Conference on Lasers and Electro-Optics Europe最新文献_第10页

Epitaxial Pr,Yb:LiYF4 Waveguides for Upconversion Lasers 上转换激光器的外延Pr,Yb:LiYF4波导

Conference on Lasers and Electro-Optics Europe Pub Date : 1998-01-01 DOI: 10.1364/cleo_europe.1998.cthf6

P. Rogin, G. Huber

{"title":"Epitaxial Pr,Yb:LiYF4 Waveguides for Upconversion Lasers","authors":"P. Rogin, G. Huber","doi":"10.1364/cleo_europe.1998.cthf6","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cthf6","url":null,"abstract":"Upconversion lasers based on lanthanide doped host materials have been known for several years. The efficiency of their multiphoton excitation schemes depends critically on the absence of competing nonradiative processes, depleting the intermediate energy levels involved as well as the upper laser level. For this reason, fluoride host materials generally outperform oxides due to their lower phonon energies and, consequently, lower multiphonon relaxation rates. In this work, we concentrate on LiYF4 (YLF) codoped with Pr3+ and Yb3+, allowing for a sensitized avalanche upconversion mechanism [1] to produce red (639.5 nm) output upon pumping at ~ 835 nm. The threshold pump intensity of this process is in the order of 105 to 106 W/cm2, requiring a tightly focused pump beam. In bulk media, the high divergency of such a beam results in a very short gain medium, where only a small part of the incident light is absorbed, giving rise to a poor overall efficiency. A longer gain medium, as demonstrated with fluoride glass fibres, allows for a far better performance. In a disordered host material, however, the inhomogeneous broadening of the spectral lines reduces the peak gain cross section. Therefore, it seems promising to combine the advantages of the fibre geometry and a crystalline host by using crystalline waveguides.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80491067","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}

引用次数: 0

Phase conjugation in CO2 laser medium: theory and experiment CO2激光介质中的相位共轭:理论与实验

Conference on Lasers and Electro-Optics Europe Pub Date : 1998-01-01 DOI: 10.1364/cleo_europe.1998.cthn5

A. Ionin, A. Kotkov, A. P. Napartovich, L. Seleznev, P. A. Svotin

{"title":"Phase conjugation in CO2 laser medium: theory and experiment","authors":"A. Ionin, A. Kotkov, A. P. Napartovich, L. Seleznev, P. A. Svotin","doi":"10.1364/cleo_europe.1998.cthn5","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cthn5","url":null,"abstract":"Phase conjugation (PC) processes at degenerate four-wave mixing (DFWM) in the active medium of a pulsed e-beam controlled discharge CO2-laser were studied both experimentally and theoretically. The experiment was carried out with the following parameters: laser gas mixture CO2:N2:He=1:2:4, gas pressure 0.3 bar, active medium length 1.2 m, resonator length 12 m (17.7 m for single line laser), interaction angle ~10 mrad at DFWM without optical delay between probe wave and co-propagating pump one. Integral PC reflectivity (PCR) strongly depends on such parameters as: specific input energy (Fig. 1); intensity ratio for probe J3 and co-propagating pump J1 wave (Fig.2); coherency of the laser radiation, that varied by rotation of mutual polarization or with optical delay between probe wave and co-propagating pump one; geometry of DFWM; output mirror reflectance Rout (8-80%) (PCR was maximum with Rout of 8% but best quality of PC signal was observed with Rout =80%); gas mixture composition and pressure, being maximum for a mixture with a low fraction of helium and at higher pressure (up to 0.6 bar). A periodical dependence of PCR on optical delay between probe and co-propagating pump wave with periods 10−3 and 10−5 m was observed. The PCR did not depend on spectral content and a degree of linear polarization of the laser radiation.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80169229","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}

引用次数: 0

Continuous-wave diode-pumped Nd3+: YAG ceramics laser 连续波二极管泵浦Nd3+: YAG陶瓷激光器

Conference on Lasers and Electro-Optics Europe Pub Date : 1998-01-01 DOI: 10.1364/cleo_europe.1998.cwf17

