1994 Conference on Lasers and Electro-Optics Europe最新文献

{"title":"Nearly-ideal Au/Pt-n-(p+n-) AI0.48ln0.52As Schottky contacts with a barrier height of 1.09 eV for high-speed photodetectors and transistors","authors":"G. Stareev, A. Fricke, D. Sowada, T. Kummetz, J. Mähnss, W. Kowalsky, K. Ebeling","doi":"10.1364/cleo_europe.1994.cwf37","DOIUrl":"https://doi.org/10.1364/cleo_europe.1994.cwf37","url":null,"abstract":"During the last years significant efforts have been made to increase the Schottky barrier height in various InP devices such as high-speed photodetectors and transistors. Chu et al.1 found that the barrier height ϕBn of contacts to n-type InAlAs is independent of the choice of the metal and given by ϕBn = 0.61 eV. Oppositely, Sadwick et al.2 observed a pronounced influence of the kind of the metal on the barrier height with a highest ϕBn. value of 0.72 eV for Pt contacts. Such data dispersing imply that the treatment of the semiconductor surface is of primary importance. We demonstrate that the quality of Au/Pt-n-AlInAs Schottky barrier diodes can be improved, if low energy (30 eV) Ar+ bombardment for 1 min prior to the metal evaporation and proper rapid thermal processing (RTP) for 20 s are used. Experiments were performed onto 1.5 µm-thick Si-doped AlInAs layers with a donor concentration of 2 × 1016cm−3 grown by MBE. Some wafers were subjected to shallow (20 nm) Zn diffusion. Pt/Au Schottky contacts with diameters of 500 µm were fabricated in a procedure similar to the method described elsewhere.3 Figure 1 presents barrier heights of Au/Pt-n-AlInAs contacts as-deposited and after subsequent RTP at temperatures ranging from 230 to 430°C. Prior to any heat treatment the chemically cleaned and ion-etched contacts exhibit barrier heights of ϕBn = 0.82 eV and ϕBn = 0.85 eV, respectively. The annealing has no significant effect on ϕBn if the surface is only chemically precleaned, but gives a drastic enhancement of ϕBn for ion-etched diodes. The highest value of ϕBn = 1.09 eV is obtained with RTP carried out at 400°C. In our opinion, this is the largest ever reported value of ϕBn for AlInAs. The distinguished increase of ϕBn is due to the formation of a thin interfacial PtAs2 layer,4 which results from thermally stimulated As outdiffusion towards the metal. This subtle reaction is obviously suppressed by native oxides in chemically precleaned samples. The ion process used introduces negligible subsurface damages since the starting ϕBn values for chemically and ion-cleaned wafers are similar.","PeriodicalId":276336,"journal":{"name":"1994 Conference on Lasers and Electro-Optics Europe","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114842651","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":"1.55-μm room temperature laser action of Cr4+:Y3Al5O12 and Cr4+:Y3Sc0.9Al4.1O12","authors":"S. Kück, K. Petermann, G. Huber","doi":"10.1364/cleo_europe.1994.cthn4","DOIUrl":"https://doi.org/10.1364/cleo_europe.1994.cthn4","url":null,"abstract":"Tunable solid-state lasers based on transition metal ions have a wide range of applications in the field of ranging, remote sensing, medicine, optical communication, and scientific research. Especially the spectral region around 1.55 μm is interesting, because of the second window of the transmission of fibres for optical communication. In this paper laser action at 1.55 μm of Cr4+:Y3Al5O12 and Cr4+:Y3Sc0.9Al4.1O12 crystals is presented.","PeriodicalId":276336,"journal":{"name":"1994 Conference on Lasers and Electro-Optics Europe","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117077254","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":"GalnAsSb injection lasers operating near 2.1µm up to 130°C","authors":"A. Baranov, C. Fouillant, G. Boissier, P. Grech, S. Gaillard, C. Alibert, A. Joullie","doi":"10.1364/cleo_europe.1994.ctuk22","DOIUrl":"https://doi.org/10.1364/cleo_europe.1994.ctuk22","url":null,"abstract":"Laser diodes operating at wavelengths around 2µm are useful for applications such as molecular spectroscopy, \"eye safe\" communication sources, and pumps for the Ho-YAG solid-state laser system. Lasers with structures containing a GalnAsSb active region and AlGaAsSb confining layers have shown good performance in the 1.8–2.5µm wavelength domain.1-3 In this communication we present double heterostructure (DH) lasers operating at temperatures up to Tmax = 130°C, which is the highest maximum temperature reported to date for