges requiring extremely fast reaction time. Naval Forces see a high energy laser as a feasible andjeffective directed energy weapon against sea-skimming antiship cruise missiles becauseof its .ability to deliver destructive energy at the speed of light on to a distant target. The paper com...

  5. Qualification and issues with space flight laser systems and components

    Science.gov (United States)

    Ott, Melanie N.; Coyle, D. B.; Canham, John S.; Leidecker, Henning W., Jr.

    2006-02-01

    The art of flight quality solid-state laser development is still relatively young, and much is still unknown regarding the best procedures, components, and packaging required for achieving the maximum possible lifetime and reliability when deployed in the harsh space environment. One of the most important issues is the limited and unstable supply of quality, high power diode arrays with significant technological heritage and market lifetime. Since Spectra Diode Labs Inc. ended their involvement in the pulsed array business in the late 1990's, there has been a flurry of activity from other manufacturers, but little effort focused on flight quality production. This forces NASA, inevitably, to examine the use of commercial parts to enable space flight laser designs. System-level issues such as power cycling, operational derating, duty cycle, and contamination risks to other laser components are some of the more significant unknown, if unquantifiable, parameters that directly effect transmitter reliability. Designs and processes can be formulated for the system and the components (including thorough modeling) to mitigate risk based on the known failures modes as well as lessons learned that GSFC has collected over the past ten years of space flight operation of lasers. In addition, knowledge of the potential failure modes related to the system and the components themselves can allow the qualification testing to be done in an efficient yet, effective manner. Careful test plan development coupled with physics of failure knowledge will enable cost effect qualification of commercial technology. Presented here will be lessons learned from space flight experience, brief synopsis of known potential failure modes, mitigation techniques, and options for testing from the system level to the component level.

  6. Bond strength of an adhesive system irradiated with Nd:YAG laser in dentin treated with Er:YAG laser

    International Nuclear Information System (INIS)

    Malta, D A M P; De Andrade, M F; Costa, M M; Lizarelli, R F Z; Pelino, J E P

    2008-01-01

    The purpose of this in vitro study was to verify through micro tensile bond test the bond strength of an adhesive system irradiated with Nd:YAG laser in dentine previously treated with Er:YAG laser. Twenty caries free extracted human third molars were used. The teeth were divided in four experimental groups (n = 5): (G1) control group; (G2) irradiation of the adhesive system with the Nd:YAG laser; (G3) dentin treatment with Er:YAG laser; (G4) dentin treatment with Er:YAG laser followed by the irradiation of the adhesive system with Nd:YAG laser. The Er:YAG laser fluency parameter for the dentin treatment was of 60 J/cm 2 . The adhesive system was irradiated with the Nd:YAG laser with fluency of 100 J/cm 2 . Dental restorations were performed with Adper Single Bond 2/Z250. One tooth from each group was prepared for the evaluation of the adhesive interface under SEM and bond failure tests were also performed and evaluated. The statistical analysis showed statistical significant difference between the groups G1 and G3, G1 and G4, G2 and G3, and G2 and G4; and similarity between the groups G1 and G2, and G3 and G4. The adhesive failures were predominant in all the experimental groups. The SEM analysis showed an adhesive interface with features confirming the results of the mechanical tests. The Nd:YAG laser on the adhesive system did not influence the bond strength in dentin treated or not with the Er:YAG laser

  7. Development of laser weld monitoring system for PWR space grid

    International Nuclear Information System (INIS)

    Chung, Chin Man; Kim, Cheol Jung; Kim, Min Suk

    1998-06-01

    The laser welding monitoring system was developed to inspect PWR space grid welding for KNFC. The demands for this optical monitoring system were applied to Q.C. and process control in space grid welding. The thermal radiation signal from weld pool can be get the variation of weld pool size. The weld pool size and depth are verified by analyzed wavelength signals from weld pool. Applied this monitoring system in space grid weld, improved the weld productivity. (author). 4 refs., 5 tabs., 31 figs

  8. A Ship Cargo Hold Inspection Approach Using Laser Vision Systems

    OpenAIRE

    SHEN Yang; ZHAO Ning; LIU Haiwei; MI Chao

    2013-01-01

    Our paper represents a vision system based on the laser measurement system (LMS) for bulk ship inspection. The LMS scanner with 2-axis servo system is installed on the ship loader to build the shape of the ship. Then, a group of real-time image processing algorithms are implemented to compute the shape of the cargo hold, the inclination angle of the ship and the relative position between the ship loader and the cargo hold. Based on those computed inspection data of the ship, the ship loader c...

  9. Study on load temperature control system of ground laser communication

    Science.gov (United States)

    Zhai, Xunhua; Zhang, Hongtao; Liu, Wangsheng; Zhang, Chijun; Zhou, Xun

    2007-12-01

    The ground laser communication terminal as the termination of a communication system, works at the temperature which varies from -40°C to 50°C. We design a temperature control system to keep optical and electronic components working properly in the load. The load is divided into two sections to control temperature respectively. Because the space is limited, we use heater film and thermoelectric cooler to clearify and refrigerate the load. We design a hardware and a software for the temperature control system, establish mathematic model, and emulate it with Matlab.

  10. Alignment and focusing device for a multibeam laser system

    International Nuclear Information System (INIS)

    Sweatt, W.C.

    1980-01-01

    Large inertial confinement fusion laser systems have many beams focusing on a small target. The Antares system is a 24-beam CO 2 pulse laser. To produce uniform illumination, the 24 beams must be individually focused on (or near) the target's surface in a symmetric pattern. To assess the quality of a given beam, we will locate a Smartt (point diffraction) interferometer at the desired focal point and illuminate it with an alignment laser. The resulting fringe pattern shows defocus, lateral misalignment, and beam aberrations; all of which can be minimized by tilting and translating the focusing mirror and the preceding flat mirror. The device described in this paper will remotely translate the Smartt interferometer to any position in the target space and point it in any direction using a two-axis gimbal. The fringes produced by the interferometer are relayed out of the target vacuum shell to a vidicon by a train or prisms. We are designing four separate snap-in heads to mount on the gimbal; two of which are Smartt interferometers (for 10.6 μm and 633 nm) and two for pinholes, should we wish to put an alignment beam backwards through the system

  11. Advanced wavefront measurement and analysis of laser system modeling

    Energy Technology Data Exchange (ETDEWEB)

    Wolfe, C.R.; Auerback, J.M. [Lawrence Livermore National Lab., CA (United States)

    1994-11-15

    High spatial resolution measurements of the reflected or transmitted wavefronts of large aperture optical components used in high peak power laser systems is now possible. These measurements are produced by phase shifting interferometry. The wavefront data is in the form of 3-D phase maps that reconstruct the wavefront shape. The emphasis of this work is on the characterization of wavefront features in the mid-spatial wavelength range (from 0.1 to 10.0 mm) and has been accomplished for the first time. Wavefront structure from optical components with spatial wavelengths in this range are of concern because their effects in high peak power laser systems. At high peak power, this phase modulation can convert to large magnitude intensity modulation by non-linear processes. This can lead to optical damage. We have developed software to input the measured phase map data into beam propagation codes in order to model this conversion process. We are analyzing this data to: (1) Characterize the wavefront structure produced by current optical components, (2) Refine our understanding of laser system performance, (3) Develop a database from which future optical component specifications can be derived.

  12. Method and system for homogenizing diode laser pump arrays

    Science.gov (United States)

    Bayramian, Andy J

    2013-10-01

    An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance. A second intensity profile measured at the input face of the amplifier slab as a function of the first direction has a variation less than 10%.

  13. A 1J LD pumped Nd:YAG pulsed laser system

    Science.gov (United States)

    Yi, Xue-bin; Wang, Bin; Yang, Feng; Li, Jing; Liu, Ya-Ping; Li, Hui-Jun; Wang, Yu; Chen, Ren

    2017-11-01

    A 1J LD pumped Nd;YAG pulsed laser was designed. The laser uses an oscillation and two-staged amplification structure, and applies diode bar integrated array as side-pump. The TEC temperature control device combing liquid cooling system is organized to control the temperature of the laser system. This study also analyzed the theoretical threshold of working material, the effect of thermal lens and the basic principle of laser amplification. The results showed that the laser system can achieve 1J, 25Hz pulse laser output, and the laser pulse can be output at two width: 6-7ns and 10ns, respectively, and the original beam angle is 1.2mrad. The laser system is characterized by small size, light weight, as well as good stability, which make it being applied in varied fields such as photovoltaic radar platform and etc

  14. Double-shell target designs for the Los Alamos Scientific Laboratory eight-beam laser system

    International Nuclear Information System (INIS)

    Kindel, J.M.; Stroscio, M.A.

    1978-03-01

    We investigate two double-pusher laser fusion targets, one that incorporates an outer exploding pusher shell and another that uses velocity multiplication. Specific designs are presented for the Los Alamos Scientific Laboratory Eight-Beam Laser System

  15. Near-infrared laser, time domain, breast tumour detection system

    International Nuclear Information System (INIS)

    Joblin, A.J.

    1996-01-01

    Full text: The use of near-infrared laser, time domain techniques have been proposed for some time now as an alternative to X-ray mammography, as a means of mass screening for breast disease. The great driving force behind this research has been that near-infrared photons are a non-ionising radiation, which affords a greater degree of patient safety than when using X-rays. This would mean that women at risk of breast disease could be screened with a near-infrared laser imaging system, much more regularly than with an X-ray mammography system, which should allow for the earlier detection and treatment of breast disease. This paper presents a theoretical investigation of the performance of a near-infrared, time domain breast imaging system. The performance of the imaging system is characterised by the resolution and contrast parameters, which were studied using a numerical finite difference calculation method. The finite difference method is used to solve the diffusion equation for the photon transport through the inhomogeneous breast tissue medium. Optimal performance was found to be obtained with short photon times of flight. However the signal to noise ratio decreases rapidly as the photon time of flight is decreased. The system performance will therefore be limited by the noise equivalent power of the time resolved detection system, which is the signal incident on the time resolved detection system which gives a signal to noise ratio of 1:1. Photon times of flight shorter than 500 ps are not practical with current technology, which places limits on the resolution and contrast. The photon signal throughput can be increased by increasing the size of the laser beam width, by increasing the size of the aperture stop of the detector, by increasing the laser pulse duration or decreasing the detector time resolution. Best system performance is found by optimising these parameters for a given time gating and detector system characteristic (NEP). It was found that the

  16. Synchronization control for ultrafast laser parallel microdrilling system

    Science.gov (United States)

    Zhai, Zhongsheng; Kuang, Zheng; Ouyang, Jinlei; Liu, Dun; Perrie, Walter; Edwardson, Stuart P.; Dearden, Geoff

    2014-11-01

    Ultrafast lasers, emitting ultra-short pulses of light, generally of the order of femtoseconds to ten picoseconds, are widely used in micro-processing with the advantage of very little thermal damage. Parallel micro-processing is seen significant developments in laser fabrication, thanking to the spatial light modulator (SLM) which can concert single beam to multiple beams through computer generate holograms (CGHs). However, without synchronization control, on the conditions of changing different holograms or processing on large area beyond scanning galvo's ability, the fabrication will be interrupted constantly for changing holograms and moving the stages. Therefore, synchronization control is very important to improve the convenience and application of parallel micro-processing. A synchronization control method, carried out through two application software: SAMLight (or WaveRunner) and Labview, is presented in this paper. SAMLight is used to control the laser and the scanning galvo to implement microprocessing, and the developed program with Labview is used to control the SLM and motion stages. The synchronization signals, transmitted between the two software, are utilized by a National Instruments (NI) device USB-6008. Using optimal control methods, the synchronized system can easily and automatically accomplish complicated fabrications with minimum time. A multi-drilling application is provided to verify the affectivity of the synchronized control method. It uses multiple annular beams, generated by superimposing multi-beam CGH onto a diffractive axicon CGH, to drill multiple holes at one time, and it can automatically finish different patterns based on synchronization control. This drilling way is an optical trepanning and it avoids huge laser energy waste with attenuation. The multi-beam CGHs, generated by the Grating and Lens algorithm, are different for different patterns. The processing is over 200 times faster than traditional mechanical trepanning

  17. Airborne Laser Systems Testing and Analysis (essals et analyse des systemes laser embarques)

    Science.gov (United States)

    2010-04-01

    Pyroelectric Probe PG Proportional Guidance PILASTER PISQ LASer Test and Evaluation Range PIM Pixel Intensity Matrix PISQ Poligono Interforze del Salto di...requirements for upgrading the PISQ test/ training range ( Poligono Interforze del Salto di Quirra – Sardinia – Italy), adding new facilities for...INTRODUCTION This chapter describes the requirements for upgrading the PISQ ( Poligono Interforze del Salto di Quirra – Sardinia, Italy), adding new facilities

  18. Lasers

    CERN Document Server

    Milonni, Peter W

    1988-01-01

    A comprehensive introduction to the operating principles and applications of lasers. Explains basic principles, including the necessary elements of classical and quantum physics. Provides concise discussions of various laser types including gas, solid state, semiconductor, and free electron lasers, as well as of laser resonators, diffraction, optical coherence, and many applications including holography, phase conjugation, wave mixing, and nonlinear optics. Incorporates many intuitive explanations and practical examples. Discussions are self-contained in a consistent notation and in a style that should appeal to physicists, chemists, optical scientists and engineers.

  19. Initial evaluation of a femtosecond laser system in cataract surgery.

    Science.gov (United States)

    Chang, John S M; Chen, Ivan N; Chan, Wai-Man; Ng, Jack C M; Chan, Vincent K C; Law, Antony K P

    2014-01-01

    To report the early experience and complications during cataract surgery with a noncontact femtosecond laser system. Hong Kong Sanatorium and Hospital, Hong Kong Special Administrative Region, China. Retrospective case series. All patients had anterior capsulotomy or combined anterior capsulotomy and lens fragmentation using a noncontact femtosecond laser system (Lensar) before phacoemulsification. Chart and video reviews were performed retrospectively to determine the intraoperative complication rate. Risk factors associated with the complications were also analyzed. One hundred seventy eyes were included. Free-floating capsule buttons were found in 151 eyes (88.8%). No suction break occurred in any case. Radial anterior capsule tears occurred in 9 eyes (5.3%); they did not extend to the equator or posterior capsule. One eye (0.6%) had a posterior capsule tear. No capsular block syndrome developed, and no nuclei were dropped during irrigation/aspiration (I/A). Anterior capsule tags and miosis occurred in 4 eyes (2.4%) and 17 eyes (10.0%), respectively. Different severities of subconjunctival hemorrhages developed in 71 (43.8%) of 162 eyes after the laser procedure. The mean surgical time from the beginning to the end of suction was 6.72 minutes ± 4.57 (SD) (range 2 to 28 minutes). Cataract surgery with the noncontact femtosecond laser system was safe. No eye lost vision because of complications. Caution should be taken during phacoemulsification and I/A to avoid radial anterior capsule tears and posterior capsule tears. Copyright © 2013 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  20. Real Time Trajectory Correction System Of Optical Head In Laser Welding

    Directory of Open Access Journals (Sweden)

    Cieszyński Wojciech

    2015-12-01

    Full Text Available Application of laser welding technology requires that the laser beam is guided through the whole length of the joint with sufficiently high accuracy. This paper describes result of research on development of optomechatronic system that allows for the precise positioning of the laser head’s TCP point on the edge of welded elements during laser processing. The developed system allows for compensation of workpiece’s fixture inaccuracies, precast distortions and workpiece deformations occurring during the process.

  1. Development and application of an automatic system for measuring the laser camera

    International Nuclear Information System (INIS)

    Feng Shuli; Peng Mingchen; Li Kuncheng

    2004-01-01

    Objective: To provide an automatic system for measuring imaging quality of laser camera, and to make an automatic measurement and analysis system. Methods: On the special imaging workstation (SGI 540), the procedure was written by using Matlab language. An automatic measurement and analysis system of imaging quality for laser camera was developed and made according to the imaging quality measurement standard of laser camera of International Engineer Commission (IEC). The measurement system used the theories of digital signal processing, and was based on the characteristics of digital images, as well as put the automatic measurement and analysis of laser camera into practice by the affiliated sample pictures of the laser camera. Results: All the parameters of imaging quality of laser camera, including H-D and MTF curve, low and middle and high resolution of optical density, all kinds of geometry distort, maximum and minimum density, as well as the dynamic range of gray scale, could be measured by this system. The system was applied for measuring the laser cameras in 20 hospitals in Beijing. The measuring results showed that the system could provide objective and quantitative data, and could accurately evaluate the imaging quality of laser camera, as well as correct the results made by manual measurement based on the affiliated sample pictures of the laser camera. Conclusion: The automatic measuring system of laser camera is an effective and objective tool for testing the quality of the laser camera, and the system makes a foundation for the future research

  2. Detecting Topological Defect Dark Matter Using Coherent Laser Ranging System

    Science.gov (United States)

    Yang, Wanpeng; Leng, Jianxiao; Zhang, Shuangyou; Zhao, Jianye

    2016-01-01

    In the last few decades, optical frequency combs with high intensity, broad optical bandwidth, and directly traceable discrete wavelengths have triggered rapid developments in distance metrology. However, optical frequency combs to date have been limited to determine the absolute distance to an object (such as satellite missions). We propose a scheme for the detection of topological defect dark matter using a coherent laser ranging system composed of dual-combs and an optical clock via nongravitational signatures. The dark matter field, which comprises a defect, may interact with standard model particles, including quarks and photons, resulting in the alteration of their masses. Thus, a topological defect may function as a dielectric material with a distinctive frequency-depend index of refraction, which would cause the time delay of a periodic extraterrestrial or terrestrial light. When a topological defect passes through the Earth, the optical path of long-distance vacuum path is altered, this change in optical path can be detected through the coherent laser ranging system. Compared to continuous wavelength(cw) laser interferometry methods, dual-comb interferometry in our scheme excludes systematic misjudgement by measuring the absolute optical path length. PMID:27389642

  3. Gaseous saturable absorbers for the Helios CO2 laser system

    International Nuclear Information System (INIS)

    Haglund, R.F. Jr.; Nowak, A.V.; Czuchlewski, S.J.

    1981-01-01

    Saturable absorbers are widely used to suppress parasitic oscillations in large-aperture, high-power CO 2 fusion-laser systems. We report experimental results on SF 6 -based gaseous saturable absorbers used for parasitic suppression in the eight-beam, 10 kJ Helios fusion-laser system. The gas mix effectively quenches self-lasing in the 9 and 10 μm branches of the CO 2 laser spectrum while simultaneously allowing high transmission of subnanosecond multiwavelength pulses for target-irradiation experiments. The gas isolator now in use consists of SF 6 and the additional fluorocarbons: 1, 1-difluoroethane (FC-152a); dichlorodifluoromethane (FC-12); chloropentafluoroethane (FC-115); 1,1-dichloro 2,2-difluoroethylene (FC-1112a); chlorotrifluoroethylene (FC-1113); and perfluorocyclobutane (FC-C318). The saturation of the mix was studied as a function of incident fluence, pressure, cell length, and incident wavelength. Experimental results are presented on the saturation properties of pure SF 6 and FC-152a and compared with the saturation behavior of CO 2 at 400 0 C

  4. Laser application for nuclear reaction product detecting system alignment

    International Nuclear Information System (INIS)

    Grantsev, V.I.; Dryapachenko, I.P.; Kornilov, V.A.; Nemets, O.F.; Rudenko, B.A.; Sokolov, M.V.; Struzhko, B.G.; Gnatovskij, A.V.; Bojchuk, V.N.

