Advanced High-Power Lasers and Applications最新文献

{"title":"New concept: fiber embedded disk and tube lasers","authors":"H. Sekiguchi, G. Vienne, Akiyoshi Tanaka, Yukari Senda, Katsuhisa Ito, Y. Matsuoka, H. Toratani, Shirō Takahashi, H. Miyajima, H. Kan, K. Ueda","doi":"10.1117/12.380876","DOIUrl":"https://doi.org/10.1117/12.380876","url":null,"abstract":"We present a new concept to scale up the power of fiber lasers into the kW range and report on the first laser based on this concept: a 'fiber embedded tube laser.' An optical to optical slope efficiency of 28% and a laser output power exceeding 10 W were easily achieved.","PeriodicalId":375593,"journal":{"name":"Advanced High-Power Lasers and Applications","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121631852","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"100-W-average-power Nd:YAG laser with adaptive cavity formed by self-induced population gratings","authors":"O. Antipov, A. Kuzhelev, D. Chausov, A. Zinoviev, A. Fedin, A. Gavrilov, S. Smetanin","doi":"10.1117/12.380945","DOIUrl":"https://doi.org/10.1117/12.380945","url":null,"abstract":"We report the experimental and numerical investigation of a self-starting Nd:YAG laser oscillator with cavity completed by population gratings which are induced in the laser crystal by generating beams themselves. The spatio-temporal characteristics of the laser including three Nd:YAG amplifiers and the saturable absorber (LiF:F2- or Cr4+:YAG) have been investigated. The laser oscillator with a nonlinear mirror has displayed self-adaptivity to strong thermally induced intracavity distortions. The generation of single mode beams with an average power of as large as 100 W and near-diffraction limited quality has been achieved.","PeriodicalId":375593,"journal":{"name":"Advanced High-Power Lasers and Applications","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114703219","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Optical quality of NCLR's 1-kW 1-kHz XeCl excimer laser","authors":"R. M. Hofstra, J. Timmermans, Hubert J. G. Van Heel","doi":"10.1117/12.380908","DOIUrl":"https://doi.org/10.1117/12.380908","url":null,"abstract":"The optical quality of NCLR's 1 kW, 1 kHz XeCl excimer laser has been investigated. Nearly diffraction limited beams can be obtained in short burst mode up to 1 kHz. Long burst mode operation is currently limited by the quality of the optics. The beam pointing variation is reduced to half the divergence angle and is found to be independent of the repetition rate of the laser system.","PeriodicalId":375593,"journal":{"name":"Advanced High-Power Lasers and Applications","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127603483","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling high-power semiconductor lasers: from microscopic physics to device applications","authors":"J. Moloney, M. Kolesik, J. Hader, S. Koch","doi":"10.1117/12.380861","DOIUrl":"https://doi.org/10.1117/12.380861","url":null,"abstract":"A robust, modular and comprehensive simulation model, built on a first-principles microscopic physics basis, includes the fully time-dependent and spatially resolved internal optical, carrier and temperature fields within an arbitrary geometry edge-emitting high-power semiconductor laser device. The simulator is designed to run interactively on a multi- processor shared memory graphical supercomputer by utilizing a highly efficient algorithm running in parallel over multiple CPUs. The experimentally validated semiconductor optical response is computed using a microscopic approach that includes the relevant bandstructure of the Quantum Well and confining barrier regions together with a fully quantum mechanical many-body calculation that takes all occupied bands into account. The latter quantity is introduced into the simulator via a multidimensional look-up table that captures the local dependence of the gain and refractive index of the structure over a broad range of frequencies and carrier densities. The simulator is designed in a modular form so as to be able to include differing device geometries (broad area, flared, multiple contacts, arrays, ..), filters (DBR or DFB grating sections), index/gain-guiding, temperature and current profiles and so on. Results will be presented for both broad area and MOPA devices.","PeriodicalId":375593,"journal":{"name":"Advanced High-Power Lasers and Applications","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131273136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"8-W