2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)最新文献

{"title":"Interband transitions in InP biased with THz fields of 4 MV/cm","authors":"C. Schmidt, O. Schubert, F. Junginger, S. Mahrlein, B. Mayer, A. Sell, R. Huber, A. Leitenstorfer","doi":"10.1109/CLEOE.2011.5943525","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943525","url":null,"abstract":"The influence of strong electric fields on electronic properties of semiconductors is of particular interest both for fundamental science and applications in high speed electronics. Investigations using large quasi-static [1] and THz [2] fields have been performed. However, the accessible field amplitudes have been limited to values typically below 1 MV/cm due to the dielectric breakdown under stationary bias and the availability of intense phase-stable THz sources, respectively.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":"9 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78595394","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":"Mid-infrared continuously tunable single mode VECSEL","authors":"A. Khiar, F. Felder, M. Rahim, M. Fill, F. Hobrecker, H. Zogg","doi":"10.1109/CLEOE.2011.5942576","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942576","url":null,"abstract":"Single mode continuously tunable mid-infrared Vertical External Cavity Surface Emitting Lasers (VECSEL) have been realized [1]. IV–VI semiconductors such as PbTe are used for the active region. Emission wavelength is ∼5 µm with a total tuning range >100 nm. The VECSEL is optically pumped using a 1.55 µm laser diode.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":"15 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78726081","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":"Fluorescence properties of thick shell CdSe/CdS quantum dots at cryogenic temperature","authors":"G. Camps, S. Buil, X. Quélin, C. Javaux, B. Mahler, B. Dubertret, J. Hermier","doi":"10.1109/CLEOE.2011.5943586","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943586","url":null,"abstract":"The blinking of fluorophore, that means the switch between bright and dark states, is a well-known phenomenon for single emitters. In the case of standard CdSe/ZnS colloidal quantum dots (QDs), this was considered as their main drawback for experiments at the single molecule level. Statistical analysis of these intensity fluctuations has demonstrated that the dark states duration exhibits a universal heavy-tailed power law distribution. Long off-periods, of the order of the time experiment, are always observed.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":"15 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75133796","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":"High power Tm:silica fiber lasers: Current status, prospects and challenges","authors":"P. Moulton","doi":"10.1109/CLEOE.2011.5943428","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943428","url":null,"abstract":"Reported near-diffraction-limited, cw power levels from Tm-doped silica fiber lasers in the 2000-nm wavelength region have now passed the 1 kW level, due to advances in fiber technology, pump lasers and associated pump-coupling fiber optics. Compared to the more common high-power Yb-doped fibers, Tm:silica fibers have several advantages, particularly with respect to limits set by fiber nonlinear effects such as stimulated Brillouin scattering. These have been exploited to allow generation of 600 W of single-frequency, narrow-linewidth power, the most, to our knowledge, of any fiber-based laser. In addition, there have been significant advances in generation of high-peak-power pulses from Tm:fiber-based sources.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":"42 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76510478","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":"Time-resolved ultrafast all-optical switching in directional couplers with second-order nonlinearity","authors":"A. Solntsev, D. Neshev, R. Schiek","doi":"10.1109/CLEOE.2011.5942650","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942650","url":null,"abstract":"Nonlinear directional couplers (NLDC) allow for ultrafast all-optical switching. To date, various types of NLDCs have been studied, predominantly based on the Kerr [1] or cascaded quadratic nonlinearity [2] in second-harmonic generation (SHG). In the later case the switching can occur at lower powers because of a propagating-wave resonance effect. While a number of experiments to characterise the pulse propagation in Kerr-type couplers exist, till now the temporal behavior of short pulses in the NLDC with quadratic nonlinearity has never been studied experimentally. Several important questions such as the reason for incomplete switching and possible pulse compression factors remain unanswered. In this work we experimentally measure the pulse reshaping in a NLDC with second-order nonlinearity and show that pulse compression, break-up and back-switching play an important role in the switching process.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":"9 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76579594","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":"Dual wavelength and switchable laser operation of Pr3+:LiYF4 crystals at 523 nm and 640 nm","authors":"S. Mũller, N. Hansen, O. Hellmig, K. Petermann, G. Huber","doi":"10.1109/CLEOE.2011.5942436","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942436","url":null,"abstract":"Solid state lasers in the visible spectral region have many possible applications like projection technology and spectroscopy [1,2]. In these fields the generation of green light is still a challenge. Recent projection devices generate green laser light by frequency doubling of near-infrared solid state laser radiation. A compact, simple, and efficient laser based projection device is not yet developed. The trivalent Pr3+ ion in the host material LiYF4 (YLF) has several transitions at wavelengths in the visible spectral range, for example at 523 nm (green) or at 640 nm (red). Pr:YLF can be efficiently pumped by GaInN laser diodes at 444 nm (blue) [3].","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":"21 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77592530","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":"Singlemode