    1982-01-01

    A method for optical alignment of nuclear particle detector system using a laser beam and hologram is described. The method permits to arrange detectors very precisely in accordance with any chosen space coordinate values. The results of modelling the geometry of an experiment based on using the suggested method on cyclotron beams are described. A gas helium-neon laser with wavelength of 0.63 μm radiation power of an order of 2 MW and angular beam divergence less than 10 angular minutes is used for modelling. It is concluded that the laser and hologram application provides large possibilities for the modelling the geometry of experiments on nuclear reaction investigation. When necessary it is possible to obtain small nonius scale of reference beams by means of multiplicating properties of the wave front modulator-hologram system. It is also possible to record holograms shaping the reference beams in two or several planes crossing along the central beam direction. Such holograms can be used for modelling the noncoplanar geometry of correlation experiments [ru

  5. An all-solid state laser system for the laser ion source RILIS and in-source laser spectroscopy of astatine at ISOLDE, CERN

    CERN Document Server

    Rothe, Sebastian; Nörtershäuser, W

    This doctoral thesis describes the extension of the resonance ionization laser ion source RILIS at ISOLDE, CERN, by the addition of an all-solid state tuneable titanium: sapphire (Ti:Sa) laser system to complement the well-established system of dye lasers. Synchronous operation of the so called Dual RILIS system of Ti:Sa and dye lasers was investigated and the potential for increased ion beam intensity, reliability, and reduced setup time has been demonstrated. In-source resonance ionization spectroscopy was performed at ISOLDE, CERN, and at ISAC, TRIUMF, radioactive ion beam facilities to develop an efficient and selective three-colour ionization scheme for the purely radioactive element astatine. A LabVIEW based monitoring, control and measurement system was conceived which enabled, in conjunction with Dual RILIS operation, the spectroscopy of high lying Rydberg states, from which the ionization potential of the astatine atom was determined for the first time experimentally.

  6. An all-solid state laser system for the laser ion sources RILIS and in-source laser spectroscopy of astatine at ISOLDE/CERN

    International Nuclear Information System (INIS)

    Rothe, Sebastian

    2012-01-01

    This doctoral thesis describes the extension of the resonance ionization laser ion source RILIS at CERN/ISOLDE by the addition of an all-solid state tunable titanium:sapphire (Ti:Sa) laser system to complement the well-established system of dye lasers. Synchronous operation of the so called Dual RILIS system of Ti:Sa and dye lasers was investigated and the potential for increased ion beam intensity, reliability, and reduced setup time has been demonstrated. In-source resonance ionization spectroscopy was performed at ISOLDE/CERN and at ISAC/TRIUMF radioactive ion beam facilities to develop an efficient and selective three-colour ionization scheme for the purely radioactive element astatine. A LabVIEW based monitoring, control and measurement system was conceived which enabled, in conjunction with Dual RILIS operation, the spectroscopy of high lying Rydberg states, from which the ionization potential of the astatine atom was determined for the first time experimentally.

  7. An all-solid state laser system for the laser ion sources RILIS and in-source laser spectroscopy of astatine at ISOLDE/CERN

    Energy Technology Data Exchange (ETDEWEB)

    Rothe, Sebastian

    2012-09-24

    This doctoral thesis describes the extension of the resonance ionization laser ion source RILIS at CERN/ISOLDE by the addition of an all-solid state tunable titanium:sapphire (Ti:Sa) laser system to complement the well-established system of dye lasers. Synchronous operation of the so called Dual RILIS system of Ti:Sa and dye lasers was investigated and the potential for increased ion beam intensity, reliability, and reduced setup time has been demonstrated. In-source resonance ionization spectroscopy was performed at ISOLDE/CERN and at ISAC/TRIUMF radioactive ion beam facilities to develop an efficient and selective three-colour ionization scheme for the purely radioactive element astatine. A LabVIEW based monitoring, control and measurement system was conceived which enabled, in conjunction with Dual RILIS operation, the spectroscopy of high lying Rydberg states, from which the ionization potential of the astatine atom was determined for the first time experimentally.

  8. Free-electron laser system with Raman amplifier outcoupling

    Energy Technology Data Exchange (ETDEWEB)

    Linford, G.J.

    1988-05-03

    A free-electron laser system is described comprising: a free-electron laser pump beam generator producing a high-power optical output beam in a vacuum environement; a Raman amplifier cell located in the path of the output beam from the pump beam generator; means for generating and introducing a Stokes seed beam into the Raman amplifier cell, a pair of gaseous windows through which the output beam enters and leaves the Raman amplifier cell, each window having a stream of gas moving continuously in a direction generally perpendicular to the beam; and a mirror positioned in the path of the output beam from the Raman amplifier, the mirror functioning to reflect and further direct the output beam, but not the unwanted spectral components.

  9. Analysis of a space debris laser removal system

    Science.gov (United States)

    Gjesvold, Evan; Straub, Jeremy

    2017-05-01

    As long as man ventures into space, he will leave behind debris, and as long as he ventures into space, this debris will pose a threat to him and his projects. Space debris must be located and decommissioned. Lasers may prove to be the ideal method, as they can operate at a distance from the debris, have a theoretically infinite supply of energy from the sun, and are a seemingly readily available technology. This paper explores the requirements and reasoning for such a laser debris removal method. A case is made for the negligibility of eliminating rotational velocity from certain systems, while a design schematic is also presented for the implementation of a cube satellite proof of concept.

  10. High-level PC-based laser system modeling

    Science.gov (United States)

    Taylor, Michael S.

    1991-05-01

    Since the inception of the Strategic Defense Initiative (SDI) there have been a multitude of comparison studies done in an attempt to evaluate the effectiveness and relative sizes of complementary, and sometimes competitive, laser weapon systems. It became more and more apparent that what the systems analyst needed was not only a fast, but a cost effective way to perform high-level trade studies. In the present investigation, a general procedure is presented for the development of PC-based algorithmic systems models for laser systems. This procedure points out all of the major issues that should be addressed in the design and development of such a model. Issues addressed include defining the problem to be modeled, defining a strategy for development, and finally, effective use of the model once developed. Being a general procedure, it will allow a systems analyst to develop a model to meet specific needs. To illustrate this method of model development, a description of the Strategic Defense Simulation - Design To (SDS-DT) model developed and used by Science Applications International Corporation (SAIC) is presented. SDS-DT is a menu-driven, fast executing, PC-based program that can be used to either calculate performance, weight, volume, and cost values for a particular design or, alternatively, to run parametrics on particular system parameters to perhaps optimize a design.

  11. Advanced Lyapunov control of a novel laser beam tracking system

    Science.gov (United States)

    Nikulin, Vladimir V.; Sofka, Jozef; Skormin, Victor A.

    2005-05-01

    Laser communication systems developed for mobile platforms, such as satellites, aircraft, and terrain vehicles, require fast wide-range beam-steering devices to establish and maintain a communication link. Conventionally, the low-bandwidth, high-steering-range part of the beam-positioning task is performed by gimbals that inherently constitutes the system bottleneck in terms of reliability, accuracy and dynamic performance. Omni-WristTM, a novel robotic sensor mount capable of carrying a payload of 5 lb and providing a full 180-deg hemisphere of azimuth/declination motion is known to be free of most of the deficiencies of gimbals. Provided with appropriate controls, it has the potential to become a new generation of gimbals systems. The approach we demonstrate describes an adaptive controller enabling Omni-WristTM to be utilized as a part of a laser beam positioning system. It is based on a Lyapunov function that ensures global asymptotic stability of the entire system while achieving high tracking accuracy. The proposed scheme is highly robust, does not require knowledge of complex system dynamics, and facilitates independent control of each channel by full decoupling of the Omni-WristTM dynamics. We summarize the basic algorithm and demonstrate the results obtained in the simulation environment.

  12. Cost-effectiveness analysis of orbital atherectomy plus balloon angioplasty vs balloon angioplasty alone in subjects with calcified femoropopliteal lesions.

    Science.gov (United States)

    Weinstock, Barry; Dattilo, Raymond; Diage, Tiffini

    2014-01-01

    As cost considerations become increasingly critical when selecting optimal endovascular treatment strategies, a cost-benefit analysis was conducted comparing the Diamondback 360°® Orbital Atherectomy System (OAS) (Cardiovascular Systems, Inc., St Paul, MN, USA) and balloon angioplasty (BA) vs BA alone for treatment of calcified femoropopliteal lesions. The clinical outcomes from COMPLIANCE 360°, a prospective, multicenter, randomized study comparing OAS+BA vs BA alone for treatment of calcified femoropopliteal lesions, were correlated with cost data and previously published quality of life data. Site of service, hospital charges, and associated medical resource utilization were obtained from Uniform Billing statements for index treatments and associated revascularizations out to 1 year. Hospital costs were estimated using hospital-specific, procedure-specific cost-to-charge ratios. Length of stay and procedural data were collected from participating study sites. Twenty-five subjects with 38 lesions and 25 subjects with 27 lesions were randomized to the OAS+BA and BA-alone groups, respectively. Mean hospital charges (US$51,755 vs US$39,922) and estimated hospital costs (US$15,100 vs US$11,016) were higher for OAS+BA compared with BA alone (not statistically significant). Stent utilization was statistically significantly higher with BA-alone treatment for all subjects (1.1 vs 0.1, P=0.001) and in the subset of subjects with one lesion (1.0 vs 0.1, Pcost for single-lesion versus multiple-lesion treatment. Using costs and quality-adjusted life years (QALYs) for the single-lesion cohort, the 1-year incremental cost of OAS+BA vs BA alone was US$549, and incremental QALY was 0.16. This results in an incremental cost-effectiveness ratio of US$3,441, well below the US$50,000 threshold. One-year index procedure cost and cost-effectiveness were comparable for OAS+BA vs BA alone. This study provides compelling cost-effectiveness data for using atherectomy for treatment of

  13. Cost-effectiveness analysis of orbital atherectomy plus balloon angioplasty vs balloon angioplasty alone in subjects with calcified femoropopliteal lesions

    Directory of Open Access Journals (Sweden)

    Weinstock B

    2014-03-01

    Full Text Available Barry Weinstock,1 Raymond Dattilo,2 Tiffini Diage3 1Orlando Health Heart Institute, Mid-Florida Cardiology Specialists, Orlando, FL, USA; 2Department of Cardiology, St Francis Health Center, Topeka, KS, USA; 3North American Science Association (NAMSA, Sunnyvale, CA, USA Introduction: As cost considerations become increasingly critical when selecting optimal endovascular treatment strategies, a cost-benefit analysis was conducted comparing the Diamondback 360°® Orbital Atherectomy System (OAS (Cardiovascular Systems, Inc., St Paul, MN, USA and balloon angioplasty (BA vs BA alone for treatment of calcified femoropopliteal lesions. Patients and methods: The clinical outcomes from COMPLIANCE 360°, a prospective, multicenter, randomized study comparing OAS+BA vs BA alone for treatment of calcified femoropopliteal lesions, were correlated with cost data and previously published quality of life data. Site of service, hospital charges, and associated medical resource utilization were obtained from Uniform Billing statements for index treatments and associated revascularizations out to 1 year. Hospital costs were estimated using hospital-specific, procedure-specific cost-to-charge ratios. Length of stay and procedural data were collected from participating study sites. Results: Twenty-five subjects with 38 lesions and 25 subjects with 27 lesions were randomized to the OAS+BA and BA-alone groups, respectively. Mean hospital charges (US$51,755 vs US$39,922 and estimated hospital costs (US$15,100 vs US$11,016 were higher for OAS+BA compared with BA alone (not statistically significant. Stent utilization was statistically significantly higher with BA-alone treatment for all subjects (1.1 vs 0.1, P=0.001 and in the subset of subjects with one lesion (1.0 vs 0.1, P<0.00001. There was a significant difference in cost for single-lesion versus multiple-lesion treatment. Using costs and quality-adjusted life years (QALYs for the single-lesion cohort, the 1-year

  14. Development of Broadband Telecommunication System for Railways using Laser Technology

    Science.gov (United States)

    Nakamura, Kazuki; Nakagawa, Shingo; Matsubara, Hiroshi; Tatsui, Daisuke; Seki, Kiyotaka; Haruyama, Shinichiro; Teraoka, Fumio

    We developed a high-speed telecommunication system applicable to railways, to improve customer service and efficiency of operator's telecommunication between the ground facilities and trains under operations. We manufactured a mobile telecommunication system, capable of recording the transfer rate of 1Gbps in theory by applying the laser beam communication technology. We carried out a field test using trains in active service, and obtained the result of the transfer rate of approximately 700Mbps on the TCP layer between the ground and the train running at a speed of approximately 130km/h.

  15. Surface characterization of weathered wood using a laser scanning system

    International Nuclear Information System (INIS)

    Arnold, M.; Lemaster, R.L.; Dost, W.A.

    1992-01-01

    Most of the existing methods to assess the effect of weathering on wood surfaces have some drawbacks that limit their use to specific tasks. The amount of surface erosion is often used as a measure for the weathering action. The application of a laser scanning system to reproduce surface profiles and to measure weathering erosion was tested on various samples and was found to be a very useful and superior alternative to existing methods. Further improvements of the system used can be made by refinements of the calibration procedures and by more comprehensive profile analyses. (author)

  16. Urinary incontinence monitoring system using laser-induced graphene sensors

    KAUST Repository

    Nag, Anindya

    2017-12-25

    This paper presents the design and development of a sensor patch to be used in a sensing system to deal with the urinary incontinence problem primarily faced by women and elderly people. The sensor patches were developed from laser-induced graphene from low-cost commercial polyimide (PI) polymers. The graphene was manually transferred to a commercial tape, which was used as sensor patch for experimentation. Salt solutions with different concentrations were tested to determine the most sensitive frequency region of the sensor. The results are encouraging to further develop this sensor in a platform for a fully functional urinary incontinence detection system.

  17. Ultrafast, ultrahigh-peak power Ti:sapphire laser system

    Energy Technology Data Exchange (ETDEWEB)

    Yamakawa, Koichi; Aoyama, Makoto; Matsuoka, Shinichi; Akahane, Yutaka; Kase, Teiji; Nakano, Fumihiko; Sagisaka, Akito [Advanced Photon Research Center, Kansai Research Establishment, Japan Atomic Energy Research Inst., Kizu, Kyoto (Japan)

    2001-01-01

    We review progress in the generation of multiterawatt optical pulses in the 10-fs range. We describe a design, performance and characterization of a Ti:sapphire laser system based on chirped-pulse amplification, which has produced a peak power in excess of 100-TW with sub-20-fs pulse durations and an average power of 19-W at a 10-Hz repetition rate. We also discuss extension of this system to the petawatt power level and potential applications in the relativistic, ultrahigh intensity regimes. (author)

  18. Laser heating of aqueous samples on a micro-optical-electro-mechanical system

    Science.gov (United States)

    Beer, Neil Reginald; Kennedy, Ian

    2013-02-05

    A system of heating a sample on a microchip includes the steps of providing a microchannel flow channel in the microchip; positioning the sample within the microchannel flow channel, providing a laser that directs a laser beam onto the sample for heating the sample; providing the microchannel flow channel with a wall section that receives the laser beam and enables the laser beam to pass through wall section of the microchannel flow channel without being appreciably heated by the laser beam; and providing a carrier fluid in the microchannel flow channel that moves the sample in the microchannel flow channel wherein the carrier fluid is not appreciably heated by the laser beam.

  19. Multi-wavelength study of PPDs using an OPO tunable pulse laser microscope system

    International Nuclear Information System (INIS)

    Yoshimura, Koji; Nakamura, Isamu

    2012-01-01

    We have developed a new pulsed laser microscope system whose wavelength is continuously tunable from 410 nm to 2200 nm by using an optical parametric oscillator (OPO) laser system. The laser spot can be focused to ∼2μm diameter, small enough to measure pixel-by-pixel performance of PPDs (pixelated photon detectors). Using multi-wavelength laser light, we plan to probe PPDs at various depths, thanks to their different penetration lengths in the silicon layer. In this paper, details of the commissioning of the laser microscope system and pilot measurements on a PPD at several wavelengths will be presented.

  20. Multi-wavelength study of PPDs using an OPO tunable pulse laser microscope system

    Energy Technology Data Exchange (ETDEWEB)

    Yoshimura, Koji, E-mail: koji.yoshimura@kek.jp [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Nakamura, Isamu [High Energy Accelerator Research Organization (KEK), 1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan)

    2012-12-11

    We have developed a new pulsed laser microscope system whose wavelength is continuously tunable from 410 nm to 2200 nm by using an optical parametric oscillator (OPO) laser system. The laser spot can be focused to {approx}2{mu}m diameter, small enough to measure pixel-by-pixel performance of PPDs (pixelated photon detectors). Using multi-wavelength laser light, we plan to probe PPDs at various depths, thanks to their different penetration lengths in the silicon layer. In this paper, details of the commissioning of the laser microscope system and pilot measurements on a PPD at several wavelengths will be presented.

  1. A Spectroscopic Comparison of Femtosecond Laser Modified Fused Silica using kHz and MHz Laser Systems.

    Energy Technology Data Exchange (ETDEWEB)

    Reichman, W J; Krol, D M; Shah, L; Yoshino, F; Arai, A; Eaton, S M; Herman, P R

    2005-09-29

    Waveguides were written in fused silica using both a femtosecond fiber laser with a 1 MHz pulse repetition rate and a femtosecond amplified Ti:sapphire laser with a 1 kHz repetition rate. Confocal Raman and fluorescence microscopy were used to study structural changes in the waveguides written with both systems. A broad fluorescence band, centered at 650 nm, associated with non-bridging oxygen hole center (NBOHC) defects was observed after waveguide fabrication with the MHz laser. With the kHz laser system these defects were only observed for pulse energies above 1 {mu}J. Far fewer NBOHC defects were formed with the MHz laser than with kHz writing, possibly due to thermal annealing driven by heat accumulation effects at 1 MHz. When the kHz laser was used with pulse energies below 1 {mu}J, the predominant fluorescence was centered at 550 nm, a band assigned to the presence of silicon clusters (E{prime}{sub {delta}}). We also observed an increase in the intensity of the 605 cm{sup -1} Raman peak relative to the total Raman intensity, corresponding to an increase in the concentration of 3-membered rings in the lines fabricated with both laser systems.

  2. Automated tracking for advanced satellite laser ranging systems

    Science.gov (United States)

    McGarry, Jan F.; Degnan, John J.; Titterton, Paul J., Sr.; Sweeney, Harold E.; Conklin, Brion P.; Dunn, Peter J.