highly efficient Yb-doped fiber laser","authors":"V. Reichel, S. Unger, V. Hagemann, H. Mueller, M. Auerbach","doi":"10.1117/12.380877","DOIUrl":"https://doi.org/10.1117/12.380877","url":null,"abstract":"In this paper a very compact device of a very efficient high- power fiber-laser based on a specially designed Ytterbium (Yb)-doped double-clad D-Shape silica fiber with an output power of more than 8 watts will be described. The development, preparation and characterization of rare-earth doped double- clad optical fibers based on silica for the application in high-power fiber-lasers were done at the Optics Division of the Institute for Physical High-Technology e.V. Jena (IPHT) in the last few years. The doping with Ytterbium as the laseractive component was one of the most important questions which were investigated. Many samples had to be made for the optimum concentration of Yb, the optimum codoping and geometry, respectively. As a result of these experiments we realized a double-clad fiber with D-shape geometry of the pump-core. This D-shape resulted from ray-tracing calculations performed at the Lasercentre Hannover e.V. (LZH) as an optimal solution for the high conversion efficiency of the pump-power. Considering these numerical results, such fibers were realized at IPHT by drawing a sidepolished preform by preserving the cross section of the preform. After some basic investigations on the optimum wavelength for the pump-light and the resonator length, respectively, a compact device with a launched pump- power of approx. 13 W and an output-power of more than 8 watts was developed and realized. The maximum output-power was only limited by the pump-power available at our laboratory at the chosen wavelength. Main advantages of the setup are the short length of the laseractive fiber (less than 10 m), the high efficiency (greater than 60%) and the compactness of the device. Additionally, the diameter of the pump-core was reduced to 125 micrometer. These kinds of fibers were tested with a specially designed pump-source of the Fraunhofer Institute for Applied Optics and Precision Engineering in Jena. The first result with a double-clad Yb-doped fiber of only 4 meter length was a fiber-laser with an output-power of about 4 Watts. Last but not least, some basic experiments with Fiber-Bragg-Gratings (FBG) as one of the resonator mirrors were done. A fiber-laser with a FBG for the laser-wavelength had an output-power of about 700 mW with a FWHM of about 0.1 nm.","PeriodicalId":375593,"journal":{"name":"Advanced High-Power Lasers and Applications","volume":"103 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115086199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Directly obtaining a giant quasi-single picosecond pulse by efficient ISHG","authors":"Feng-tie Wu","doi":"10.1117/12.380926","DOIUrl":"https://doi.org/10.1117/12.380926","url":null,"abstract":"Intracavity frequency doubling with (beta) -BaB2O4 (BBO) crystal in a passively mode-locked unstable confocal resonator Nd:YAP (Nd:YALO3) pulsed laser is described. Without any amplification and pulse selection, a powerful quasi-single psec pulse at 0.54 micrometer with an energy greater than 20 mJ and power density 5 GW/cm2 was obtained by totally passive mode locking for the first time. Energy conversion efficiency 81% from 1.08 to 0.54 micrometer was achieved. The technique of intracavity second harmonic generation (ISHG) leads to stable output energy of SHG with an energy stability of 95.96%. This has a higher stability than that of fundamental wave with an energy stability of 92.78%.","PeriodicalId":375593,"journal":{"name":"Advanced High-Power Lasers and Applications","volume":"116 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121900797","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improvement of surface laser damage resistance in CsLiB6O10 crystal for high-power UV lasers","authors":"T. Kamimura, K. Nakai, M. Yoshimura, Y. Mori, T. Sasaki, Y. Okada, H. Yoshida, M. Nakatsuka, T. Kojima, K. Yoshida","doi":"10.1117/12.380917","DOIUrl":"https://doi.org/10.1117/12.380917","url":null,"abstract":"Effect of ion beam etching on surface damage resistance was investigated in CsLiB6O10(CLBO) crystal. In high-power UV operation, an as-polished CLBO surface was damaged due to absorption of the polishing compound embedded inside the crystal surface. In the as-polished surface of CLBO, polishing compound ZrO2 (absorption edge is about 300 nm) was detected to a depth of 60 nm. We have removed polishing compound