conventional DH lasers emitting at more than 2 µm.","PeriodicalId":276336,"journal":{"name":"1994 Conference on Lasers and Electro-Optics Europe","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117291506","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":"On the feasibility of 1.5 µm laser emission in concentrated Er systems","authors":"V. Lupei, S. Georgescu, S. Grecu","doi":"10.1364/cleo_europe.1994.ctuk80","DOIUrl":"https://doi.org/10.1364/cleo_europe.1994.ctuk80","url":null,"abstract":"Laser emission in the 1.5-1.6 µm range is important for fiber optic communications. A major candidate as an active ion is Er3+, whose emission from the first excited level falls in this region. Since at high Er concentrations an efficient up-conversion (with rate P1) takes place, depopulating the emitting level (4I13/2), only very diluted Er systems were considered.","PeriodicalId":276336,"journal":{"name":"1994 Conference on Lasers and Electro-Optics Europe","volume":"144 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116379781","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":"A pulsed CO2 laser to process high damage threshold materials","authors":"I. Watson, C. Chatwin, D. Mcdonald, Brain F. Scott","doi":"10.1364/cleo_europe.1994.cml7","DOIUrl":"https://doi.org/10.1364/cleo_europe.1994.cml7","url":null,"abstract":"Pulsed CO2 lasers with suitable output characteristics can efficiently process high reflectivity and/or refractory materials. Following a combined simulation and experimental research programme on both the laser and the interaction process, a transversely excited, high PRF, CO2 laser was constructed.1,2 Fig. 1 shows the pumping circuit configuration. To enter the highly absorbing interaction regime, an incident flux intensity of 1011W m-2 is required with a pulse duration between 6–8µs and, to avoid the deleterious melt-freeze process of conventional pulse modulated CW sources, a pulse repetition frequency (PRF) of 5–10 kHz is necessary. The specific energy density of the pumping medium to generate such optical pulses is approximately 12 J 1-1atmosphere-1. Consequently, the gas discharge operates in a substantially different regime to that of TEA lasers, and instabilities due to gas shock wave effects are reduced. Conventional trigger wires were utilised to generate an auxiliary preionising discharge to form stable, uniform glow discharges in a 3-litre cavity over a range of operating conditions, i.e., gas pressure and mixture composition. Analysis of the spatio-temporal development of the electron gain indicates that owing to the low applied E/N the discharge breaks down via the Townsend mechanism. A gas circulation system convectively clears the heated gas from the discharge region. Experimental results are presented for the maximum PRFs achieved with this simple technique of preionisation both with planar-planar electrodes using different laser cavity flow shaping designs (Fig. 3) and for a prototype segmented, ballasted cathode (Fig. 4). Large, gain-switched spikes in the laser output pulse generate intensities sufficiently high to form a plasma above the workpiece. Excessive plasma growth decouples the beam from the workpiece, severely degrading the efficiency of the interaction process. Consequently, the magnitude of the gain-switched spike must be controlled. This can be achieved by optimising the design parameters of the optical resonator and the composition of the laser gas mixture.3 Results are presented that clearly demonstrate the effect of the gas composition on the spike power relative to the total power in the laser output pulse (Fig. 5).","PeriodicalId":276336,"journal":{"name":"1994 Conference on Lasers and Electro-Optics Europe","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122051853","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":"Multiwaveguide CO2 laser with diffractive coupled channels","authors":"K. Abramski, E. E. Plinski, J. Witkowski, R. Nowicki","doi":"10.1364/cleo_europe.1994.ctuk43","DOIUrl":"https://doi.org/10.1364/cleo_europe.1994.ctuk43","url":null,"abstract":"The constructions of high power RF excited waveguide lasers based on multichannel arrays usually require investigations of the cross-coupling between the laser beams in the array.1,2 We built two structures of a ten-channel RF excited CO2 waveguide laser array. Each laser was 400 mm long (380 mm of active length) with the cross-section of 2.2 × 2.2 mm of an