    1996-06-01

    NASA's Satellite Laser Ranging Network was originally developed during the 1970's to track satellites carrying corner cube reflectors. Today eight NASA systems, achieving millimeter ranging precision, are part of a global network of more than 40 stations that track 17 international satellites. To meet the tracking demands of a steadily growing satellite constellation within existing resources, NASA is embarking on a major automation program. While manpower on the current systems will be reduced to a single operator, the fully automated SLR2000 system is being designed to operate for months without human intervention. Because SLR2000 must be eyesafe and operate in daylight, tracking is often performed in a low probability of detection and high noise environment. The goal is to automatically select the satellite, setup the tracking and ranging hardware, verify acquisition, and close the tracking loop to optimize data yield. TO accomplish the autotracking tasks, we are investigating (1) improved satellite force models, (2) more frequent updates of orbital ephemerides, (3) lunar laser ranging data processing techniques to distinguish satellite returns from noise, and (4) angular detection and search techniques to acquire the satellite. A Monte Carlo simulator has been developed to allow optimization of the autotracking algorithms by modeling the relevant system errors and then checking performance against system truth. A combination of simulator and preliminary field results will be presented.

  3. Qualification testing of fiber-based laser transmitters and on-orbit validation of a commercial laser system

    Science.gov (United States)

    Wright, M. W.; Wilkerson, M. W.; Tang, R. R.

    2017-11-01

    Qualification testing of fiber based laser transmitters is required for NASA's Deep Space Optical Communications program to mature the technology for space applications. In the absence of fully space qualified systems, commercial systems have been investigated in order to demonstrate the robustness of the technology. To this end, a 2.5 W fiber based laser source was developed as the transmitter for an optical communications experiment flown aboard the ISS as a part of a technology demonstration mission. The low cost system leveraged Mil Standard design principles and Telcordia certified components to the extent possible and was operated in a pressure vessel with active cooling. The laser was capable of high rate modulation but was limited by the mission requirements to 50 Mbps for downlinking stored video from the OPALS payload, externally mounted on the ISS. Environmental testing and space qualification of this unit will be discussed along with plans for a fully space qualified laser transmitter.

  4. Cryogenic-laser-fusion target implosion studies performed with the OMEGA uv-laser system

    International Nuclear Information System (INIS)

    Marshall, F.J.; Letzring, S.A.; Verdon, C.P.; Skupsky, S.; Keck, R.L.; Knauer, J.P.; Kremens, R.L.; Bradley, D.K.; Kessler, T.; Delettrez, J.; and others.

    1989-01-01

    A series of direct-drive laser-fusion implosion experiments was performed on cryogenically cooled, DT-filled glass microballoons with the OMEGA 24-beam uv (351-nm) laser system. The targets consisted of glass microballoons having radii of 100 to 150 μm, wall thicknesses of 3 to 7 μm, filled with DT gas at pressures of 75 to 100 atm. The targets were cooled to below the freezing point of DT, in situ, by a cryogenic target system. The targets were irradiated by approximately 1 to 1.2 kJ of uv light in 650-ps Gaussian pulses. The on-target irradiation uniformity was enhanced for these experiments by the use of distributed phase plates, which brought the estimated irradiation nonuniformities to ∼12% (σ rms ). Target performance was diagnosed by an array of x-ray, plasma, and nuclear instruments. The measured target performance showed ∼70% absorption, thermonuclear yields of 10 6 to 10 8 neutrons, and final fuel areal densities of 20 to 40 mg/cm 2 for the optimum targets examined in these experiments. Fuel densities at the time of thermonuclear neutron production, inferred from direct measurements of the fuel areal density, were in the range of 20 to 50 g/cm 3 (100 to 200 times the density of liquid DT) for the optimum targets

  5. Altimetric surveying with airborne laser system; Medicao altimetrica utilizando sistema a laser aerotransportado

    Energy Technology Data Exchange (ETDEWEB)

    Sallem Filho, Silas; Paoletto, Silvia M.; Bonatto, Amarildo [Esteio Engenharia, Curitiba, PR (Brazil)

    2003-07-01

    Airborne Laser Scanning (ALS) makes faster and more accurate the obtaining of Digital Elevation Model and Digital Terrain Model compared to conventional photogrammetry. The system generates Laser pulses towards the terrain, perpendicular to the flight line, scanning the terrain surface and recording the distances from the sensor to the soil for each pulse . The main characteristics of the system is the measurement of the first and the last return for each pulse, allowing the objects identification that are above the ground like vegetation. With this function it is possible the determination of volumes and biomass estimate, besides the virtual removal of vegetation covering. The Digital Terrain Models are used for Digital Orthophotos rectification and to obtain contour lines for topography maps. The correct points classification according the elevation, allows the identification of man-made features road and river crossings and human use in the the pipeline corridor. Some additional products, as hypsometric images and intensity images helps in the identification of features on pipeline projects as well as the obtaining of the obstacles height. (author)

  6. High speed real-time wavefront processing system for a solid-state laser system

    Science.gov (United States)

    Liu, Yuan; Yang, Ping; Chen, Shanqiu; Ma, Lifang; Xu, Bing

    2008-03-01

    A high speed real-time wavefront processing system for a solid-state laser beam cleanup system has been built. This system consists of a core2 Industrial PC (IPC) using Linux and real-time Linux (RT-Linux) operation system (OS), a PCI image grabber, a D/A card. More often than not, the phase aberrations of the output beam from solid-state lasers vary fast with intracavity thermal effects and environmental influence. To compensate the phase aberrations of solid-state lasers successfully, a high speed real-time wavefront processing system is presented. Compared to former systems, this system can improve the speed efficiently. In the new system, the acquisition of image data, the output of control voltage data and the implementation of reconstructor control algorithm are treated as real-time tasks in kernel-space, the display of wavefront information and man-machine conversation are treated as non real-time tasks in user-space. The parallel processing of real-time tasks in Symmetric Multi Processors (SMP) mode is the main strategy of improving the speed. In this paper, the performance and efficiency of this wavefront processing system are analyzed. The opened-loop experimental results show that the sampling frequency of this system is up to 3300Hz, and this system can well deal with phase aberrations from solid-state lasers.

  7. Large aperture components for solid state laser fusion systems

    International Nuclear Information System (INIS)

    Simmons, W.W.

    1978-01-01

    Solid state lasers for fusion experiments must reliably deliver maximum power to small (approximately .5 mm) targets from stand-off focal distances of 1 m or more. This requirement places stringent limits upon the optical quality, resistance to damage, and overall performance of the several major components--amplifiers, Faraday isolators, spatial filters--in each amplifier train. Component development centers about achieving (1) highest functional material figure of merit, (2) best optical quality, and (3) maximum resistance to optical damage. Specific examples of the performance of large aperture components will be presented within the context of the Argus and Shiva laser systems, which are presently operational at Lawrence Livermore Laboratory. Shiva comprises twenty amplifiers, each of 20 cm output clear aperture. Terawatt beams from these amplifiers are focused through two opposed, nested clusters of f/6 lenses onto such targets. Design requirements upon the larger aperture Nova laser components, up to 35 cm in clear aperture, will also be discussed; these pose a significant challenge to the optical industry

  8. Time-resolved laser-induced fluorescence system

    Science.gov (United States)

    Bautista, F. J.; De la Rosa, J.; Gallegos, F. J.

    2006-02-01

    Fluorescence methods are being used increasingly in the measurement of species concentrations in gases, liquids and solids. Laser induced fluorescence is spontaneous emission from atoms or molecules that have been excited by laser radiation. Here we present a time resolved fluorescence instrument that consists of a 5 μJ Nitrogen laser (337.1 nm), a sample holder, a quartz optical fiber, a spectrometer, a PMT and a PC that allows the measurement of visible fluorescence spectra (350-750 nm). Time response of the system is approximately 5 ns. The instrument has been used in the measurement of colored bond paper, antifreeze, diesel, cochineal pigment and malignant tissues. The data acquisition was achieved through computer control of a digital oscilloscope (using General Purpose Interface Bus GPIB) and the spectrometer via serial (RS232). The instrument software provides a graphic interface that lets make some data acquisition tasks like finding fluorescence spectra, and fluorescence lifetimes. The software was developed using the Lab-View 6i graphic programming package and can be easily managed in order to add more functions to it.

  9. The Laser Alignment System for the CMS silicon strip tracker

    CERN Document Server

    Olzem, Jan

    2009-01-01

    The Laser Alignment System (LAS) of the CMS silicon strip Tracker has been designed for surveying the geometry of the large-scale Tracker support structures. It uses 40 laser beams ($\\lambda$ = 1075 nm) that induce signals on a subset of the Tracker silicon sensors. The positions in space of the laser spots on the sensors are reconstructed with a resolution of 30 $\\mu$m. From this, the LAS is capable of permanent in-time monitoring of the different Tracker components relative to each other with better than 30 $\\mu$m precision. Additionally, it can provide an absolute measurement of the Tracker mechanical structure with an accuracy better than 70 $\\mu$m, thereby supplying additional input to the track based alignment at detector startup. 31 out of the 40 LAS beams have been successfully operated during the CMS cosmic muon data taking campaign in autumn 2008. The alignment of the Tracker Endcap Discs and of the discs with respect to the Tracker Inner Barrel and Tracker Outer Barrel subdetectors was measured w...

  10. Laser prostatectomy using a right angle delivery system

    Science.gov (United States)

    Trigo-Rocha, Flavio; Mitre, Anuar I.; Chavantes, Maria C.; Arap, Sami

    1995-05-01

    Benign prostate hyperplasia (BPH) represents a major health problem in old men. In the present transurethral resection of the prostate (TURP) is the gold standard treatment for BPH. Although TURP is related to low mortality rates its mobidity is quite high. To evaluate the efficacy and safety of a new surgical treatment for BPH we undertook 30 patients with symptomatic BPH. All of them were submitted to a laser prostatectomy using a lateral delivery system (non contact) connected to a Nd-YAG laser font. The preoperative evaluation showed a prostate weight ranging from 30,5 to 86 grams (mean equals 42,5). The preoperative prostatic specific antigen (PSA) ranged from 0,9 to 10,2 ng/dl (mean equals 4.3). The International prostate symptom score (I-PSS) ranged from 16 to 35 points (means equals 23,58). The flow rate ranged from 0 to m 12.8 ml/sec (mean equals 4,65) and the postvoid residual urine from 20 to 400 ml (mean equals 100). We obtained follow-up in 20 patients. After three months after the procedure the parameters were: I-PSS from 4 to 20 points (mean equals 7,0) p stenosis in one patient. We concluded that laser prostatectomy is a safe and effective treatment for BPH.

  11. Reflection effects in multimode fiber systems utilizing laser transmitters

    Science.gov (United States)

    Bates, Harry E.

    1991-11-01

    A number of optical communication lines are now in use at NASA-Kennedy for the transmission of voice, computer data, and video signals. Now, all of these channels use a single carrier wavelength centered near 1300 or 1550 nm. Engineering tests in the past have given indications of the growth of systematic and random noise in the RF spectrum of a fiber network as the number of connector pairs is increased. This noise seems to occur when a laser transmitter is used instead of a LED. It has been suggested that the noise is caused by back reflections created at connector fiber interfaces. Experiments were performed to explore the effect of reflection on the transmitting laser under conditions of reflective feedback. This effort included computer integration of some of the instrumentation in the fiber optic lab using the Lab View software recently acquired by the lab group. The main goal was to interface the Anritsu Optical and RF spectrum analyzers to the MacIntosh II computer so that laser spectra and network RF spectra could be simultaneously and rapidly acquired in a form convenient for analysis. Both single and multimode fiber is installed at Kennedy. Since most are multimode, this effort concentrated on multimode systems.

  12. Advances in lasers and optical micro-nano-systems

    Science.gov (United States)

    Laurell, F.; Fazio, E.

    2010-09-01

    Lasers represent a well consolidated technology: nevertheless, research in this field remains very active and productive, in both basic and applied directions. At the moment significant attention is given to those sources that bring together high power and compactness. Such high power lasers find important applications for material treatments and such applications are presented by Ehsani et al and Saiedeh Saghafi et al, in the treatment of dielectric thin films (Alteration of optical and morphological properties of polycarbonate illuminated by visible/IR laser beams) or of biological tissues like pistachio seeds (Investigating the effects of laser beams (532 and 660 nm) in annihilation of pistachio mould fungus using spectrophotometry analysis). In particular the latter paper show how laser sources can find very important applications in new domains, preserving goods and food without the need for preservatives or pesticides by simply sterilizing them using light. Optical Micro and Nano Systems presents a new domain for exploration. In this framework this special issue is very attractive, because it assembles papers reporting new results in three directions: new techniques for monitoring integrated micro- and nano-systems, new integrated systems and novel high performance metamaterial configurations. Integrated micro-components can be monitored and controlled using reflectance measurements as presented by Piombini et al (Toward the reflectance measurement of micro components). Speckle formation during laser beam reflection can also be a very sophisticated tool for detecting ultra-precise displacements, as presented by Filter et al (High resolution displacement detection with speckles : accuracy limits in linear displacement speckle metrology). Three dimensional integrated optical structures is indeed a big challenge and a peculiarity of photonics, they can be formed through traditional holography or using more sophisticated and novel ! technologies. Thus, special

  13. A Laser-Wire System for the International Linear Collider

    International Nuclear Information System (INIS)

    Delerue, N.; Dixit, S.; Gannaway, F.; Howell, D.; Qurshi, M.; Blair, G.; Boogert, S.; Boorman, G.; Driouichi, C.; Deacon, L.; Aryshev, A.; Karataev, P.; Terunuma, N.; Urakawa, J.; Brachmann, A.; Frisch, J.; Ross, M.

    2009-01-01

    A new laser-wire has been installed in the extraction line of the ATF at KEK. It aims at demonstrating that laser-wires can be used to measure micrometre scale beam size. In parallel, studies have been made to specify a laser suitable for the ILC laser-wires.

  14. X-ray lasers: from star wars to benchtop systems

    International Nuclear Information System (INIS)

    Kuba, J.; Limpouch, J.; Drska, L.

    2005-01-01

    The paper is structured as follows: The principle of X-ray lasers; The transient scheme - an X-ray laser (maybe) on a laboratory bench; The experimental parameters of transient lasers show promise; and The nuclear gamma laser is one of the feasible pathways. (P.A.)

  15. A laser-wire system for the International Linear Collider

    Indian Academy of Sciences (India)

    A new laser-wire has been installed in the extraction line of the ATF at KEK. It aims at demonstrating that laser-wires can be used to measure micrometre scale beam size. In parallel, studies have been made to specify a laser suitable for the ILC laser-wires.

  16. Percutaneous transluminal angioplasty of iliac and femoral arteries in severe lower-limb ischaemia

    DEFF Research Database (Denmark)

    Jørgensen, B; Henriksen, L O; Karle, A

    1988-01-01

    angioplasty) or persistent greater than or equal to 0.15 rise in arm/ankle blood pressure index (femoropopliteal angioplasty). The respective technical success rates were 82% and 64%. The complication rate was 10.9%, including 5.4% distal embolization. Patency rates were higher in iliac than...

  17. Impact of Diabetes on Long-Term Outcome After Primary Angioplasty

    DEFF Research Database (Denmark)

    De Luca, Giuseppe; Dirksen, Maurits T; Spaulding, Christian

    2012-01-01

    Diabetes has been shown to be associated with worse survival and repeat target vessel revascularization (TVR) after primary angioplasty. The aim of the current study was to evaluate the impact of diabetes on long-term outcome in patients undergoing primary angioplasty treated with bare metal sten...

  18. Percutaneous transluminal angioplasty of the superficial femoral artery by retrograde catheterization via the popliteal artery

    DEFF Research Database (Denmark)

    Tønnesen, K H; Sager, P; Karle, A

    1988-01-01

    We report the results of 50 angioplasty procedures via the popliteal artery. A 3-year follow-up including control of blood pressures at ankle and toe levels show results comparable to reports in the literature. This new approach for angioplasty of the superficial femoral artery and eventually of ...

  19. Laser systems configured to output a spectrally-consolidated laser beam and related methods

    Science.gov (United States)

    Koplow, Jeffrey P [San Ramon, CA

    2012-01-10

    A laser apparatus includes a plurality of pumps each of which is configured to emit a corresponding pump laser beam having a unique peak wavelength. The laser apparatus includes a spectral beam combiner configured to combine the corresponding pump laser beams into a substantially spatially-coherent pump laser beam having a pump spectrum that includes the unique peak wavelengths, and first and second selectively reflective elements spaced from each other to define a lasing cavity including a lasing medium therein. The lasing medium generates a plurality of gain spectra responsive to absorbing the pump laser beam. Each gain spectrum corresponds to a respective one of the unique peak wavelengths of the substantially spatially-coherent pump laser beam and partially overlaps with all other ones of the gain spectra. The reflective elements are configured to promote emission of a laser beam from the lasing medium with a peak wavelength common to each gain spectrum.

  20. Repetitive laser fusion experiment and operation using a target injection system

    International Nuclear Information System (INIS)

    Nishimura, Yasuhiko; Komeda, Osamu; Mori, Yoshitaka

    2017-01-01

    Since 2008, a collaborative research project on laser fusion development based on a high-speed ignition method using repetitive laser has been carried out with several collaborative research institutes. This paper reports the current state of operation of high repetition laser fusion experiments, such as target introduction and control based on a target injection system that allows free falling under 1 Hz, using a high repetition laser driver that has been under research and development, as well as the measurement of targets that freely fall. The HAMA laser driver that enabled high repetition fusion experiments is a titanium sapphire laser using a diode-pumped solid-state laser KURE-I of green light output as a driver pump light source. In order to carry out high repetition laser fusion experiments, the target injection device allows free falling of deuterated polystyrene solid sphere targets of 1 mm in diameter under 1 Hz. The authors integrated the developed laser and injection system, and succeeded first in the world in making the nuclear fusion reaction continuously by hitting the target to be injected with laser, which is essential technology for future laser nuclear fusion reactor. In order to realize repetition laser fusion experiments, stable laser, target synchronization control, and target position measurement technologies are indispensable. (A.O.)