tunable VCSELs with integrated MEMS technology","authors":"B. Kogel, P. Debernardi, P. Westbergh, Å. Haglund, J. Gustavsson, J. Bengtsson, E. Haglund, A. Larsson","doi":"10.1109/CLEOE.2011.5942587","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942587","url":null,"abstract":"A simple MEMS technology for wafer-scale integration of tunable VCSELs is presented in Fig. 1 a) [1]. The tunableVCSEL is composed of a “half-VCSEL”, which is a VCSEL without top distributed Bragg reflector (DBR), and an externalmirror, which is a micromachined membrane (“MEMS”). The GaAs-based half-VCSEL comprises a bottom DBR, an active region with 5 quantum wells (QWs), and an oxide aperture for current confinement. The etched mesa is capped with an antireflection coating (AR-c) and embedded in a low-k dielectric (BCB). Reflown photo-resist droplets are used as sacrificial layer and as preform for making curved micro-mirrors, as shown in Fig. 1 b). A dielectric DBR (7.5 pairs TiO2/SiO2) and an actuation layer (50 nm Ni) are deposited onto the half-VCSEL, and then the MEMS structure is etched. Finally, the mirror membrane is released by dissolving the sacrificial layer in acetone and removing the liquid in a critical point dryer. The VCSEL is tuned by injecting a heating current into the actuation layer on the flexible MEMS, which expands and shifts the cavity resonance towards longer wavelengths. In the followingwe present an optimized half-symmetric cavity design for singlemode emission. Compared to [1] the mesa diameter is enlarged (from 120µm to 200µm) to increase (i. e. flatten) the radius of curvature (RoC) from 420µm to 1.2mm, while keeping the air-gap at around 3.7µm. The threshold gain of fundamental mode and higher order mode during tuning are simulated (Fig. 1 c)) using a 3D model based on coupled mode theory [2]. The resulting gain difference for different oxide aperture diameters Dox is plotted in Fig. 1 d). The cavity supports the single fundamental mode for Dox ≤10µm, while themore expanded higher order transverse modes suffer from clipping at the oxide aperture (for Dox ≤5µm the fundamental mode is affected, too). A microscope image of a fully processed tunable VCSEL is shown in Fig. 1 e). Each chip contains an array of 8×8 tunable VCSELs with a small footprint of 290µm×400µm. The spectrum of a tunable VCSEL with 10µm oxide aperture is shown in Fig. 1 f). The VCSEL emits in fundamental mode with a sidemode suppression ratio SMSR≥25 dB over the tuning range of 12 nm. In comparison, conventional non-tunable 850-nm VCSELs with flat top DBR are singlemode only for Dox ≤3 µm and usually operated at higher current densities.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":"117 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77878781","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":"Numerical simulation of thermal effects in composite Nd:YAG slab laser active medium with collinear zig-zag pumping","authors":"M. Gabalis, V. Girdauskas, A. Aleknavičius, A. Michailovas","doi":"10.1109/CLEOE.2011.5942478","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942478","url":null,"abstract":"Main limiting factor for solid state laser average output power is related to thermal effects in active medium. Optimizing heat removal should be a way to avoid this problem. One of the options is to use cryogenical cooling which is quite complicated for most applications. Other solutions for room temperature are mainly based on relatively large area for heat removal and geometries which allow compensating thermally induced distortions [1,2].","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":"55 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80021159","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":"Second-harmonic nanoparticles for deep tissue in vivo imaging","authors":"R. Grange, Thomas Lanvin, C. Hsieh, Y. Pu, D. Psaltis","doi":"10.1109/CLEOE.2011.5943288","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943288","url":null,"abstract":"Deep tissue in vivo imaging remains a great challenge and we propose to use second-harmonic radiation imaging probes (SHRIMPs) as long-term non bleaching biomarkers. We show that the contrast of SHRIMPs with autofluorescence and endogenous second-harmonic generation (SHG) signal is strong enough for imaging as deep as 100 um in the tail of a living rodent. Currently, optical microscopy often uses fluorescent markers such as green fluorescent proteins (GFPs) and quantum dots to specifically enhance the contrast of selected targets [1]. Such fluorescent agents, however, are limited by photobleaching, blinking, and phototoxicity.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":"27 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80123861","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":"Beat note stabilization of a 10–60 GHz dual polarization Nd:YAG microchip laser through optical down conversion","authors":"Antoine Rolland, M. Brunel, G. Loas, L. Frein, M. Vallet, M. Alouini","doi":"10.1109/CLEOE.2011.5942438","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942438","url":null,"abstract":"In the context of radio-over-fiber and microwave photonic technologies [1], we show an optically carried frequency synthesis working in the range of 10–60 GHz using a dual-polarization microchip laser. An intracavity electro-optical crystal in the cavity turns the laser into a voltage controlled oscillator (VCO) and enables to implement an optical phase-locked loop (PLL). By taking advantage of the short cavity length of the microchip laser, a stabilization scheme at 40 GHz was demonstrated by mixing electrically the beat note to a phase locked dielectric resonator oscillator at 39.5 GHz [2]. Nevertheless, this electrical mixing approach has some limitations in terms of reachable frequencies and tunability, especially when one wants to reach the millimeter-wave range. To overcome theses difficulties, we propose here to operate a novel optoelectronic down-conversion principle before locking.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":"39 1","pages":"1-1"},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80524344","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}