K. Yoshida, T. Taira, A. Ikesue

引用次数: 0

Self-mode-locked semiconductor laser in a ring cavity 环形腔内自锁模半导体激光器

Conference on Lasers and Electro-Optics Europe Pub Date : 1998-01-01 DOI: 10.1364/cleo_europe.1998.cpd1.3

P. Langlois, M. Piché

{"title":"Self-mode-locked semiconductor laser in a ring cavity","authors":"P. Langlois, M. Piché","doi":"10.1364/cleo_europe.1998.cpd1.3","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cpd1.3","url":null,"abstract":"We report on the generation of short (2 ps) pulses directly from a self-mode-locked semiconductor amplifier inserted in a ring cavity. The amplifier is in fact a superluminescent diode consisting of a 500 mm long double quantum-well InGaAlAs ridge waveguide with strained InGaAs active layers ; an angled stripe geometry provides a low coherence emission with a broad spectrum centered near 855 nm. The amplifier is placed in a ring cavity with three gold minors and a 83% transmission output coupler. Collimation of the laser output and careful alignment of the cavity mirrors allows laser emission with a threshold bias current Ith near 46 mA. Self-mode locking is achieved when the dc bias current is set at ~1.2 Ith, and when the cavity is slightly misaligned. Figures 1 and 2 show typical non-colinear autocorrelation traces and optical spectra of the pulses circulating in the clockwise (cw) and counterclockwise (ccw) directions. The counterpropagating pulses have similar temporal profiles with durations from 2 to 6 ps (after deconvolution) and characterized by a weak pedestal that falls to zero. Remarkably, the pulse respective optical spectra are different, as the spectrum of the ccw pulse has a 2.9 nm bandwidth peaked at 864 nm, whereas that of the cw pulse is peaked near 867 nm with a bandwidth of 0.9 nm. Both circulating pulses have a time-bandwidth product exceeding several times the Fourier-transformed limit, which suggests that they can be compressed to subpicosecond durations.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"75 2-3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78138595","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}

引用次数: 0

Progress in Chemical Oxygen-Iodine Lasers 化学氧碘激光器的研究进展

Conference on Lasers and Electro-Optics Europe Pub Date : 1998-01-01 DOI: 10.1364/cleo_europe.1998.cthe1

K. Truesdell

引用次数: 0

Excited-state dynamics and energy transfer processes involved in the 1.5 and 2.3µm laser transitions in Yb:Tm doped LiYF4 and KY3F10 single crystals Yb:Tm掺杂LiYF4和KY3F10单晶中1.5和2.3µm激光跃迁的激发态动力学和能量转移过程

Conference on Lasers and Electro-Optics Europe Pub Date : 1998-01-01 DOI: 10.1364/cleo_europe.1998.ctuk2

A. Braud, S. Girard, J. Doualan, R. Moncorgé, M. Diaf, M. Thuau

{"title":"Excited-state dynamics and energy transfer processes involved in the 1.5 and 2.3µm laser transitions in Yb:Tm doped LiYF4 and KY3F10 single crystals","authors":"A. Braud, S. Girard, J. Doualan, R. Moncorgé, M. Diaf, M. Thuau","doi":"10.1364/cleo_europe.1998.ctuk2","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.ctuk2","url":null,"abstract":"Tm doped fluoride crystals sensitized with Yb ions were early recognized as very efficient upconversion laser materials for visible room temperature operation under infrared excitation. Recently, the advantage of ytterbium as codopant was pointed out to enhance the 1.5µm emission 3H4→3F4 and to avoid the bottlenecking effect on this laser transition[1]. In order to determine several energy-transfer parameters involved in the excitation processes of Yb-Tm doped laser materials, samples of Tm:Yb:LiYF4 and Tm:Yb:KY3F10 with different dopant concentrations were grown by Czochralski technique, oriented and cut. Energy transfer processes and upconversion effects in Tm:Yb codoped fluoride crystals were quantitatively studied with classical energy transfer models (direct dipole-dipole interaction - Förster-Dexter model extended by Inokuti-Hirayama and migration assisted energy transfer - Yokota-Tanimoto or Burshtein models), using absorption, emission and excited-state absorption cross sections experimental data as input parameters. The results were systematically compared, in the case of fast energy migration, with those deduced from the adjustement between the rate equation model and the measured kinetics of the excited state levels of the Yb (2F5/2) and Tm (3F4,3H4, 1G4 and 1D2) ions. Both decay times after short pulse excitation and rise times after square-pulse shape excitation on the Yb ions were investigated to obtain a complete description of the excitation scheme for the Tm upper energy levels.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85531921","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}