  1. Anticipated chaos in a nonsymmetric coupled external-cavity-laser system

    International Nuclear Information System (INIS)

    Rees, Paul; Spencer, Paul S.; Pierce, Iestyn; Sivaprakasam, S.; Shore, K. Alan

    2003-01-01

    We explain how the anticipation of chaos in a coupled external cavity laser system described by Sivaprakasam, Shahverdiev, Spencer, and Shore [Phys. Rev. Lett. 87, 154101 (2001)] is obtained. We show that the external cavity induces the required symmetry breaking necessary for the existence of a time delay between the synchronized output of the two laser diodes. The inclusion of a detuning between the two lasers causes one laser to anticipate the chaotic dynamics of the other

  2. In-system Performance of MQW Lasers Exposed to High Magnetic Field

    CERN Document Server

    Jensen, Fredrik Bjorn Henning; Azevedo, C S; Cervelli, Giovanni; Gill, Karl; Grabit, Robert; Vasey, François

    2000-01-01

    The effect of magnetic field has been investigated on 1310nm edge-emitting multi-quantum-well lasers. These lasers are candidate transmitters for the CMS tracker optical link, which will be operated in a 4T solenoidal magnetic field. In-situ measurements up to 2.4T of in-system laser analogue performance and laser spectral characteristics were carried out. No degradation of performance and spectral characteristics was observed

  3. Fiber optic coherent laser radar 3D vision system

    International Nuclear Information System (INIS)

    Clark, R.B.; Gallman, P.G.; Slotwinski, A.R.; Wagner, K.; Weaver, S.; Xu, Jieping

    1996-01-01

    This CLVS will provide a substantial advance in high speed computer vision performance to support robotic Environmental Management (EM) operations. This 3D system employs a compact fiber optic based scanner and operator at a 128 x 128 pixel frame at one frame per second with a range resolution of 1 mm over its 1.5 meter working range. Using acousto-optic deflectors, the scanner is completely randomly addressable. This can provide live 3D monitoring for situations where it is necessary to update once per second. This can be used for decontamination and decommissioning operations in which robotic systems are altering the scene such as in waste removal, surface scarafacing, or equipment disassembly and removal. The fiber- optic coherent laser radar based system is immune to variations in lighting, color, or surface shading, which have plagued the reliability of existing 3D vision systems, while providing substantially superior range resolution

  4. Thermal Performance of ATLAS Laser Thermal Control System Demonstration Unit

    Science.gov (United States)

    Ku, Jentung; Robinson, Franklin; Patel, Deepak; Ottenstein, Laura

    2013-01-01

    The second Ice, Cloud, and Land Elevation Satellite mission currently planned by National Aeronautics and Space Administration will measure global ice topography and canopy height using the Advanced Topographic Laser Altimeter System {ATLAS). The ATLAS comprises two lasers; but only one will be used at a time. Each laser will generate between 125 watts and 250 watts of heat, and each laser has its own optimal operating temperature that must be maintained within plus or minus 1 degree Centigrade accuracy by the Laser Thermal Control System (LTCS) consisting of a constant conductance heat pipe (CCHP), a loop heat pipe (LHP) and a radiator. The heat generated by the laser is acquired by the CCHP and transferred to the LHP, which delivers the heat to the radiator for ultimate rejection. The radiator can be exposed to temperatures between minus 71 degrees Centigrade and minus 93 degrees Centigrade. The two lasers can have different operating temperatures varying between plus 15 degrees Centigrade and plus 30 degrees Centigrade, and their operating temperatures are not known while the LTCS is being designed and built. Major challenges of the LTCS include: 1) A single thermal control system must maintain the ATLAS at 15 degrees Centigrade with 250 watts heat load and minus 71 degrees Centigrade radiator sink temperature, and maintain the ATLAS at plus 30 degrees Centigrade with 125 watts heat load and minus 93 degrees Centigrade radiator sink temperature. Furthermore, the LTCS must be qualification tested to maintain the ATLAS between plus 10 degrees Centigrade and plus 35 degrees Centigrade. 2) The LTCS must be shut down to ensure that the ATLAS can be maintained above its lowest desirable temperature of minus 2 degrees Centigrade during the survival mode. No software control algorithm for LTCS can be activated during survival and only thermostats can be used. 3) The radiator must be kept above minus 65 degrees Centigrade to prevent ammonia from freezing using no more

  5. Carotid angioplasty and stent placement for restenosis after endarterectomy

    International Nuclear Information System (INIS)

    Kadkhodayan, Yasha; Moran, Christopher J.; Cross, DeWitte T.; Derdeyn, Colin P.

    2007-01-01

    Recurrent carotid stenosis following endarterectomy is a common complication, and reoperation may be associated with increased morbidity. The goal of this study was to determine the procedural safety and long-term complication rates of carotid angioplasty and stenting for recurrent stenosis. Of 248 consecutive carotid angioplasty and/or stenting procedures performed at our institution between March 1996 and November 2005, 83 procedures for recurrent stenosis following endarterectomy were performed in 75 patients (mean age 68 years; 43 men, 32 women) without cerebral protection devices. The patients' medical records were retrospectively reviewed for vascular imaging reports and available clinical follow-up. Procedural and long-term complication rates were calculated. Recurrent stenosis was reduced from a mean of 80.6% to no significant stenosis in 82 of 83 procedures. The procedural stroke rate was 3 out of 83 procedures (3.6%). The procedural transient ischemic attack (TIA) rate was 2 out of 83 procedures (2.4%). Mean follow-up was 22.4 months (range 0.1 to 86.7 months) with at least 6 months follow-up for 54 of 83 procedures (65%). There were five TIAs and no strokes on follow-up (new TIAs at 25.5 and 43.4 months; recurrent TIAs at 1, 11.1, and 12 months, all with normal angiograms). The composite 30-day stroke, myocardial infarction, or death rate was 5 of 83 procedures (6.0%). In this series, angioplasty and stenting were effective in relieving stenosis secondary to recurrent carotid disease after endarterectomy, and have low rates of ischemic complications. (orig.)

  6. Primary balloon angioplasty for symptomatic, high-grade intracranial stenosis.

    Science.gov (United States)

    Tomycz, Luke; Bansal, Neil K; Lockney, Tim; Strothers, Megan; Connors, John J; Shay, Scott; Singer, Robert J

    2013-01-01

    In light of recent controversy about the safety and efficacy of intracranial stenting, we sought to evaluate our experience with primary balloon angioplasty for symptomatic, high-grade intracranial stenosis. All intracranial angioplasty cases performed at Vanderbilt University Medical Center from 2006 to 2011 were retrospectively reviewed for degree of stenosis pre- and post-procedure. Immediate peri-procedural complications were evaluated as well as one-month and long-term outcomes. A total of 26 patients were included in the study with a mean age of 63.0 years and a mean follow-up of 350.2 days. The average pre-procedure stenosis was 71.2%. The immediate, average post-procedure stenosis was 46.6%, and the average post-procedure stenosis at last angiographic follow-up was 44.5%. Retreatment was required in only 3.8% of patients. The primary end-point of major stroke or death at 30 days was observed in 11.5%, and the overall intra-procedural complication rate was 7.7%. The incidence of stroke or death at last follow-up was 15.4%, which is comparable to the one-year stroke or death rate in the medical arm of the SAMPRISS trial. In this retrospective series, primary balloon angioplasty was found to be effective as a treatment option for symptomatic intracranial stenosis with the risk of stroke or death at 30 days higher than the medical arm of SAMPRIS but lower than the stenting arm. The one-year risk of stroke was comparable to that reported for the one-year outcomes in the SAMPRISS medical arm.

  7. Design of single-longitudinal-mode laser oscillator for edge Thomson scattering system in ITER

    International Nuclear Information System (INIS)

    Hatae, Takaki; Kusama, Yoshinori; Kubomura, Hiroyuki; Matsuoka, Shin-ichi

    2006-06-01

    A high output energy (5J) and high repetition rate (100 Hz) laser system is required for the edge Thomson scattering system in ITER. A YAG laser (Nd:YAG laser) is a first candidate for the laser system satisfying the requirements. It is important to develop a high beam quality and single longitudinal mode (SLM) laser oscillator in order to realize this high power laser system. In this design work, following activities relating to the SLM laser oscillator have been carried out: design of the laser head and the resonator, estimation of the output power for the SLM laser oscillator, consideration of the feedback control scheme and consideration of interface for amplification system to achieve required performance (5J, 100 Hz). It is expected that the designed laser diode (LD) pumped SLM laser oscillator realizes: 100 Hz of repetition rate, 10 mJ of output energy, 10 ns of pulse width, single longitudinal mode, TEM 00 of transversal mode, divergence less than 4 times of the diffraction limit, energy stability within 5%. (author)

  8. 970-nm ridge waveguide diode laser bars for high power DWBC systems

    Science.gov (United States)

    Wilkens, Martin; Erbert, Götz; Wenzel, Hans; Knigge, Andrea; Crump, Paul; Maaßdorf, Andre; Fricke, Jörg; Ressel, Peter; Strohmaier, Stephan; Schmidt, Berthold; Tränkle, Günther

    2018-02-01

    de lasers are key components in material processing laser systems. While mostly used as pump sources for solid state or fiber lasers, direct diode laser systems using dense wavelength multiplexing have come on the market in recent years. These systems are realized with broad area lasers typically, resulting in beam quality inferior to disk or fiber lasers. We will present recent results of highly efficient ridge waveguide (RW) lasers, developed for dense-wavelength-beamcombining (DWBC) laser systems expecting beam qualities comparable to solid state laser systems and higher power conversion efficiencies (PCE). The newly developed RW lasers are based on vertical structures with an extreme double asymmetric large optical cavity. Besides a low vertical divergence these structures are suitable for RW-lasers with (10 μm) broad ridges, emitting in a single mode with a good beam quality. The large stripe width enables a lateral divergence below 10° (95 % power content) and a high PCE by a comparably low series resistance. We present results of single emitters and small test arrays under different external feedback conditions. Single emitters can be tuned from 950 nm to 975 nm and reach 1 W optical power with more than 55 % PCE and a beam quality of M2 < 2 over the full wavelength range. The spectral width is below 30 pm FWHM. 5 emitter arrays were stabilized using the same setup. Up to now we reached 3 W optical power, limited by power supply, with 5 narrow spectral lines.

  9. Noncontact inspection laser system for characterization of piezoelectric samples

    International Nuclear Information System (INIS)

    Jimenez, F.J.; Frutos, J. de

    2004-01-01

    In this work measurements on a piezoelectric sample in dynamic behavior were taken, in particular, around the frequencies of resonance for the sample where the nonlineal effects are accentuated. Dimension changes in the sample need to be studied as that will allow a more reliable characterization of the piezoelectric samples. The goal of this research is to develop an inspection system able to obtain measurements, using a noncontact laser displacement transducer, also able to visualize, in three-dimensional graphic environment, the displacement that takes place in a piezoelectric sample surface. In resonant mode, the vibration mode of the sample is visualized

  10. A laser-based eye-tracking system.

    Science.gov (United States)

    Irie, Kenji; Wilson, Bruce A; Jones, Richard D; Bones, Philip J; Anderson, Tim J

    2002-11-01

    This paper reports on the development of a new eye-tracking system for noninvasive recording of eye movements. The eye tracker uses a flying-spot laser to selectively image landmarks on the eye and, subsequently, measure horizontal, vertical, and torsional eye movements. Considerable work was required to overcome the adverse effects of specular reflection of the flying-spot from the surface of the eye onto the sensing elements of the eye tracker. These effects have been largely overcome, and the eye-tracker has been used to document eye movement abnormalities, such as abnormal torsional pulsion of saccades, in the clinical setting.

  11. LASER monitoring system for the ATLAS Tile Calorimeter

    International Nuclear Information System (INIS)

    Viret, S.

    2010-01-01

    The ATLAS detector at the Large Hadron Collider (LHC) at CERN uses a scintillator-iron technique for its hadronic Tile Calorimeter (TileCal). Scintillating light is readout via 9852 photomultiplier tubes (PMTs). Calibration and monitoring of these PMTs are made using a LASER based system. Short light pulses are sent simultaneously into all the TileCal photomultiplier's tubes (PMTs) during ATLAS physics runs, thus providing essential information for ATLAS data quality and monitoring analyses. The experimental setup developed for this purpose is described as well as preliminary results obtained during ATLAS commissioning phase in 2008.

  12. Optical components of adaptive systems for improving laser beam quality

    Science.gov (United States)

    Malakhov, Yuri I.; Atuchin, Victor V.; Kudryashov, Aleksis V.; Starikov, Fedor A.

    2008-10-01

    The short overview is given of optical equipment developed within the ISTC activity for adaptive systems of new generation allowing for correction of high-power laser beams carrying optical vortices onto the phase surface. They are the kinoform many-level optical elements of new generation, namely, special spiral phase plates and ordered rasters of microlenses, i.e. lenslet arrays, as well as the wide-aperture Hartmann-Shack sensors and bimorph deformable piezoceramics- based mirrors with various grids of control elements.

  13. Optical performance of the Gemini carbon dioxide laser fusion system

    International Nuclear Information System (INIS)

    Viswanathan, V.K.; Hayden, J.J.; Liberman, I.

    1979-01-01

    The performance of the Gemini two beam carbon dioxide laser fusion system was recently upgraded by installation of optical components with improved quality in the final amplifier. A theoretical analysis was conducted in conjunction with measurements of the new performance. The analysis and experimental procedures, and results obtained are reported and compared. Good agreement was found which was within the uncertainties of the analysis and the inaccuracies of the experiments. The focal spot Strehl ratio was between 0.24 and 0.3 for both beams

  14. Handling And Safety Aspects Of Fiber Optic Laser Beam Delivery Systems

    Science.gov (United States)

    Schonborn, K.-H.; Wodrich, W.

    1988-06-01

    Using lasers for therapeutic applications is getting more and more accepted. In ophthalmology Ar-lasers for intraocular applications are quite common. The Nd:YAG-laser is used as a high power tool in connection with silica fibers for different extracorporal and intracorporal applications. The CO2-laser is the cutting laser, one problem being the beam transmission: The state of the art in fibers is not sufficient up to now. Because of the high power used safety against laser radiation hazard is of great importance. The safety in laser use is primarily dependent on the surgeons cautiousness, e.g. using laser protection goggels, observing that the spot of the aiming beam is present etc. On the other hand the laser and fiber system has to be inherently safe by appropriate technical means as far as possible. An additional aspect adding to safety is the handling: With easier system handling less attention of the surgeon is necessary for driving the apparatus. Thus he can concentrate on the patient and on the procedure. In considering the fiber system one important point in handling and safety is the coupling of the fiber to the laser head. The development philosophy in this coupling may be divided into two groups: - one is trying to use standard connectors which were initially developed for data transmission; - the other is using special connectors. One example of the first group is the guiding of the laser beam from the Ar-laser to the slit-lamp in ophtalmology. Here the well-known F-SMA connectors together with a special fiber with adapted numerical aperture are used. The advantage of such a system is the low price of the connector. For high power lasers such as the clinical Nd:YAG lasers with 40 to 150 W those connectors are not suitable. Up to now every laser manufacturer developed his own connector system in this field.

  15. Aurora multikilojoule KrF laser system prototype for inertial confinement fusion

    International Nuclear Information System (INIS)

    Rosocha, L.A.; Hanlon, J.A.; Mc Leod, J.; Kang, M.; Kortegaard, B.L.; Burrows, M.D.; Bowling, P.S.

    1987-01-01

    Aurora is the Los Alamos National Laboratory short-pulse, high-power, KrF laser system. It serves as an end-to-end technology demonstration for large-scale ultraviolet laser systems of interest for short wavelength, inertial confinement fusion (ICF) investigations. The systems is a prototype for using optical angular multiplexing and serial amplification by large electron-beam-driven KrF laser amplifiers to deliver stacked, 248-nm, 5-ns duration multikilojoule laser pulses to ICF targets using an --1-km-long optical beam path. The entire Aurora KrF laser system is described and the design features of the following major system components are summarized: front-end lasers, amplifier train, multiplexer, optical relay train, demultiplexer, target irradiation apparatus, and alignment and controls systems

  16. Study on high power ultraviolet laser oil detection system

    Science.gov (United States)

    Jin, Qi; Cui, Zihao; Bi, Zongjie; Zhang, Yanchao; Tian, Zhaoshuo; Fu, Shiyou

    2018-03-01

    Laser Induce Fluorescence (LIF) is a widely used new telemetry technology. It obtains information about oil spill and oil film thickness by analyzing the characteristics of stimulated fluorescence and has an important application in the field of rapid analysis of water composition. A set of LIF detection system for marine oil pollution is designed in this paper, which uses 355nm high-energy pulsed laser as the excitation light source. A high-sensitivity image intensifier is used in the detector. The upper machine sends a digital signal through a serial port to achieve nanoseconds range-gated width control for image intensifier. The target fluorescence spectrum image is displayed on the image intensifier by adjusting the delay time and the width of the pulse signal. The spectral image is coupled to CCD by lens imaging to achieve spectral display and data analysis function by computer. The system is used to detect the surface of the floating oil film in the distance of 25m to obtain the fluorescence spectra of different oil products respectively. The fluorescence spectra of oil products are obvious. The experimental results show that the system can realize high-precision long-range fluorescence detection and reflect the fluorescence characteristics of the target accurately, with broad application prospects in marine oil pollution identification and oil film thickness detection.

  17. Annular beam shaping system for advanced 3D laser brazing

    Science.gov (United States)

    Pütsch, Oliver; Stollenwerk, Jochen; Kogel-Hollacher, Markus; Traub, Martin

    2012-10-01

    As laser brazing benefits from advantages such as smooth joints and small heat-affected zones, it has become established as a joining technology that is widely used in the automotive industry. With the processing of complex-shaped geometries, recent developed brazing heads suffer, however, from the need for continuous reorientation of the optical system and/or limited accessibility due to lateral wire feeding. This motivates the development of a laser brazing head with coaxial wire feeding and enhanced functionality. An optical system is designed that allows to generate an annular intensity distribution in the working zone. The utilization of complex optical components avoids obscuration of the optical path by the wire feeding. The new design overcomes the disadvantages of the state-of-the-art brazing heads with lateral wire feeding and benefits from the independence of direction while processing complex geometries. To increase the robustness of the brazing process, the beam path also includes a seam tracking system, leading to a more challenging design of the whole optical train. This paper mainly discusses the concept and the optical design of the coaxial brazing head, and also presents the results obtained with a prototype and selected application results.

  18. Long-term results of brachiocephalic artery percutaneous transluminal angioplasty

    International Nuclear Information System (INIS)

    Mc Namara, T.O.; Gardner, K.

    1990-01-01

    This paper establishes the ling-term and angiographic sequelae of percutaneous transluminal angioplasty (PTA) of stenoses of the origins of the brachycephalic arteries. From November of the proximal segments of the brachycephalic arteries. Clinical follow-up after PTA was 45 months. Two patients had recurrence of vertigo, after 16 and 75 months. There was no evidence of restenosis in the patient whose recurrence was after 16 months, but considerable restenosis was noted in the patient whose symptoms recurred after 75 months. That patient underwent successful repeated PTA

  19. Endovascular stent-support angioplasty for cerebral venous sinus stenosis

    Directory of Open Access Journals (Sweden)

    Xin-feng LI

    2011-06-01

    Full Text Available Objective To investigate the pathophysiological features of cerebral venous sinus stenosis,and the modus and therapeutic effect of stent-support angioplasty.Methods The clinical data of 36 patients with cerebral venous sinus stenosis,admitted to Neurosurgical Department of General Hospital of PLA from Dec.2001 to Jun.2010,were retrospectively analyzed.Of the 36 cases,10 were males and 26 females,aged from 14 to 57 years with a mean of 37.8 years,and the disease course ranged from 4 days to 9 years.The main clinical manifestations included headache,vomiting,optical visual blurring,and limb weakness with anesthesia in some patients.The diagnosis of all patients was confirmed by digital subtraction angiography,and the results showed that the local stenosis located in right transverse-sigmoid sinus in 21 cases,left transverse-sigmoid sinus in 12 cases,and on both sides in 3 cases.All patients received thrombolytic therapy via carotid artery or a microcatheter inserted in the venous sinus,followed by stent angioplasty of venous sinus.Meanwhile,general anticoagulant and antiplatelet therapy were essential.Results All the 36 patients were successively treated with balloon dilatation and stent angioplasty of venous sinus with exception of 3 cases,who failed because of the circuitous jugular foramen preventing the insertion of the stent.The successful rate was 91.7%.The cerebrospinal fluid pressure of the patients was lowered from 374.7±82.9mmH2O before operation to 230.3±48.1mmH2O after operation.Thirty-three patients were followed-up for 1 month to 8 years by brain angiography and examinations in the outpatient clinic.Among them 32 showed persistent relief of clinical symptoms.The remaining patient presented severe headache and optical visual blurring 1 month after stent implantation,however the symptoms were alleviated obviously after thrombolytic therapy via the carotid artery with adequate anticoagulation.Conclusions Stent angioplasty of venous

  20. Risk assessment after coronary angioplasty with SPECT myocardial perfusion studies

    International Nuclear Information System (INIS)

    Camilletti, Jorge A.; Erriest, Juan; Mele, Anibal A.