individual channel and 0.5 mm thick sidewalls. The first structure was an uncoupled array whereas the second one was diffractive coupled. The maximum output power of the uncoupled array was 250 W at the pressure of 105 Torr. We applied a simple and useful optical arrangement with an external diffraction grating (153 lines/mm) for the simultaneous observation of an array laser spectrum. The laser beams spread on the grating were observed as a dot matrix at a phosphor image screen in a re-imaged near field. Manual and 2-D PZT mirror tuning and tilting enabled us to align all laser beams into the same matrix row corresponding to the separate spectral line. The lasers in the array operated at the few strongest P- or R-branch transitions of the 10.4µm band. A pattern of the transitions was easily identified by above arrangement.","PeriodicalId":276336,"journal":{"name":"1994 Conference on Lasers and Electro-Optics Europe","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127222778","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":"Lifetime measurements in annealed proton exchanged Nd:LiTaO3 waveguide","authors":"S. Nouh, P. Baldi, M. De Micheli, G. Monnom, D. Ostrowsky, E. Lallier, M. Papuchon","doi":"10.1364/cleo_europe.1994.cmm4","DOIUrl":"https://doi.org/10.1364/cleo_europe.1994.cmm4","url":null,"abstract":"Following the recent success in fabricating laser devices in rare-earth-doped lithium niobate,1 it appeared interesting to develop similar elements in rare-earth -doped lithium tantalate in view of this latter material's reputation for having a considerably higher optical damage threshold. Unfortunately, first attempt,2 using proton exchanged waveguides on Nd:LiTaO3 was not very successful due to a reduction of the 4F3/2 excited state lifetime of Nd3+. In order to understand this phenomena and improve the laser performance, we monitored the lifetime as a function of the proton concentration, which was varied by successive annealing.","PeriodicalId":276336,"journal":{"name":"1994 Conference on Lasers and Electro-Optics Europe","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129091595","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":"New geometry for quasi-phase-matched frequency conversion in lithium niobate with periodic domain structure","authors":"A. L. Aleksandrovsky","doi":"10.1364/cleo_europe.1994.cwf98","DOIUrl":"https://doi.org/10.1364/cleo_europe.1994.cwf98","url":null,"abstract":"Quasi-phase-matched concept of frequency conversion was introduced for collinear geometry, with pump propagating normal to layers in periodic structures. Some useful deviations from this case were pointed out recently.1 Here an alternative geometry is proposed: with pump propagating nearly along the layers.","PeriodicalId":276336,"journal":{"name":"1994 Conference on Lasers and Electro-Optics Europe","volume":"1989 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130773581","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":"Third-order optical nonlinearities in ZnCdSe/ZnSSe multiple quantum well","authors":"I. Tanahashi, Y. Manabe, S. Hayashi, M. Yoshida, T. Mitsuyu","doi":"10.1364/cleo_europe.1994.ctum2","DOIUrl":"https://doi.org/10.1364/cleo_europe.1994.ctum2","url":null,"abstract":"MQWs with II-VI compound semiconductors such as ZnSe/ZnS, ZnTe/ZnSe, and CdSe/ZnSe are promising materials for optoelectronic devices.1 Because of a large exciton binding energy due to a small exciton Bohr radius of II-VI compound semiconductors,2 the stable exciton peak can be seen at room temperature in II-VI MQWs. These MQWs have the potential to show large optical nonlinearities. Here, we report on the characterization and third-order nonlinear optical properties of ZnCdSe/ZnSSe MQW fabricated by MBE.","PeriodicalId":276336,"journal":{"name":"1994 Conference on Lasers and Electro-Optics Europe","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127614974","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":"All-solid-state diode-pumped cw femtosecond Cr:LiSrAlF6 lasers","authors":"R. Mellish, S. Hyde, N. Barry, P. French, J. Taylor, P. Delfyett, L. Florez","doi":"10.1007/978-3-642-85176-6_53","DOIUrl":"https://doi.org/10.1007/978-3-642-85176-6_53","url":null,"abstract":"","PeriodicalId":276336,"journal":{"name":"1994 Conference on Lasers and Electro-Optics Europe","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129176198","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}