引用次数: 0

Single-pass distortion correction using innovative holographic methods in rhodium-doped barium titanate 利用创新的全息方法在掺铑钛酸钡中进行单次畸变校正

Conference on Lasers and Electro-Optics Europe Pub Date : 1998-01-01 DOI: 10.1364/cleo_europe.1998.cpd2.4

L. Corner, M. Damzen

引用次数: 0

TEA CO2 dial station for atmospheric water and pollutants measurements 用于大气水和污染物测量的TEA CO2拨号站

Conference on Lasers and Electro-Optics Europe Pub Date : 1998-01-01 DOI: 10.1364/cleo_europe.1998.ctui84

C. Bellecci, P. Gaudio, M. Valentini, S. Martellucci, P. Aversa, G. Caputi, F. De Donato R. Zoccali

引用次数: 0

Photorefractive Effect in Copper-Doped LiNbO3 Waveguides 掺铜LiNbO3波导的光折变效应

Conference on Lasers and Electro-Optics Europe Pub Date : 1998-01-01 DOI: 10.1364/cleo_europe.1998.cthh56

S. Kostritskii, P. Moretti

{"title":"Photorefractive Effect in Copper-Doped LiNbO3 Waveguides","authors":"S. Kostritskii, P. Moretti","doi":"10.1364/cleo_europe.1998.cthh56","DOIUrl":"https://doi.org/10.1364/cleo_europe.1998.cthh56","url":null,"abstract":"Photorefractive waveguides (PRW) are of prime interest for applications in integrated optics such as optical switching, resonant filtering or holographic memories. Therefore, investigations are to date extensively increasing to search new efficient methods of PRW’s fabrication Among the potential optical materials, lithium niobate (LiNbO3) has been subjected to extensive development, especially because crystals of good optical quality are commercially available. Comparatively to other known and mostly used methods of PRW’s elaboration in LiNbO3, the very new method of combined proton and copper exchange seems to present some interesting advantages [1,2]. This ionic exchange process enables to control easily and precisely the photorefractive response parameters since the copper concentration as well as the ratio Cu+/Cu2+ can be varied gradually in a wide range [1]. Moreover, it allows to reach an extremely high holographic sensitivity [2]. However, an undesired feature of the proton-exchanged waveguides is that the electrooptical coefficients are reduced significantly [2]. In contrast, no degradation of the latter is observed in ion-implanted waveguides [3]. Therefore, to elaborate the LiNbO3 waveguides with improved photorefractive properties, we have used a new two-step techique : First, the optical waveguides are formed by implantation of He+-ions at room temperature under a fluence of 2×1016 ions/cm2 and with an energy of 1 MeV, and second, the photorefractive sensitivity of the waveguides are increased by using the combined proton and copper exchage process, but conducted in specific conditions, i.e. when the proton exchange is minima, not sufficient to induce both an essential degradation of the electrooptical effect and a marked change of the effective refractive index.","PeriodicalId":10610,"journal":{"name":"Conference on Lasers and Electro-Optics Europe","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"1998-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84227255","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}

引用次数: 0

Nonlinear Optical Properties of Czochralski-Grown Periodically Poled LiNbO3 Crystals czochralski生长周期极化LiNbO3晶体的非线性光学性质

Conference on Lasers and Electro-Optics Europe Pub Date : 1998-01-01 DOI: 10.1364/cleo_europe.1998.ctua7

O. Gliko, I. Naumova, J. Ju, H. K. Kim, M. Cha

引用次数: 0