    2007-01-01

    The chest pain can be use for stratifying the risk of the patients after coronary angioplasty. Nevertheless this strategy has shown to have a low accuracy in the detection of restenosis and myocardial ischemia. Aims: To establish the usefulness of the SPECT studies in the risk stratification after the coronary angioplasty. Evaluate the incidence of silent ischemia or symptomatic, and its impact on the prognosis. Method: There were included 107 patients (p) submitted to a gated SPECT between the year of the coronary angioplasty. The analysis of the images was performed according to different scores (SSS, SRS, SDS). These data was correlated with the symptoms of the patients. We define group 1 (G1) as the asymptomatic without ischemia (n 59p), group 2 (G2) as silent ischemia (n = 28p) and group 3 (G3) as symptomatic with ischemia (n = 20p). A clinical follow-up was done in search of events (target vessel revascularization, unstable angina, AMI and death). Results: Significant differences were not observed in the clinical variables between the different groups. The SSS was lower in the G1 compare with G2 and G3 (p 0.0001) and was similar between the last two, p = NS (SSS: G1: 2.2 ± 4.9; G2: 7.6 ± 5.9; G3: 9.5 ± 6.8). The SDS was greater in G3 vs. G1 and G2, p = 0.0001, and greater in G2 vs. G1, p = 0.0001 (SDS: G1: 0; G2: 4.8 ± 3.5; G3: 7.2 ± 6.5). No differences where observed in the SRS between the three groups. In the follow-up the total percentage of events was lesser when compare the G1 with the G2 and G3 (G1: 3.3%; G2 and G3: 18.7%; p 0.02). The percentage of annual events of the G3 symptomatic with ischemia (11.03%) and G2 silent ischemia (4.04%) did not present differences (p 0.7). When the events of the G2 (4.04%) were compared with the G1 (1.24%) we observed a trend to major frequency of events in the G2 (p = 0.6). Conclusions: The presence of myocardial ischemia after coronary angioplasty is a determinant of the prognosis. Nevertheless, the extension

  1. Subintimal angioplasty in femoropopliteal region-Mid-term results

    International Nuclear Information System (INIS)

    Koecher, Martin; Cerna, Marie; Utikal, Petr; Kozak, Jiri; Sisola, Ivan; Thomas, Rohit P.; Bachleda, Petr; Drac, Petr; Sekanina, Zdenek; Langova, Katerina

    2010-01-01

    Purpose: Subintimal angioplasty is becoming more frequently used treatment option for patients with long arterial occlusions or diffuse atherosclerotic changes as an alternative to surgical treatment in claudicants especially in patients with critical limb ischemia. The aim of our article is to retrospectively assess mid-term outcomes of subintimal angioplasty of chronic arterial occlusions in femoropopliteal region followed clinically and by Doppler ultrasonography. Materials and methods: From May 2002 to December 2007, 133 femoropopliteal artery occlusions in 123 patients were indicated for subintimal recanalisation. The indications for treatment were intermittent claudications in 84 patients (63.15%) and critical limb ischemia in 49 patients (36.85%). The median length of lesions was 11.4 cm, range 2-30 cm. Except doppler ultrasonographic examination done 24 h after the procedure and clinical examination before discharge, both clinical and ultrasonographic examinations were performed 6 and 12 months after the procedure and yearly thereafter. Statistical analysis of our cohort was performed by Kaplan-Meier analysis, log-rank test and Cox regression. Results: Technical success was achieved in 86.46%. Primary patency rate was 83.1% (SE: 3.9%), 67.5% (SE: 5%), 58% (SE: 5.9%) a 48.4% (SE: 7.1%) at 6, 12, 24 and 36 months respectively. No statistically significant difference of primary patency was found between the group of claudicants and the group of patient with critical limb ischemia. Statistically significant prediction factors for primary patency were only the quality of the run off and the length of the occlusion. Limb salvage rate in our group of patients with critical limb ischemia was 80.8% at 12 months. Conclusion: Subintimal recanalisation is a simple and safe procedure for treatment of chronic peripheral arterial occlusions with high primary technical success rate, acceptable primary patency rate, low percentage of complications and mortality is as low as

  2. Development of laser cladding system to repair wall thinning of 1-inch heat exchanger tube

    International Nuclear Information System (INIS)

    Terada, Takaya

    2013-01-01

    We developed a laser cladding system to repair the inner wall wastage of heat exchanger tubes. Our system, which is designed to repair thinning tube walls within 100 mm from the edge of a heat exchanger tube, consists of a fiber laser, a composite-type optical fiberscope, a coupling device, a laser processing head, and a wire-feeding device. All of these components were reconfigured from the technologies of FBR maintenance. The laser processing head, which has a 15-mm outer diameter, was designed to be inserted into a 1-inch heat exchanger tube. We mounted a heatproof broadband mirror for laser cladding and fiberscope observation with visible light inside the laser processing head. The wire-feeding device continuously supplied 0.4-mm wire to the laser irradiation spot with variable feeding speeds from 0.5 to 20 mm/s. We are planning to apply our proposed system to the maintenance of aging industrial plants. (author)

  3. A miniaturized laser-Doppler-system in the ear canal

    Science.gov (United States)

    Schmidt, T.; Gerhardt, U.; Kupper, C.; Manske, E.; Witte, H.

    2013-03-01

    Gathering vibrational data from the human middle ear is quite difficult. To this date the well-known acoustic probe is used to estimate audiometric parameters, e.g. otoacoustic emissions, wideband reflectance and the measurement of the stapedius reflex. An acoustic probe contains at least one microphone and one loudspeaker. The acoustic parameter determination of the ear canal is essential for the comparability of test-retest measurement situations. Compared to acoustic tubes, the ear canal wall cannot be described as a sound hard boundary. Sound energy is partly absorbed by the ear canal wall. In addition the ear canal features a complex geometric shape (Stinson and Lawton1). Those conditions are one reason for the inter individual variability in input impedance measurement data of the tympanic membrane. The method of Laser-Doppler-Vibrometry is well described in literature. Using this method, the surface velocity of vibrating bodies can be determined contact-free. Conventional Laser-Doppler-Systems (LDS) for auditory research are mounted on a surgical microscope. Assuming a free line of view to the ear drum, the handling of those laser-systems is complicated. We introduce the concept of a miniaturized vibrometer which is supposed to be applied directly in the ear canal for contact-free measurement of the tympanic membrane surface vibration. The proposed interferometer is based on a Fabry-Perot etalon with a DFB laser diode as light source. The fiber-based Fabry-Perot-interferometer is characterized by a reduced size, compared to e.g. Michelson-, or Mach-Zehnder-Systems. For the determination of the phase difference in the interferometer, a phase generated carrier was used. To fit the sensor head in the ear canal, the required shape of the probe was generated by means of the geometrical data of 70 ear molds. The suggested prototype is built up by a singlemode optical fiber with a GRIN-lens, acting as a fiber collimator. The probe has a diameter of 1.8 mm and a

  4. Transmission media appropriate laser-microwave solar power satellite system

    Science.gov (United States)

    Schäfer, C. A.; Gray, D.

    2012-10-01

    As a solution to the most critical problems with Solar power Satellite (SPS) development, a system is proposed which uses laser power transmission in space to a receiver high in the atmosphere that relays the power to Earth by either cable or microwave power transmission. It has been shown in the past that such hybrid systems have the advantages of a reduction in the mass of equipment required in geostationary orbit and avoidance of radio frequency interference with other satellites and terrestrial communications systems. The advantage over a purely laser power beam SPS is that atmospheric absorption is avoided and outages due to clouds and precipitation will not occur, allowing for deployment in the equatorial zone and guaranteeing year round operation. This proposal is supported by brief literature surveys and theoretical calculations to estimate crucial parameters in this paper. In relation to this concept, we build on a recently proposed method to collect solar energy by a tethered balloon at high altitude because it enables a low-cost start for bringing the first Watt of power to Earth giving some quick return on investment, which is desperately missing in the traditional SPS concept. To tackle the significant problem of GW-class SPSs of high launch cost per kg mass brought to space, this paper introduces a concept which aims to achieve a superior power over mass ratio compared to traditional satellite designs by the use of thin-film solar cells combined with optical fibres for power delivery. To minimise the aperture sizes and cost of the transmitting and receiving components of the satellite and high altitude receiver, closed-loop laser beam pointing and target tracking is crucial for pointing a laser beam onto a target area that is of similar size to the beam's diameter. A recently developed technique based on optical phase conjugation is introduced and its applicability for maintaining power transmission between the satellite and high altitude receiver is

  5. The control and data acquisition system of a laser in-vessel viewing system

    International Nuclear Information System (INIS)

    Pereira, Rita C.; Cruz, Nuno; Neri, C.; Riva, M.; Correia, C.; Varandas, C.A.F.

    2000-01-01

    This paper presents the dedicated control and data acquisition system (CADAS) of a new laser in-vessel viewing system that has been developed for inspection purposes in fusion experiments. CADAS is based on a MC68060 microprocessor and on-site developed VME instrumentation. Its main aims are to simultaneously control the laser alignment system as well as the laser beam deflection for in-vessel scanning, acquire a high-resolution image and support real-time data flow rates up to 2 Mbyte/s from the acquisition modules to the hard disk and network. The hardware (modules for control and alignment acquisition, scanning acquisition and monitoring) as well as the three levels of software are described

  6. Percutaneous transluminal angioplasty in the region of the renal artery: indications, technique and results

    Energy Technology Data Exchange (ETDEWEB)

    Olbert, F; Ogris, E; Muzika, N; Schlegl, A; Vacariu, O; Diez, W

    1985-01-01

    The paper reports the results obtained by percutaneous transluminal angioplasty (PTA) in the treatment of renal artery stenosis in 25 patients with secondary hypertension and discusses indications and the technique used. The follow-up period ranged from 0.5 to 12 months. All interventions were performed with the Olbert catheter system. Following PTA a significant decrease in systolic, diastolic and mean arterial pressure was observed in nearly all patients. The response of the plasma renin activity (PRA) to orthostatic stimulation and pharmacological stimulation by furosemide was determined in a subset of 15 patients before and after PTA. A significant decrease in both basal and stimulated PRA values was observed subsequent to PTA. The decrease in PRA values after successful PTA did not, however, correlate with the extent of the blood pressure changes. (Author).

  7. Percutaneous transluminal angioplasty in the region of the renal artery: indications, technique and results

    International Nuclear Information System (INIS)

    Olbert, F.; Ogris, E.; Muzika, N.; Schlegl, A.; Vacariu, O.; Diez, W.

    1985-01-01

    The paper reports the results obtained by percutaneous transluminal angioplasty (PTA) in the treatment of renal artery stenosis in 25 patients with secondary hypertension and discusses indications and the technique used. The follow-up period ranged from 0.5 to 12 months. All interventions were performed with the Olbert catheter system. Following PTA a significant decrease in systolic, diastolic and mean arterial pressure was observed in nearly all patients. The response of the plasma renin activity (PRA) to orthostatic stimulation and pharmacological stimulation by furosemide was determined in a subset of 15 patients before and after PTA. A significant decrease in both basal and stimulated PRA values was observed subsequent to PTA. The decrease in PRA values after successful PTA did not, however, correlate with the extent of the blood pressure changes. (Author)

  8. Impact of the Intracoronary Rendezvous technique on coronary angioplasty for chronic total occlusion.

    Science.gov (United States)

    Nihei, Taro; Yamamoto, Yoshito; Kudo, Shun; Hanawa, Kenichiro; Hasebe, Yuhi; Takagi, Yusuke; Minatoya, Yutaka; Sugi, Masafumi; Shimokawa, Hiroaki

    2017-10-01

    The Rendezvous technique, which requires bidirectional wiring, is one of the useful methods for improving the success rate of recanalization for chronic total occlusion (CTO) in the field of peripheral intervention. Recently, advanced new devices for percutaneous coronary intervention have enabled us to perform the Rendezvous technique for peripheral as well as for coronary CTO lesions. We used the Intracoronary Rendezvous technique to perform angioplasty for coronary CTO. "Intracoronary Rendezvous" means that Rendezvous was achieved within the CTO lesion. From March 2009 to November 2015, 189 patients underwent CTO angioplasty at our institute, and we treated 10 patients with the Intracoronary Rendezvous technique. This technique involves crossing the Gaia series guidewire to the contralateral Corsair microcatheter located inside the plaque of CTO lesions. The majority of the CTO sites examined were in the proximal RCA (60 %). Lesion length of the occlusion was relatively long (64.4 ± 12.2 mm). Using the biplane imaging system, we were able to control the Gaia guidewires in a specific direction. Furthermore, if the antegrade and retrograde wires can be advanced into contiguous space inside the CTO lesion, we intentionally entered either wire into the contralateral Corsair microcatheter, followed by successful CTO crossing. CTO recanalization was completed for all patients without controlled antegrade retrograde subintimal tracking (CART) or reverse CART. No major complications occurred during hospitalization. These results indicate that the Rendezvous technique, assisted by new devices and a biplane imaging system, represents one of the primary options to achieve successful coronary CTO recanalization.

  9. A randomized trial comparing primary angioplasty versus stent placement for symptomatic intracranial stenosis

    Science.gov (United States)

    Qureshi, Adnan I; Chaudhry, Saqib A; Siddiq, Farhan; Majidi, Shahram; Rodriguez, Gustavo J; Suri, M Fareed K

    2013-01-01

    Background: Both primary angioplasty alone and angioplasty with a self-expanding stent have been compared in non-randomized concurrent clinical studies that suggest equivalent results. However, there is no randomized trial that has compared the two procedures in patients with symptomatic high grade intracranial stenosis. Objective: The primary aim of the randomized trial was to compare the clinical and angiographic efficacy of primary angioplasty and angioplasty followed by stent placement in preventing restenosis, stroke, requirement for second treatment, and death in patients with symptomatic intracranial stenosis. Methods: The study prospectively evaluated efficacy and safety of the two existing neurointerventional techniques for treatment of moderate intracranial stenosis (stenosis ≥ 50%) with documented failure of medical treatment or severe stenosis (≥70%) with or without failure of medical treatment. Results: A total of 18 patients were recruited in the study (mean age [±SD] was 64.7 ± 15.1 years); out of these, 12 were men. Of these 18, 10 were treated with primary angioplasty and 8 were treated with angioplasty followed by self-expanding stent. The technical success rates of intracranial angioplasty and stent placements defined as ability to achieve <30% residual stenosis when assessed by immediate post-procedure angiography was 5 of 10 and 5 of 8 patients, respectively. The total fluoroscopic time (mean [±SD]) was lower in patients undergoing primary angioplasty 37 [±11] min versus those undergoing angioplasty followed by self-expanding stent 42 [±15] min, P = 0.4321. The stroke and death rate within 1 month was very low in both patient groups (1 of 10 versus 0 of 8 patients). One patient randomized to stent placement continued to have recurrent ischemic symptoms requiring another angioplasty in the vertebral artery on post-procedure Day 2. Conclusions: The trial suggests that a randomized trial comparing primary angioplasty to angioplasty

  10. Physics of laser fusion. Volume IV. The future development of high-power solid-state laser systems

    International Nuclear Information System (INIS)

    Emmett, J.L.; Krupke, W.F.; Trenholme, J.B.

    1982-11-01

    Solid state lasers, particularly neodymium glass systems, have undergone intensive development during the last decade. In this paper, we review solid state laser technology in the context of high-peak-power systems for inertial confinement fusion. Specifically addressed are five major factors: efficiency, wavelength flexibility, average power, system complexity, and cost; these factors today limit broader application of the technology. We conclude that each of these factors can be greatly improved within current fundamental physical limits. We further conclude that the systematic development of new solid state laser madia, both vitreous and crystalline, should ultimately permit the development of wavelength-flexible, very high average power systems with overall efficiencies in the range of 10 to 20%

  11. Investigation into the accuracy of a proposed laser diode based multilateration machine tool calibration system

    International Nuclear Information System (INIS)

    Fletcher, S; Longstaff, A P; Myers, A

    2005-01-01

    Geometric and thermal calibration of CNC machine tools is required in modern machine shops with volumetric accuracy assessment becoming the standard machine tool qualification in many industries. Laser interferometry is a popular method of measuring the errors but this, and other alternatives, tend to be expensive, time consuming or both. This paper investigates the feasibility of using a laser diode based system that capitalises on the low cost nature of the diode to provide multiple laser sources for fast error measurement using multilateration. Laser diode module technology enables improved wavelength stability and spectral linewidth which are important factors for laser interferometry. With more than three laser sources, the set-up process can be greatly simplified while providing flexibility in the location of the laser sources improving the accuracy of the system

  12. Precision improvement of frequency-modulated continuous-wave laser ranging system with two auxiliary interferometers

    Science.gov (United States)

    Shi, Guang; Wang, Wen; Zhang, Fumin

    2018-03-01

    The measurement precision of frequency-modulated continuous-wave (FMCW) laser distance measurement should be proportional to the scanning range of the tunable laser. However, the commercial external cavity diode laser (ECDL) is not an ideal tunable laser source in practical applications. Due to the unavoidable mode hopping and scanning nonlinearity of the ECDL, the measurement precision of FMCW laser distance measurements can be substantially affected. Therefore, an FMCW laser ranging system with two auxiliary interferometers is proposed in this paper. Moreover, to eliminate the effects of ECDL, the frequency-sampling method and mode hopping influence suppression method are employed. Compared with a fringe counting interferometer, this FMCW laser ranging system has a measuring error of ± 20 μm at the distance of 5.8 m.

  13. Early Results of Retrograde Transpopliteal Angioplasty of Iliofemoral Lesions

    International Nuclear Information System (INIS)

    Saha, Saumitra; Gibson, Matthew; Magee, Timothy R.; Galland, Robert B.; Torrie, E. Peter H.

    2001-01-01

    Purpose: To assess whether the retrograde transpopliteal approach is a safe, practical and effective alternative to femoral puncture for percutaneous transluminal angioplasty (PTA).Methods: Forty PTAs in 38 patients were evaluated. Intentional subintimal recanalization was performed in 13 limbs. Ultrasound evaluation of the popliteal fossa was carried out 30 min and 24 hr post procedurally in the first 10 patients to exclude local complications. All patients had a follow-up of at least 6 weeks.Results: The indication for PTA was critical ischemia in seven limbs and disabling claudication in the remainder.Stenoses (single or multiple) were present in 24 and occlusion in 15.The superficial femoral artery (SFA) was the commonest segment affected(36) followed by common femoral artery (CFA) in four and iliac artery in four. Technical success was achieved in 38 of 39 limbs where angioplasty was carried out. In one limb no lesion was found.Immediate complications were distal embolization in two and thrombosis in one. None of these required immediate surgery. There were no puncture site hematomas or popliteal arteriovenous fistulae.Symptomatic patency at 6 weeks was 85%. Further reconstructive surgery was required in three limbs and amputation in two.Conclusion: The transpopliteal approach has a high technical success rate and a low complication rate with a potential to develop into an outpatient procedure. It should be considered for flush SFA occulsions or iliac disease with tandem CFA/SFA disease where the contralateral femoral approach is often technically difficult

  14. XUV free-electron laser-based projection lithography systems

    Energy Technology Data Exchange (ETDEWEB)

    Newnam, B.E.