with ion beam etching without degrading the surface quality. The effects of polishing compound removal on surface damage were characterized for the surface laser-induced damage threshold (LIDT) at 355 nm (pulse width 0.85 ns) as a function of etching depth and surface lifetime for the generation of fourth-harmonic of ND:YAG laser (266 nm, 20 ns, 4 kHz). We found an improvement of the surface damage resistance. LIDT of etched surface increased up to 15 J/cm2 as compared with that of the as-polished surface of 11 J/cm2. Etched CLBO surface also exhibits an improvement lifetime 4 times longer than that of as-polished surface.","PeriodicalId":375593,"journal":{"name":"Advanced High-Power Lasers and Applications","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121912370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"200-W InGaAlAs/GaAs diode laser bars for pumping","authors":"B. Acklin, M. Behringer, G. Herrmann, J. Luft, C. Hanke, L. Korte, M. Marchiano, J. Wilhelmi, B. De Odorico","doi":"10.1117/12.380872","DOIUrl":"https://doi.org/10.1117/12.380872","url":null,"abstract":"Solid state laser pumping is an important application for high power semiconductor lasers. The higher electro-optical conversion efficiency (50%), and narrower spectral emission (2 - 5 nm) of laser diodes allow for more efficient pumping compared to flash lamps, and consequently lead to superior thermal and optical properties of the solid state laser. A further performance increase and thus price reduction, especially for pulsed and qcw operation, is conceivable using a promising approach proposed almost 20 years ago which we dubbed 'micro-stack lasers.' It consists in vertically integrating multiple active laser junctions in one -- structure using degenerately doped tunnel junctions to electrically connect the intermediate reverse junctions. By stacking 2 to 4 emitters in this way, the output power of semiconductor lasers could theoretically be increased by a factor of 2 to 4 as the reliable output power is mainly limited by the power density at the laser facets. Modern growth technology can provide the necessary 10 to 20 micrometer thick high quality epitaxial layers. The limiting factors rather originate from the additional electrical and thermal resistance, and from current spreading towards the deeper junctions.","PeriodicalId":375593,"journal":{"name":"Advanced High-Power Lasers and Applications","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129593882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Compact free-electron lasers exploiting media with periodically modulated refractive index","authors":"V. Apollonov, A. Artemyev, M. Fedorov, E. Shapiro, J. McIver","doi":"10.1117/12.380900","DOIUrl":"https://doi.org/10.1117/12.380900","url":null,"abstract":"Amplification in free-electron lasers exploiting media with periodically modulated refractive indices is studied in the regime of a large modulation. The conditions for realization of the large-modulation regime in a layered plasma medium and in a periodic dielectric superlattice-like medium are established. The maximized gain, the corresponding saturation field and efficiency, as well as the optimal electron energy and propagation direction are determined and compared to each other for different types of modulated media. It is shown that the large-modulation regime makes it possible to extend significantly the operation frequency domain of the FEL employing a low-relativistic electron beam. Relationship with the Cherenkov and stimulated resonance-transition-radiation FELs is discussed.","PeriodicalId":375593,"journal":{"name":"Advanced High-Power Lasers and Applications","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127840619","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Thermo-optic dispersion formula of KNbO3 for mid-infrared OPO","authors":"N. Umemura, K. Yoshida, K. Katō","doi":"10.1117/12.380918","DOIUrl":"https://doi.org/10.1117/12.380918","url":null,"abstract":"The improved Sellmeier's equations and thermo-optic dispersion formula that reproduce well our experimental results for harmonic generation of CO2 laser harmonics at 3.5303 - 5.2955 micrometers are presented. These formulas are believed to be highly useful for predicting the temperature-tuned 90 degree(s) phase-matched OPO in the mid-infrared.","PeriodicalId":375593,"journal":{"name":"Advanced High-Power Lasers and Applications","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123235671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}