    1990-01-01

    Free-electron laser sources, driven by rf-linear accelerators, have the potential to operate in the extreme ultraviolet (XUV) spectral range with more than sufficient average power for high-volume projection lithography. For XUV wavelengths from 100 nm to 4 nm, such sources will enable the resolution limit of optical projection lithography to be extended from 0.25 {mu}m to 0.05{mu}m and with an adequate total depth of focus (1 to 2 {mu}m). Recent developments of a photoinjector of very bright electron beams, high-precision magnetic undulators, and ring-resonator cavities raise our confidence that FEL operation below 100 nm is ready for prototype demonstration. We address the motivation for an XUV FEL source for commercial microcircuit production and its integration into a lithographic system, include reflecting reduction masks, reflecting XUV projection optics and alignment systems, and surface-imaging photoresists. 52 refs., 7 figs.

  15. COHERENT LIDAR SYSTEM BASED ON A SEMICONDUCTOR LASER AND AMPLIFIER

    DEFF Research Database (Denmark)

    2009-01-01

    The present invention relates to a compact, reliable and low-cost coherent LIDAR (Light Detection And Ranging) system for remote wind-speed determination, determination of particle concentration, and/or temperature based on an all semiconductor light source and related methods. The present...... invention provides a coherent LIDAR system comprising a semiconductor laser for emission of a measurement beam of electromagnetic radiation directed towards a measurement volume for illumination of particles in the measurement volume, a reference beam generator for generation of a reference beam, a detector...... for generation of a detector signal by mixing of the reference beam with light emitted from the particles in the measurement volume illuminated by the measurement beam, and a signal processor for generating a velocity signal corresponding to the velocity of the particles based on the detector signal....

  16. The precision of today's satellite laser ranging systems

    Science.gov (United States)

    Dunn, Peter J.; Torrence, Mark H.; Hussen, Van S.; Pearlman, Michael R.

    1993-06-01

    Recent improvements in the accuracy of modern satellite laser ranging (SLR) systems are strengthened by the new capability of many instruments to track an increasing number of geodetic satellite targets without significant scheduling conflict. This will allow the refinement of some geophysical parameters, such as solid Earth tidal effects and GM, and the improved temporal resolution of others, such as Earth orientation and station position. Better time resolution for the locations of fixed observatories will allow us to monitor more subtle motions at the stations, and transportable systems will be able to provide indicators of long term trends with shorter occupations. If we are to take advantage of these improvements, care must be taken to preserve the essential accuracy of an increasing volume of range observations at each stage of the data reduction process.

  17. GaN-Based Laser Wireless Power Transfer System

    Directory of Open Access Journals (Sweden)

    Carlo De Santi

    2018-01-01

    Full Text Available The aim of this work is to present a potential application of gallium nitride-based optoelectronic devices. By using a laser diode and a photodetector, we designed and demonstrated a free-space compact and lightweight wireless power transfer system, whose efficiency is limited by the efficiency of the receiver. We analyzed the effect of the electrical load, temperature, partial absorption and optical excitation distribution on the efficiency, by identifying heating and band-filling as the most impactful processes. By comparing the final demonstrator with a commercial RF-based Qi system, we conclude that the efficiency is still low at close range, but is promising in medium to long range applications. Efficiency may not be a limiting factor, since this concept can enable entirely new possibilities and designs, especially relevant for space applications.

  18. Target plane imaging system for the Nova laser

    International Nuclear Information System (INIS)

    Swift, C.D.; Bliss, E.S.; Jones, W.A.; Reeves, R.J.; Seppala, L.G.; Shelton, R.T.; VanArsdall, P.J.

    1985-01-01

    The Nova laser, in operation since December 1984, is capable of irradiating targets with light at 1.05 μm, 0.53 μm, and 0.35 μm. Correct alignment of these harmonic beams uses a system called a target plane imager (TPI). It is a large microscope (four meters long, weighing one thousand kilograms) that relays images from the target chamber center to a video optics module located on the outside of the chamber. Several modes of operation are possible including: near-field viewing and far-field viewing at three magnifications and three wavelengths. In addition, the entire instrument can be scanned in X,Y,Z to examine various planes near chamber center. Performance of this system and its computer controls will be described

  19. Los Alamos free-electron laser (FEL) rf system

    International Nuclear Information System (INIS)

    Tallerico, P.J.; Lynch, M.T.

    1985-01-01

    The FEL rf system was designed for 3.6-MW rf pulses from two klystrons to drive two linacs and one deflection cavity at 1300 MHz. Two 108.33-MHz subharmonic buncher cavities and one fundamental buncher were also built, each powered by a 5-kW amplifier. A single phase-coherent source drives the various amplifiers as well as the grid of the electron gun, which is pulsed at 21.67 MHz. The initial buncher system did not work as well as expected, and the first linac tank required more rf power than anticipated. The light output was extremely sensitive to amplitude and phase errors. More powerful klystrons were developed and installed, and a method was discovered for operating a single subharmonic buncher and allowing the first linac to complete the bunching process. This paper shows the actual configuration used to operate the laser and discusses future improvements

  20. Optical design and development of a fiber coupled high-power diode laser system for laser transmission welding of plastics

    Science.gov (United States)

    Rodríguez-Vidal, Eva; Quintana, Iban; Etxarri, Jon; Azkorbebeitia, Urko; Otaduy, Deitze; González, Francisco; Moreno, Fernando

    2012-12-01

    Laser transmission welding (LTW) of thermoplastics is a direct bonding technique already used in different industrial applications sectors such as automobiles, microfluidics, electronics, and biomedicine. LTW evolves localized heating at the interface of two pieces of plastic to be joined. One of the plastic pieces needs to be optically transparent to the laser radiation whereas the other part has to be absorbent, being that the radiation produced by high power diode lasers is a good alternative for this process. As consequence, a tailored laser system has been designed and developed to obtain high quality weld seams with weld widths between 0.7 and 1.4 mm. The developed laser system consists of two diode laser bars (50 W per bar) coupled into an optical fiber using a nonimaging solution: equalization of the beam parameter product (BPP) in the slow and fast axes by a pair of step-mirrors. The power scaling was carried out by means of a multiplexing polarization technique. The analysis of energy balance and beam quality was performed considering ray tracing simulation (ZEMAX) and experimental validation. The welding experiments were conducted on acrylonitrile/butadiene/styrene (ABS), a thermoplastic frequently used in automotive, electronics and aircraft applications, doped with two different concentrations of carbon nanotubes (0.01% and 0.05% CNTs). Quality of the weld seams on ABS was analyzed in terms of the process parameters (welding speed, laser power and clamping pressure) by visual and optical microscope inspections. Mechanical properties of weld seams were analyzed by mechanical shear tests. High quality weld seams were produced in ABS, revealing the potential of the laser developed in this work for a wide range of plastic welding applications.

  1. Design optimization of single-main-amplifier KrF laser-fusion systems

    International Nuclear Information System (INIS)

    Harris, D.B.; Pendergrass, J.H.

    1985-01-01

    KrF lasers appear to be a very promising laser fusion driver for commercial applications. The Large Amplifier Module for the Aurora Laser System at Los Alamos is the largest KrF laser in the world and is currently operating at 5 kJ with 10 to 15 kJ eventually expected. The next generation system is anticipated to be a single-main-amplifier system that generates approximately 100 kJ. This paper examines the cost and efficiency tradeoffs for a complete single-main-amplifier KrF laser fusion experimental facility. It has been found that a 7% efficient $310/joule complete laser-fusion system is possible by using large amplifier modules and high optical fluences

  2. Laser Tracker Calibration - Testing the Angle Measurement System -

    Energy Technology Data Exchange (ETDEWEB)

    Gassner, Georg; Ruland, Robert; /SLAC

    2008-12-05

    Physics experiments at the SLAC National Accelerator Laboratory (SLAC) usually require high accuracy positioning, e. g. 100 {micro}m over a distance of 150 m or 25 {micro}m in a 10 x 10 x 3 meter volume. Laser tracker measurement systems have become one of the most important tools for achieving these accuracies when mapping components. The accuracy of these measurements is related to the manufacturing tolerances of various individual components, the resolutions of measurement systems, the overall precision of the assembly, and how well imperfections can be modeled. As with theodolites and total stations, one can remove the effects of most assembly and calibration errors by measuring targets in both direct and reverse positions and computing the mean to obtain the result. However, this approach does not compensate for errors originating from the encoder system. In order to improve and gain a better understanding of laser tracker angle measurement tolerances we extended our laboratory's capabilities with the addition of a horizontal angle calibration test stand. This setup is based on the use of a high precision rotary table providing an angular accuracy of better than 0.2 arcsec. Presently, our setup permits only tests of the horizontal angle measurement system. A test stand for vertical angle calibration is under construction. Distance measurements (LECOCQ & FUSS, 2000) are compared to an interferometer bench for distances of up to 32 m. Together both tests provide a better understanding of the instrument and how it should be operated. The observations also provide a reasonable estimate of covariance information of the measurements according to their actual performance for network adjustments.

  3. Laser-assisted skin closure at 1.32 microns: the use of a software-driven medical laser system

    Science.gov (United States)

    Dew, Douglas K.; Hsu, Tung M.; Hsu, Long S.; Halpern, Steven J.; Michaels, Charles E.

    1991-06-01

    This study investigated the use of a computerized 1 .3 micron Nd:YAG laser to seal approximated wound edges in pig skin. The medical laser system used was the DLS Type 1 , 1 .32 micron Nd:YAG laser (Laser Surgery Software, Inc.). The purpose of this study was to evaluate the effectiveness of laser assisted skin closure using the DLS YAG laser in a large animal model. Effectiveness was judged on the basis of wound dehiscence, infection, unusual healing result and consistency of results. Comparative cosmetic result was also evaluated. In this study, the DLS YAG laser was used to close scalpel-induced, full-thickness wounds. The pig model was chosen for its many integumentary similarities to man. Controls included scalpel-induced wounds closed using suture, staple and some with norepair. After adequate anesthesia was achieved, the dorsum of Yucutan pigs (approximately 75- 100 pounds) each was clipped with animal hair clippers from the shoulder area to the hind legs. The area was then shaved with a razor blade, avoiding any inadvertent cuts or abrasions of the skin. The dorsum was divided into four rows of four parallel incisions made by a #15 scalpel blade. Full-thickness incisions, 9 cm long, were placed over the dorsum of the pigs and then closed either with one loosely approximating Prolene" suture (the "no repair' group), multiple interrupted 6-0 nylon sutures, staples or laser. The experimental tissue sealing group consisted of 1 69 laser assisted closures on 1 3 pigs. Sutured control wounds were closed with 6-0 nylon, full thickness, simple, interrupted sutures. Eight sutures were placed 1 cm apart along the 9 cm incision. Stapled control wounds were approximated using two evenly spaced 3-0 VicryP' sub-dermal sutures and the dermis closed using Proximate' skin staples. Eight staples were placed 1 cm apart along the 9 cm incision. The no-repair incisions were grossly approximated using a single 2-0 Prolene full thickness, simple, interrupted suture located at the

  4. Atomic and Molecular Systems in Intense Ultrashort Laser Pulses

    Science.gov (United States)

    Saenz, A.

    2008-07-01

    The full quantum mechanical treatment of atomic and molecular systems exposed to intense laser pulses is a so far unsolved challenge, even for systems as small as molecular hydrogen. Therefore, a number of simplified qualitative and quantitative models have been introduced in order to provide at least some interpretational tools for experimental data. The assessment of these models describing the molecular response is complicated, since a comparison to experiment requires often a number of averages to be performed. This includes in many cases averaging of different orientations of the molecule with respect to the laser field, focal volume effects, etc. Furthermore, the pulse shape and even the peak intensity is experimentally not known with very high precision; considering, e.g., the exponential intensity dependence of the ionization signal. Finally, experiments usually provide only relative yields. As a consequence of all these averagings and uncertainties, it is possible that different models may successfully explain some experimental results or features, although these models disagree substantially, if their predictions are compared before averaging. Therefore, fully quantum-mechanical approaches at least for small atomic and molecular systems are highly desirable and have been developed in our group. This includes efficient codes for solving the time-dependent Schrodinger equation of atomic hydrogen, helium or other effective one- or two-electron atoms as well as for the electronic motion in linear (effective) one-and two-electron diatomic molecules like H_2.Very recently, a code for larger molecular systems that adopts the so-called single-active electron approximation was also successfully implemented and applied. In the first part of this talk popular models describing intense laser-field ionization of atoms and their extensions to molecules are described. Then their validity is discussed on the basis of quantum-mechanical calculations. Finally, some

  5. Intravascular Ultrasound Imaging of Peripheral Arteries as an Adjunct to Balloon Angioplasty and Atherectomy

    International Nuclear Information System (INIS)

    Korogi, Yukunori; Hirai, Toshinori; Takahashi, Mutsumasa

    1996-01-01

    This article reviews many of the applications of intravascular ultrasound (US) imaging for peripheral arterial diseases. In vitro studies demonstrate an excellent correlation between ultrasound measurements of lumen and plaque crossectional area compared with histologic sections. In vivo clinical studies reveal the enhanced diagnostic capabilities of this technology compared with angiography. Intravascular US imaging can provide valuable information on the degree, eccentricity, and histologic type of stenosis before intervention, and on the morphological changes in the arterial wall and the extent of excision after intervention. Intravascular US may also serve as a superior index for gauging the diameter of balloon, stent, laser probe, and/or atherectomy catheter appropriate for a proposed intervention. Significant new insights into the mechanisms of balloon angioplasty and atherectomy have been established by intravascular US findings. Intravascular US imaging has been shown to be a more accurate method than angiography for determining the cross-sectional area of the arterial lumen, and for assessing severity of stenosis. Quantitative assessment of the luminal cross-sectional area after the balloon dilatation should be more accurate than angiography as intimal tears or dissections produced by the dilatation may not be accurately evaluated with angiography. At the present time, intravascular US is still a controversial imaging technique. Outcome studies are currently being organized to assess the clinical value and cost effectiveness of intravascular ultrasound in the context of these interventional procedures

  6. Infrared laser scattering system for the plasma diagnostics: CO/sub 2/ laser characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Hiraki, N; Kawasaki, S; Muraoka, K

    1975-08-01

    A detailed study was conducted of the operating characteristics of a double discharge infrared TEA carbon dioxide laser used for scattering measurements of plasmas. The discharge condition, the laser output energy and power, the beam profile and divergence, the emission spectral line width, the time lag and jitter of the output from the discharge trigger, have been established. It is concluded that the carbon dioxide oscillator can deliver the allowable beam divergence and spectral line width for the measurement of ion temperature in light scattering studies of theta pinch plasmas. The results presented might be applicable to laser fusion experiments using carbon dioxide lasers.

  7. The influence of depression and anxiety in the development of heart failure after coronary angioplasty.

    Science.gov (United States)

    Gegenava, T; Gegenava, M; Kavtaradze, G

    2009-03-01

    The aim of our study was to investigate the association between history of depressive episode and anxiety and complications in patients after 6 months of coronary artery angioplasty. The research was conducted on 70 patients, the grade of coronary occlusion that would not respond to therapeutic treatment and need coronary angioplasty had been established. Complications were estimated in 60 patients after 6 months of coronary angioplasty. To evaluate depression we used Beck depression scale Anxiety was assessed by Spilberger State-trait anxiety scale. Statistic analysis of the data was made by means of the methods of variation statistics using Students' criterion and program of STATISTICA w 5.0. Complications were discovered in 36 (60%) patients; 24 (40%) patients had not complications. There was not revealed significant statistical differences in depression and anxiety degree in coronary angioplasty period and after 6 months of coronary angioplasty. There was not revealed significant statistical differences in depression and anxiety degree in coronary angioplasty period and after 6 months of coronary angioplasty. Our study demonstrated that complications were revealed in patients who had high degree of depression and anxiety.

  8. Percutaneous transluminal angioplasty (PTA) of supra-aortic arteries especially the internal carotid artery

    Energy Technology Data Exchange (ETDEWEB)

    Kachel, R.; Basche, S. (Medizinische Akademie, Erfurt (Germany, F.R.). Radiologische Klinik); Heerklotz, I.; Grossmann, K. (Medizinische Akademie, Erfurt (Germany, F.R.). Klinik fuer Innere Medizin); Endler, S. (Medizinische Akademie, Erfurt (Germany, F.R.). Klinik fuer Neurologie und Psychiatrie)

    1991-06-01

    We present our experience with 105 patients in whom percutaneous transluminal angioplasty was performed in 112 stenosed or occluded supra-aortic arteries. Symtoms of cerebrovascular and/or vertebrobasilar insufficiency were present in 104 of the 105 patients. The angioplasty was successful in 35 stenoses of the internal carotid artery, 2 stenoses of the common carotid artery, 1 stenosis of the external carotid artery, 15 stenoses of the vertebral artery, 3 stenoses of the innominate artery and 44 stenoses of the subclavian artery. There were only 4 minor-complications (2 haematomas, 1 transient ischemic attack, 1 small thrombus of the internal carotid artery which was detected by 111-indium platelet scintigraphy and treated by thrombendarterectomy before the appearance of neurological symptoms). All patients were symptom free after angioplasty. During the observations period of 3 to 109 months (average 58 months) there were only two cases with re-stenosis after subclavian angioplasty. The results of more than 700 personal and international published percutaneous transluminal angioplasties of supra-aortic arteries are presented. The results suggest that angioplasty of supra-aortic arteries is an effective method. On strict definition of the indications, the complication rate for angioplasty of the supra-aortic arteries is not likely to be higher than that for operative treatment. (orig.).

  9. A Multi-Component Automated Laser-Origami System for Cyber-Manufacturing

    Science.gov (United States)

    Ko, Woo-Hyun; Srinivasa, Arun; Kumar, P. R.

    2017-12-01

    Cyber-manufacturing systems can be enhanced by an integrated network architecture that is easily configurable, reliable, and scalable. We consider a cyber-physical system for use in an origami-type laser-based custom manufacturing machine employing folding and cutting of sheet material to manufacture 3D objects. We have developed such a system for use in a laser-based autonomous custom manufacturing machine equipped with real-time sensing and control. The basic elements in the architecture are built around the laser processing machine. They include a sensing system to estimate the state of the workpiece, a control system determining control inputs for a laser system based on the estimated data and user’s job requests, a robotic arm manipulating the workpiece in the work space, and middleware, named Etherware, supporting the communication among the systems. We demonstrate automated 3D laser cutting and bending to fabricate a 3D product as an experimental result.

  10. Laser System for Photoelectron and X-Ray Production in the PLEIADES Compton Light Source

    CERN Document Server

    Gibson, David J; Betts, S; Crane, John; Jovanovic, Igor

    2005-01-01

    The PLEIADES (Picosecond Laser-Electron Interaction for the Dynamic Evaluation of Structures) facility provides tunable short x-ray pulses with energies of 30-140 keV and pulse durations of 0.3 - 5 ps by scattering an intense, ultrashort laser pulse off a 35-75 MeV electron beam. Synchronization of the laser and electron beam is obtained by using a photoinjector gun, and using the same laser system to generate the electrons and the scattering laser. The Ti:Sapphire, chirped pulse amplification based 500 mJ, 50 fs, 810 nm scattering laser and the similar 300 μJ, 5 ps, 266 nm photoinjector laser systems are detailed. Additionally, an optical parametric chirped pulse amplification (OPCPA) system is studied as a replacement for part of the scattering laser front end. Such a change would significantly simplify the set-up the laser system by removing the need for active switching optics, as well as increase the pre-pulse contrast ratio which will be important when part of the scattering laser is used as a...

  11. Obtention of high hardness multilayer systems by laser ablation

    International Nuclear Information System (INIS)

    Mejia T, I.S.

    2007-01-01

    In this thesis work the synthesis of thin films of titanium nitride (TiN), amorphous carbon nitride (CN x ) amorphous carbon (a-C) and Ti/TiN/CNx multilayers and Ti/TiN/a-C by means of the laser ablation technique, with the objective of obtaining films of high hardness is studied, as well as to produce multilayer coatings with superior properties to the individual layers. The effect that has the laser fluence used for ablationing the targets in the structure and mechanical properties of the films deposited of TiN was investigated. It was found that the hardness is increased in lineal way approximately with the fluence increment up to 19 J/cm 2 . Thin films of a-C with hardness of the order of 12 GPa. likewise CN x films with high hardness (18.4 GPa) were obtained. The hardness of the deposited films was analyzed and it was related with its microstructure and deposit conditions. It was concluded that the Ti/TiN/CNx and Ti/TiN/a-C systems presented bigger hardness that of its individual components. (Author)

  12. Endovascular Management of the Popliteal Artery: Comparison of Atherectomy and Angioplasty

    Science.gov (United States)

    Semaan, Elie; Hamburg, Naomi; Nasr, Wael; Shaw, Palma; Eberhardt, Robert; Woodson, Jonathan; Doros, Gheorghe; Rybin, Denis; Farber, Alik

    2013-01-01

    Purpose Symptomatic atherosclerotic disease of the popliteal artery presents challenges for endovascular therapy. We evaluated the technical success, complications and midterm outcomes of atherectomy and angioplasty involving the popliteal segment. Methods We conducted a retrospective review of outcomes of popliteal artery intervention using atherectomy or angioplasty performed between 2003 and 2008. Results A total of 56 patients (36% women, age 72.8±12.2 years, 77% critical limb ischemia) underwent popliteal atherectomy (n=18) or angioplasty (n=38). These patients had similar clinical characteristics, TASC/TASC II classification, mean lesion length, and run-off scores. We observed a trend toward higher rates of technical success defined as atherectomy compared to angioplasty (94% vs. 71%, p=0.08). While angioplasty was associated with a higher frequency of arterial dissection (23% vs. 0%, p=0.003), atherectomy was associated with a higher rate of thromboembolic events (22% vs 0%, p=0.01). Adjunctive stenting was used more frequently following angioplasty compared to atherectomy (45% vs. 6%, p=0.005). Thrombolysis was used to treat embolization in 4 patients in the atherectomy group. The improvement in the ankle-brachial index was similar between the two treatment groups. Primary patency of the popliteal artery at 3, 6, and 12 months was 94%, 88%, and 75% in the atherectomy group and 89%, 82%, and 73% in the angioplasty group (p=NS). There were no significant differences in limb salvage and freedom from reintervention at 1 year between the atherectomy and angioplasty groups. Conclusions Our experience with popliteal artery endovascular therapy indicates a distinct pattern of procedural complications with atherectomy compared to angioplasty but similar midterm patency, limb salvage and freedom from intervention. PMID:19942598

  13. In pursuit of fusion; ARGUS laser system at Livermore

    International Nuclear Information System (INIS)

    Simmons, W.W.

    1976-01-01

    The ARGUS laser facility has been developed to achieve significant laser fusion milestones; high density (greater than 10 g/cm 3 ) implosions, high temperature (greater than 10 KeV) implosions, and high yield from advanced target designs. The ARGUS laser, central to this facility is a twin-beam, 20 cm output aperture, Nd:glass solid state laser capable of delivering greater than 3 TW of power to laser fusion targets. At the present time, ARGUS is fully operational, and has produced up to 10 9 neutrons in selected target irradiation experiments. The performance of this facility is described

  14. Laser induced fragmentation of salivary stones: an in vitro comparison of two different, clinically approved laser systems.

    Science.gov (United States)

    Siedek, Vanessa; Betz, Christian S; Hecht, Volkmar; Blagova, Radka; Vogeser, Michael; Zengel, Pamela; Berghaus, Alexander; Leunig, Andreas; Sroka, Ronald

    2008-04-01

    Clinical laser lithotripsy in urology promises a good fragmentation combined with a minimal risk of soft tissue damage and low medical complications. This in vitro study investigates the fragmentation of salivary stones by means of two clinically used laser systems. The effects induced by the FREDDY laser (WOM, Germany, lambda = 532 nm/1,064 nm, E(pulse) = 120-160 mJ/pulse) and the Ho:YAG (AURIGA, StarMedTec, Germany, lambda = 2,100 nm, E(pulse) = 300-800 mJ/pulse) on clinical salivary calculi (n = 15) and on salivary gland tissue were investigated using clinical laser parameter settings. All experiments were performed in an under water experimental set-up using flexible fibres (core diameter 230 microm) positioned in front of each specimen. In order to assess fragmentation efficacy, each stone was placed on a grating (rhombic mash-diameter 1-3 mm). The fragmentation rate was calculated with respect to the energy applied (mg/J), to the number of pulses (mg/pulse), and to the time needed (mg/minute). In addition the composition of the stones were analysed spectrographically. The soft tissue interaction on human salivary duct mucosa was examined histologically (HE-staining). Spectrographic composition of the salivary stones showed a two component ratio of protein/carbonate apatite varying between 5/95 and 25/75. Stones treated by the Ho:YAG were vaporised in a milling-like process, while using the FREDDY laser stones are cracked into pieces and fragmentation failed in two cases. The fragmentation rates achieved by the FREDDY laser were greater than those of the Ho:YAG laser, but fragments mainly bigger. A dependency on the composition of the stones could not be found. Laser pulse effects on soft tissue were found slightly beyond the mucosa. This study clearly demonstrated the different processes of destroying salivary stones using two different laser systems. While the Ho:YAG vaporises the calculi in a more milling and soft sense, the FREDDY shows a more cracking and

  15. Critical appraisal of paclitaxel balloon angioplasty for femoral–popliteal arterial disease

    Directory of Open Access Journals (Sweden)

    Herten M

    2016-08-01

    Full Text Available Monika Herten,1 Giovanni B Torsello,1,2 Eva Schönefeld,3 Stefan Stahlhoff2 1Department of Vascular and Endovascular Surgery, University Hospital Münster, 2Department of Vascular Surgery, St Franziskus Hospital, Münster, 3Institute for Education and Student Affairs, University Hospital Münster, Münster, Germany Abstract: Peripheral arterial disease, particularly critical limb ischemia, is an area with urgent need for optimized therapies because, to date, vascular interventions often have limited life spans. In spite of initial encouraging technical success after femoropopliteal percutaneous transluminal angioplasty or stenting, postprocedural restenosis remains the major problem. The challenging idea behind the drug-coated balloon (DCB concept is the biological modification of the injury response after balloon dilatation. Antiproliferative drugs administered via DCBs or drug-eluting stents are able to suppress neointimal hyperplasia, the main cause of restenosis. This article reviews the results of DCB treatments of femoropopliteal and infrapopliteal lesions in comparison to standard angioplasty with uncoated balloons. A systematic literature search was performed in 1 medical journals (ie, MEDLINE, 2 international registers for clinical studies (ie, www.clinicaltrials.gov, and 3 abstracts of scientific sessions. Several controlled randomized trials with follow-up periods of up to 5 years demonstrated the efficacy of paclitaxel –DCB technology. However, calcified lesions seem to affect the efficacy of DCB. Combinations of preconditioning methods with DCBs showed promising results. Although the mechanical abrasion of calcium via atherectomy or laser ablation showed favorable periprocedural results, the long-term impact on restenosis and clinical outcome has to be demonstrated. Major advantages of the DCBs are the rapid delivery of drug at uniform concentrations with a single dose, their efficacy in areas wherein stents have been

  16. Atherectomy offers no benefits over balloon angioplasty in tibial interventions for critical limb ischemia.

    Science.gov (United States)

    Todd, Kevin E; Ahanchi, Sadaf S; Maurer, Christian A; Kim, Jung H; Chipman, Candice R; Panneton, Jean M

    2013-10-01

    Endovascular adjuncts, like atherectomy, were developed to improve outcomes of endovascular arterial interventions. The true impact of atherectomy on endovascular outcomes remains to be determined, and little data exist on the influence of atherectomy on tibial interventions. Our study compares early and late outcomes of tibial intervention with angioplasty vs atherectomy-assisted interventions. We completed a retrospective review of all tibial interventions between 2008 and 2010. Outcomes were analyzed using single and multivariate analysis, Cox regression, and Kaplan-Meier curves. Primary outcomes were primary, primary assisted, and secondary patency rates, as well as limb salvage and survival rates. Over a 2-year period, 480 tibial interventions were completed for 421 patients. Eighty-seven percent (n = 418) of interventions were performed for critical limb ischemia (CLI) and 13% (n = 62) for claudication. The CLI cohort of 418 interventions was analyzed. These patients had a mean age of 71 years with a mean follow-up time of 16 ± 15 months (range, 0-59 months). Of the 418 interventions, 339 underwent percutaneous transluminal angioplasty (PTA): 333 PTA alone, six PTA + stent. The remaining 79 interventions received atherectomy: 33 laser, 13 directional, and 33 orbital either alone or in conjunction with PTA (11 atherectomy only, 68 atherectomy + PTA). The groups did not differ significantly in terms of demographics, risk factors, or technical success. The atherectomy group had more TASC B lesions (54% vs 38%; P = .013), while the PTA-alone group had more TASC D lesions (25% vs 13%; P = .004). TASC A and C lesions did not differ significantly between the groups. No significant differences existed with respect to the early (30-day) outcomes of loss of patency (11% vs 13%; P = .699), complications (8% vs 13%; P = .292), or major amputation (17% vs 13%; P = .344) in the PTA-alone group vs the atherectomy-assisted group. Kaplan-Meier analysis revealed no difference

  17. Optimization of an Optical Parametric Chirped Pulse Amplification System for the OMEGA EP Laser System

    International Nuclear Information System (INIS)

    Begishev, I.; Bagnoud, V.; Guardalben, M.; Waxer, L.; Puth, J.; Zuegel, J.

    2003-01-01

    OAK B204 We report on the experimental achievements of the optical parametric chirped-pulse amplification (OPCPA) system, including 29% pump-to-signal conversion efficiency and 107 gain using two LBO crystals configured as a single amplification stage. Temporal and spatial shaping of the pump laser pulse is required to achieve both high-gain and high-conversion efficiency

  18. A new design of pulsed laser diode driver system for multistate quantum key distribution

    Science.gov (United States)

    Abdullah, M. S.; Jamaludin, M. Z.; Witjaksono, G.; Mokhtar, M. H. H.

    2011-07-01

    In this paper, we describe a new design of laser diode driver system based on MOSFET current mirror and digital signal controller (DSC). The system is designed to emit stream pairs of photons from three semiconductor laser diodes. The DSC is able to switch between the three laser diodes at constant rate. The duty cycle is maintained at 1% in order to reduce its thermal effect and thus prolong the laser diodes' life cycles. The MOSFET current mirror circuits are capable of delivering constant modulation current with peak current up to 58 mA to each laser diode. This laser driver system will allow the generating biphotons automatically with qubit rate around 8-13% for μ less than or equal to 1, thus making it practical for six-states quantum key distribution implementation.

  19. Diode-pumped, single frequency Nd:YLF laser for 60-beam OMEGA laser pulse-shaping system

    International Nuclear Information System (INIS)

    Okishev, A.V.; Seka, W.

    1997-01-01

    The operational conditions of the OMEGA pulse-shaping system require an extremely reliable and low-maintenance master oscillator. The authors have developed a diode-pumped, single-frequency, pulsed Nd:YLF laser for this application. The laser generates Q-switched pulses of ∼160-ns duration and ∼10-microJ energy content at the 1,053-nm wavelength with low amplitude fluctuations (<0.6% rms) and low temporal jitter (<7 ns rms). Amplitude and frequency feedback stabilization systems have been used for high long-term amplitude and frequency stability

  20. Percutaneous balloon angioplasty for the treatment of iliofemoral arterial stenosis resulting from hyperhomocysteinemia in a child

    Energy Technology Data Exchange (ETDEWEB)

    Maynar, Manuel; Lopez-Benitez, Ruben [Diagnostic and Therapeutic Endoluminal Unit, Hospiten Rambla, Tenerife (Spain); Kirsch, David S.; Qian, Zhong [Department of Radiology, Louisiana State University Health Science Center, 1542 Tulane Avenue, LA 70112-2822, New Orleans (United States); Gomez-Sirvent, Jorge [Department of Pediatrics, Hospiten Rambla, Tenerife (Spain); Zerolo-Saez, Ignacio [Department of Surgery, Hospiten Rambla, Tenerife (Spain)

    2003-08-01

    Angioplasty has long been used in the treatment of peripheral arterial occlusive disease with variable long-term results. In this case report, we present a patient with marfanoid features and acute ischemia of the lower extremity. Angioplasty provided us with the means of emergently relieving the acute symptoms. The patient was subsequently found on further work-up to have hyperhomocysteinemia (HC) and appropriate medical therapy was initiated. We conclude that angioplasty should be considered in pediatric patients with acute occlusive limb ischemia, providing excellent immediate results to preserve the limb as well as the time to investigate the underlying causes. (orig.)

  1. Percutaneous balloon angioplasty for the treatment of iliofemoral arterial stenosis resulting from hyperhomocysteinemia in a child

    International Nuclear Information System (INIS)

    Maynar, Manuel; Lopez-Benitez, Ruben; Kirsch, David S.; Qian, Zhong; Gomez-Sirvent, Jorge; Zerolo-Saez, Ignacio

    2003-01-01

    Angioplasty has long been used in the treatment of peripheral arterial occlusive disease with variable long-term results. In this case report, we present a patient with marfanoid features and acute ischemia of the lower extremity. Angioplasty provided us with the means of emergently relieving the acute symptoms. The patient was subsequently found on further work-up to have hyperhomocysteinemia (HC) and appropriate medical therapy was initiated. We conclude that angioplasty should be considered in pediatric patients with acute occlusive limb ischemia, providing excellent immediate results to preserve the limb as well as the time to investigate the underlying causes. (orig.)

  2. Upgrading NASA/DOSE laser ranging system control computers

    Science.gov (United States)

    Ricklefs, Randall L.; Cheek, Jack; Seery, Paul J.; Emenheiser, Kenneth S.; Hanrahan, William P., III; Mcgarry, Jan F.

    1993-01-01

    Laser ranging systems now managed by the NASA Dynamics of the Solid Earth (DOSE) and operated by the Bendix Field Engineering Corporation, the University of Hawaii, and the University of Texas have produced a wealth on interdisciplinary scientific data over the last three decades. Despite upgrades to the most of the ranging station subsystems, the control computers remain a mix of 1970's vintage minicomputers. These encompass a wide range of vendors, operating systems, and languages, making hardware and software support increasingly difficult. Current technology allows replacement of controller computers at a relatively low cost while maintaining excellent processing power and a friendly operating environment. The new controller systems are now being designed using IBM-PC-compatible 80486-based microcomputers, a real-time Unix operating system (LynxOS), and X-windows/Motif IB, and serial interfaces have been chosen. This design supports minimizing short and long term costs by relying on proven standards for both hardware and software components. Currently, the project is in the design and prototyping stage with the first systems targeted for production in mid-1993.

  3. Applying dual-laser spot positions measurement technology on a two-dimensional tracking measurement system

    International Nuclear Information System (INIS)

    Lee, Hau-Wei; Chen, Chieh-Li

    2009-01-01

    This paper presents a two-dimensional tracking measurement system with a tracking module, which consists of two stepping motors, two laser diodes and a four separated active areas segmented position sensitive detector (PSD). The PSD was placed on a two-dimensional moving stage and used as a tracking target. The two laser diodes in the tracking module were directly rotated to keep the laser spots on the origin of the PSD. The two-dimensional position of the target PSD on the moving stage is determined from the distance between the two motors and the tracking angles of the two laser diodes, which are rotated by the two stepping motors, respectively. In order to separate the four positional values of the two laser spots on one PSD, the laser diodes were modulated by two distinct frequencies. Multiple-laser spot position measurement technology was used to separate the four positional values of the two laser spots on the PSD. The experimental results show that the steady-state voltage shift rate is about 0.2% and dynamic cross-talk rate is smaller than 2% when the two laser spots are projected on one PSD at the same time. The measurement errors of the x and y axial positions of the two-dimensional tracking system were less than 1% in the measuring range of 20 mm. The results demonstrate that multiple-laser spot position measurement technology can be employed in a two-dimensional tracking measurement system

  4. The ARGOS laser system: green light for ground layer adaptive optics at the LBT

    Science.gov (United States)

    Raab, Walfried; Rabien, Sebastian; Gässler, Wolfgang; Esposito, Simone; Barl, Lothar; Borelli, Jose; Daysenroth, Matthias; Gemperlein, Hans; Kulas, Martin; Ziegleder, Julian

    2014-07-01

    We report on the development of the laser system of ARGOS, the multiple laser guide star adaptive optics system for the Large Binocular Telescope (LBT). The system uses a total of six high powered, pulsed Nd:YAG lasers frequency-doubled to a wavelength of 532 nm to generate a set of three guide stars above each of the LBT telescopes. The position of each of the LGS constellations on sky as well as the relative position of the individual laser guide stars within this constellation is controlled by a set of steerable mirrors and a fast tip-tilt mirror within the laser system. The entire opto-mechanical system is housed in two hermetically sealed and thermally controlled enclosures on the SX and DX side of the LBT telescope. The laser beams are propagated through two refractive launch telescopes which focus the beams at an altitude of 12 km, creating a constellation of laser guide stars around a 4 arcminute diameter circle by means of Rayleigh scattering. In addition to the GLAO Rayleigh beacon system, ARGOS has also been designed for a possible future upgrade with a hybrid sodium laser - Rayleigh beacon combination, enabling diffraction limited operation. The ARGOS laser system was successfully installed at the LBT in April 2013. Extensive functional tests have been carried out and have verified the operation of the systems according to specifications. The alignment of the laser system with respect to the launch telescope was carried out during two more runs in June and October 2013, followed by the first propagation of laser light on sky in November 2013.

  5. Development of a Fibre-Phased Array Laser-EMAT Ultrasonic System for Defect Inspection

    International Nuclear Information System (INIS)

    Pei, C; Demachi, K; Koyama, K; Uesaka, M; Fukuchi, T; Chen, Z

    2014-01-01

    In this work, a phased array laser ultrasound system with using fibre optic delivery and a custom-designed focusing objective lens has been developed for enhancing the ultrasound generation. The fibre-phased array method is applied to improve the sensitivity and detecting ability of the laser-EMAT system for defect inspection

  6. A vision-based system for fast and accurate laser scanning in robot-assisted phonomicrosurgery.

    Science.gov (United States)

    Dagnino, Giulio; Mattos, Leonardo S; Caldwell, Darwin G

    2015-02-01

    Surgical quality in phonomicrosurgery can be improved by open-loop laser control (e.g., high-speed scanning capabilities) with a robust and accurate closed-loop visual servoing systems. A new vision-based system for laser scanning control during robot-assisted phonomicrosurgery was developed and tested. Laser scanning was accomplished with a dual control strategy, which adds a vision-based trajectory correction phase to a fast open-loop laser controller. The system is designed to eliminate open-loop aiming errors caused by system calibration limitations and by the unpredictable topology of real targets. Evaluation of the new system was performed using CO(2) laser cutting trials on artificial targets and ex-vivo tissue. This system produced accuracy values corresponding to pixel resolution even when smoke created by the laser-target interaction clutters the camera view. In realistic test scenarios, trajectory following RMS errors were reduced by almost 80 % with respect to open-loop system performances, reaching mean error values around 30 μ m and maximum observed errors in the order of 60 μ m. A new vision-based laser microsurgical control system was shown to be effective and promising with significant positive potential impact on the safety and quality of laser microsurgeries.

  7. Exploding pusher targets for the SHIVA laser system

    International Nuclear Information System (INIS)

    Rosen, M.D.; Larsen, J.T.; Nuckolls, J.H.

    1977-01-01

    The first targets for the 20 TW SHIVA laser system were designed. They are simple glass micro-balloons, approximately 300 μm in diameter and 2 μm thick, filled with D-T gas. Using LASNEX, whose model physics was utilized successfully for ARGUS targets, we optimize for both gain and yield. The target behaves as an exploding pusher. Different simple analytic models for the physics of this mode are presented, and are tested by comparing their scaling predictions, at constant absorbed power, with those demonstrated by LASNEX. Emphasis is placed on successful prediction of the basic quantities of peak ion temperature and compression, rather than neutron yield or n tau

  8. Diffraction measurements for LASL's Antares Laser System. Informal report

    International Nuclear Information System (INIS)

    Sollid, J.E.

    1978-08-01

    Beam diffraction, both in the near field and the far field, was studied to assess the effect of the 12-segmented annular exit window proposed for the Antares laser system. The near-field studies indicate that diffraction spillover effects are less than 5% and that hot spots in the aperture are not apt to exceed the design flux level of 2 J/cm 2 . The far-field investigation has shown that the segments in the annulus may be considered independently and, therefore, energy and intensity add up incoherently. Also, the total intensity distribution is well approximated by 12 times the intensity distribution in a circular aperture with the same area as a single sector

  9. Comparison of orbital atherectomy plus balloon angioplasty vs. balloon angioplasty alone in patients with critical limb ischemia: results of the CALCIUM 360 randomized pilot trial.

    Science.gov (United States)

    Shammas, Nicolas W; Lam, Russell; Mustapha, Jihad; Ellichman, Jonathan; Aggarwala, Gaurav; Rivera, Ernesto; Niazi, Khusrow; Balar, Nilesh

    2012-08-01

    To evaluate the role of orbital atherectomy in calcified infrapopliteal arteries in patients with critical limb ischemia compared to balloon angioplasty (BA) alone. A randomized multicenter study was undertaken to evaluate short and 1-year outcomes in 50 patients (32 men; mean age 71 years, range 40-90) with confirmed calcified lesions using 1∶1 randomization to the Diamondback 360° Orbital Atherectomy System followed by BA vs. BA alone. All patients had severe (≥50% stenosis) peripheral artery disease (Rutherford classification 4-6) in the popliteal, tibial, and/or peroneal arteries. The primary endpoint was defined as restoration of a normal lumen (residual stenosis ≤30%) with no bailout stenting or dissection types C through F. Scheduled follow-up visits were conducted according to a common protocol at 1, 6, and 12 months. Procedural success was 93.1% (27/29 lesions) for atherectomy + BA patients and 82.4% (28/34 lesions) for BA alone (p = 0.27). Bailout stenting was needed in 2 (6.9%) of the 29 atherectomy + BA lesions and in 5 (14.3%) of the 35 BA-treated lesions (p = 0.44). At 1 year, there were no amputations in either group related to the index procedure. Estimates for freedom from target vessel revascularization and all-cause mortality were 93.3% and 100% in the atherectomy + BA group vs. 80.0% (p = 0.14) and 68.4% (p = 0.01) in the BA group, respectively. Proportional hazard models evaluating survival time vs. status of residual stenosis determined a hazard ratio for major adverse events of 5.6 for patients with an acute post-procedure residual stenosis >30% (p = 0.01). Debulking with orbital atherectomy appeared to increase the chance of reaching a desirable angioplasty result, with less acute need for bailout stenting and a higher procedure success. A negative association between procedure success and risk of serious adverse outcomes should encourage larger confirmatory studies.

  10. Combined Directional Atherectomy and Drug-Eluting Balloon Angioplasty for Isolated Popliteal Artery Lesions in Patients With Peripheral Artery Disease.

    Science.gov (United States)

    Stavroulakis, Konstantinos; Bisdas, Theodosios; Torsello, Giovanni; Stachmann, Arne; Schwindt, Arne

    2015-12-01

    To evaluate the midterm results of combined directional atherectomy (DA) and drug-eluting balloon (DEB) angioplasty for atherosclerotic lesions of the popliteal artery. In a single-arm, prospective study, 21 patients (mean age 63±16 years; 16 men) with isolated popliteal artery lesions were enrolled and underwent treatment with combined DA and DEB angioplasty under filter protection between October 2009 and February 2014. The majority (18, 86%) presented with lifestyle-limiting intermittent claudication and 3 with critical limb ischemia. Fifteen (71%) target sites were de novo lesions; 4 were occlusions. The main outcome was primary patency; secondary outcomes were technical success, secondary patency, and early and midterm morbidity and mortality. The TurboHawk atherectomy device was used in 15 (71%) patients and the SilverHawk peripheral plaque excision system in the remaining 6 patients. The In.Pact Admiral/Pacific DEB was used in the majority of cases (15, 71%). The technical success rate was 90% (n=19). One flow-limiting dissection was treated with bailout stenting. Complications included a perforation of the popliteal artery and 2 puncture site hematomas; there was no distal embolic event. The mean follow-up was 18±12 months. Two restenoses were retreated successfully. Kaplan-Meier estimates of primary patency at 12 and 18 months were 95% and 90%, respectively; the secondary patency was 100%. One (5%) patient died in follow-up. None of the patients had an amputation. In this prospective single-arm study, the combined therapy of DA and DEB angioplasty for popliteal artery lesions showed promising midterm performance. The combination of DA and DEB may, in highly selected patients, overcome the challenges presented by the mobility of the knee joint. © The Author(s) 2015.

  11. Approach to compact terawatt CO2 laser system for particle acceleration

    International Nuclear Information System (INIS)

    Pogorelsky, I.V.; Kimura, W.D.; Fisher, C.H.; Kannari, F.

    1994-01-01

    A compact table-top 20-GW 50-ps CO 2 laser system is in operation for strong-field physics studies at the ATF. We propose scaling up of the picosecond CO 2 laser to a terawatt peak power level to meet the requirements of advanced laser accelerators. Computer modeling shows that a relatively compact single-beam picosecond CO 2 laser system with a high-pressure x-ray picosecond amplifier of a 10-cm aperture is potentially scalable to the ∼1-TW peak power level

  12. The Laboratory for Laser Energetics’ Hydrogen Isotope Separation System

    Energy Technology Data Exchange (ETDEWEB)

    Shmayda, W.T., E-mail: wshm@lle.rochester.edu; Wittman, M.D.; Earley, R.F.; Reid, J.L.; Redden, N.P.

    2016-11-01

    The University of Rochester’s Laboratory for Laser Energetics has commissioned a hydrogen Isotope Separation System (ISS). The ISS uses two columns—palladium on kieselguhr and molecular sieve—that act in a complementary manner to separate the hydrogen species by mass. The 4-sL per day throughput system is compact and has no moving parts. The columns and the attendant gas storage and handling subsystems are housed in a 0.8 -m{sup 3} glovebox. The glovebox uses a helium cover gas that is continuously processed to extract oxygen and water vapor that permeates through the glovebox gloves and any tritium that is released while attaching or detaching vessels to add feedstock to or drawing product from the system. The isotopic separation process is automated and does not require manual intervention. A total of 315 TBq of tritium was extracted from 23.6 sL of hydrogen with tritium purities reaching 99.5%. Deuterium was the sole residual component in the processed gas. Raffinate contained 0.2 TBq of activity was captured for reprocessing. The total emission from the system to the environment was 0.4 GBq over three weeks.

  13. Development of surgical CW Nd:YAG laser with optical fiber delivery system

    International Nuclear Information System (INIS)

    Kim, Cheol Jung; Kim, Jeong Mook; Jung, Chin Mann; Kim, Kwang Suk; Kim, Min Suk; Cho, Jae Wan; Kim, Duk Hyun

    1992-06-01

    We developed a surgical CW Nd:YAG laser with optical fiber delivery system. Several commercial models have been investigated in design and performance. We improved its quality to the level of commercial Nd:YAG laser by an endurance test for each parts of laser system. The maximum power of our surgical laser was 150 W and the laser pulse width could be controlled to 99 sec continuously by 0.1 sec. Many optical parts were localized and lowered much in cost. Only few parts were imported and almost 90% in cost were localized. Also, to find out the maintenance problem of this surgical laser, it was applicated to the production line of our joint company. (Author)

  14. Intensity Noise Transfer Through a Diode-pumped Titanium Sapphire Laser System

    DEFF Research Database (Denmark)

    Tawfieq, Mahmoud; Hansen, Anders Kragh; Jensen, Ole Bjarlin

    2017-01-01

    higher RIN than a setup with only a single nonlinear crystal. The Ti:S is shown to have a cut-off frequency around 500 kHz, which means that noise structures of the pump laser above this frequency are strongly suppressed. Finally, the majority of the Ti:S noise seems to originate from the laser itself......In this paper, we investigate the noise performance and transfer in a titanium sapphire (Ti:S) laser system. This system consists of a DBR tapered diode laser, which is frequency doubled in two cascaded nonlinear crystals and used to pump the Ti:S laser oscillator. This investigation includes...... electrical noise characterizations of the utilized power supplies, the optical noise of the fundamental light, the second harmonic light, and finally the optical noise of the femtosecond pulses emitted by the Ti:S laser. Noise features originating from the electric power supply are evident throughout...

  15. Study on improvement of laser system performance for uranium isotope separation

    International Nuclear Information System (INIS)

    Fujii, Takashi

    1998-01-01

    For the purpose of reducing the cost of Atomic Vapor Laser Isotope Separation (AVLIS), I developed the following laser technologies. (1) I developed a solid-state pulse power supply, of which output power was the almost highest value achieved for a copper vapor laser in 1989, using a GTO as a switching device and a magnetic pulse compression circuit. (2) I developed a new technique of tuning the laser wavelength to an atomic absorption band using high-speed wavelength shift of a laser diode by direct modulation. (3) I developed a new technique of stabilizing the laser wavelength at an absorption band of a target atom, by locking the sideband generated by phase modulation of a laser beam to a Fabry-Perot interferometer. (4) I proposed the Cr 4+ -doped forsterite laser system as an all solid-state laser system for the AVLIS. I obtained the slope efficiency of 25%, which was the highest value achieved in the case of pulse operation of the Cr 4+ -doped forsterite laser in 1995, using the forsterite with high Cr 4+ -ion concentration. (author)

  16. The development of laser surgery and medicine in China

    Science.gov (United States)

    Chen, Mingzhe

    2005-07-01

    The first Chinese ruby laser was created in 1961 and it was adopted for the retina coagulation experiment in 1965. Since 1970's, lasers had been widely applied clinically including the diseases suitable to physical therapy or acupuncture. The Chinese HpD was first produced in 1981 and first case of PDT was treated using Chinese HpD and Chinese lasers in the same year. Its success brought attention establishing a research group supported by the government in 1982. A nationwide systemic research project on PDT was then carried out. The step taken for PDT also accelerated the development of various fields of laser medicine and surgery. Laser treatments had been commonly adopted in the clinics and hospitals for the diseases of the superficial lesions and the lesions can be reached by the endoscopes non-invasively in 1980's. Since 1990's, the interventional laser therapies adopted mainly were percutaneous laser angioplasty, laser treatments through laparoscope, thoracoscope, arthroscope, neuro-endoscope etc. Ultrasound guided percutaneous laser heat coagulation for small hepatic cancer revealed good results and ultrasound guided percutaneous PDT for advanced large liver cancer revealed unexpected results after five years follow-up. At present: There are more long-term follow-up patients in the clinical trial; more advanced commercial available lasers and new techniques are adopted. Since the popularization of scanning electron microscope, laser scanning confocal microscope, laser induced auto-fluorescence system, high sensitivity fluorescence microscopic imaging system etc. in the laboratories, the basic studies can be more advanced and some times, the sub-cellular level can be reached; ultra-structure histo-morphology and gene studies are involved. In dermatology, Q-switched Alexandrite laser and other Q-switched lasers are used mainly for the treatment of skin pigmentation and vascular diseases; pulsed dye laser, ultra-pulsed CO2 laser are used in resurfacing, facial

  17. Interferometric investigation of an early stage of plasma expansion with the high-power laser system PALS

    Czech Academy of Sciences Publication Activity Database

    Kasperczuk, A.; Pisarczyk, P.; Pisarczyk, T.; Králiková, Božena; Mašek, Karel; Pfeifer, Miroslav; Rohlena, Karel; Skála, Jiří; Ullschmied, Jiří; Kálal, M.

    2002-01-01

    Roč. 52, č. 3 (2002), s. 395-404 ISSN 0011-4626 R&D Projects: GA MŠk LN00A100 Institutional research plan: CEZ:AV0Z2043910 Keywords : laser plasma, PALS laser system, laser interferometry Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.311, year: 2002

  18. Transluminal coronary angioplasty (TCA) techniques, indications and results

    International Nuclear Information System (INIS)

    Kober, G.; Lang, H.; Vallbracht, C.; Bussmann, W.D.; Hopf, R.; Kunkel, B.; Kaltenbach, M.

    1985-01-01

    Transluminal coronary angioplasty (TCA) was introduced in 1977 for dilatation of coronary stenoses. From October 1977 to December 1984 1087 procedures have been performed in Frankfurt. The mean success rate was 77% with an increase from 58% to 84% since 1977. Recurrences were seen within the first year in 15% of the patients, which could be treated successfully in a high percentage with a second TCA. Emergency bypass operations were necessary in 5.2%. Four patients (fatality rate 0.37%) died as the consequence of the intervention. Within few years TCA has become an established procedure for myocardial revascularisation, with a high success rate. Major progress has been possible in the last few years due to technical developments, which are still going on. They may lead to further improvement of the results and enlargement of the indication for TCA. (orig.) [de

  19. The copper-pumped dye laser system at Lawrence Livermore National Laboratory

    International Nuclear Information System (INIS)

    Hackel, R.P.; Warner, B.E.

    1993-01-01

    The Lawrence Livermore National Laboratory's (LLNL) Atomic Vapor Laser Isotope Separation (AVLIS) Program has developed a high-average-power, pulsed, tunable, visible laser system. Testing of this hardware is in progress at industrial scale. The LLNL copper-dye laser system is prototypical of a basic module of a uranium-AVLIS plant. The laser demonstration facility (LDF) system consists of copper vapor lasers arranged in oscillator-amplifier chains providing optical pump power to dye-laser master-oscillator-power-amplifier chains. This system is capable of thousands of watts (average) tunable between 550 and 650 mm. The copper laser system at LLNL consists of 12 chains operating continuously. The copper lasers operate at nominally 4.4 kHz, with 50 ns pulse widths and produce 20 W at near the diffraction limit from oscillators and >250 W from each amplifier. Chains consist of an oscillator and three amplifiers and produce >750 W average, with availabilities >95% (i.e., >8,300 h/y). The total copper laser system power averages ∼9,000 W and has operated at over 10,000 W for extended intervals. The 12 copper laser beams are multiplexed and delivered to the dye laser system where they pump multiple dye laser chains. Each dye chain consists of a master oscillator and three or four power amplifiers. The master oscillator operates at nominally 100 mW with a 50 MHz single mode bandwidth. Amplifiers are designed to efficiently amplify the dye beam with low ASE content and high optical quality. Sustained dye chain powers are up to 1,400 W with dye conversion efficiency >50%, ASE content <5%, and wavefront quality correctable to <λ/10 RMS, using deformable mirrors. Since the timing of the copper laser chains can be offset, the dye laser system is capable of repetition rates which are multiples of 4.4 kHz, up to 26 kHz, limited by the dye pumping system. Development of plant-scale copper and dye laser hardware is progressing in off-line facilities

  20. Current trends in laser fusion driver and beam combination laser system using stimulated Brillouin scattering phase conjugate mirrors for a fusion driver

    International Nuclear Information System (INIS)

    Kong, Hong Jin

    2008-01-01

    Laser fusion energy (LFE) is well known as one of the promising sources if clean energy for mankind. Laser fusion researches have been actively progressed, since Japan and the Soviet Union as well as USA developed ultrahigh power lasers at the beginning of 1970s. At present in USA, NIF (National Ignition Facility), which is the largest laser fusion facility in the world, is under construction and will be completed in 2008. Japan as a leader of the laser fusion research has developed a high energy and high power laser system, Gekko XII, and is under contemplation of FIREX projects for the fast ignition. China also has SG I, II lasers for performing the fusion research, and SG III is under construction as a next step. France is also constructing LMJ (Laser countries, many other developed countries in Europe, such as Russia, Germany, UK, and so on, have their own high energy laser systems for the fusion research. In Korea, the high power laser development started with SinMyung laser in KAIST in 1994, and KLF (KAERI Laser Facility) of KAERI was recently completed in 2007. For the practical use of laser fusion energy, the laser driver should be operated with a high repetition rate around 10Hz. Yet, current high energy laser systems, Such as NIF, Gekko XII, and etc., can be operated with only several shots per day. Some researchers have developed their own techniques to reduce the thermal loads of the laser material, by using laser diodes as pump sources and ceramic laser materials with high thermal energy scaling up for the real fusion driver. For this reason, H. J. Kong et al. proposed the beam combination laser system using stimulated Brillouin scattering phase conjugate mirrors (SBS PCMs) for a fusion driver. Proposed beam combination has many advantages for energy scaling up; it is composed by simple optical systems with small amount of components, there is no interaction between neighbored sub beams, the SBS PCMs can be used for a high energy beam reflection with