共查询到20条相似文献,搜索用时 156 毫秒
1.
GAO Chunqing RENG Norbert 《Chinese Journal of Lasers》2000,9(4):303-307
1 Introduction Inmanyapplicationsthenearfieldemissionandthebeamparametersofasemiconductorlaserarerequired .Comparedtothemeasurementofthenearfieldsofsolidstatelaserandgaslaser,themeasurementofthenearfieldofasemiconductorlaserismoredifficult.Thereasonis… 相似文献
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Hiroshi Murata Katsuya Shibasaki Kazuhisa Yamamoto Yasuyuki Okamura 《Optical Review》2014,21(1):79-82
Speckle contrast of images generated by a red semiconductor laser was measured precisely utilizing a state-of-the-art speckle measurement system with a cooled CCD camera with auto-light-power-level adjustments. By using high-frequency signal (~500 MHz) superposition to the single-mode semiconductor laser, the 3 dB spectrum of the laser beam was broadened from 0.1 to 2.3 nm. As a result, the speckle contrast value was drastically reduced from 0.9 to 0.2. 相似文献
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High-contrast microscopy of semiconductor and metal sites in integrated circuits is demonstrated with laser-scanning confocal reflectance microscopy, one-photon (1P) optical-beam-induced current (OBIC) imaging, and detection of optical feedback by means of a commercially available semiconductor laser that also acts as an excitation source. The confocal microscope has a compact in-line arrangement with no external photodetector. Confocal and 1P OBIC images are obtained simultaneously from the same focused beam scanned across the sample plane. Image pairs are processed to generate exclusive high-contrast distributions of semiconductor, metal, and dielectric sites in a GaAs photodiode array sample. 相似文献
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StudyingtheMode-SpectraCharacteristicsofAnAbove-ThresholdBiasedSemiconductorLaser¥XIAGuangqiong;WUZhengmao;CHENJianguo;LUYucu... 相似文献
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利用直接耦合的激光器放大器对,观察了弱信号机制下Fabry-Perot的半导体激光放大器的光放大.测量了放大器增益随放大器注入电流的变化关系,并将实验结果同理论模型相比较,发现理论和实验是一致的.把F-P放大器看作是一个光电探测器,通过测量放大器的短路光电流,得到了激光器同放大器之间的耦合效率. 相似文献
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本文介绍了半导体激光器的典型特性,探讨了用其相干长度进行干涉计量的新方法,并进行了眼球光学长度的测量的实验。 相似文献
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通信用大功率半导体激光器的温控系统 总被引:5,自引:0,他引:5
主要叙述通信用大功率半导体激光器曙控原理及激光组件的构成。解决了大功率半导体激光器工程应用中输出功率和波长随温度变化较大的问题。 相似文献
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NewApproachtoInvestigationofTunableExternalCavitySemiconductorLasers¥LUHongchang;LUOBin(SouthwestJiaotongUniversity,Chengdu61... 相似文献
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With a proper perturbation, even a single-mode semiconductor laser can exhibit highly complex dynamical characteristics ranging from stable, narrow-linewidth oscillation to broadband chaos. In recent years, three approaches to invoke complex nonlinear dynamical states in a single-mode semiconductor laser have been thoroughly studied: optical injection, optical feedback, and optoelectronic feedback. In each case, the nonlinear dynamics of the semiconductor laser depends on five intrinsic laser parameters and three operational parameters. The dynamical state of a given laser can be precisely controlled by properly adjusting the three operational parameters. This ability to control the dynamical behavior of a laser, combined with the understanding of its characteristics, opens up the opportunity for a wide range of novel applications. This paper illustrates the utilization of the rich nonlinear dynamics of single-mode semiconductor lasers by focusing on the period-one oscillation for its applications in tunable photonic microwave generation, AM-to-FM conversion, and dual-frequency precision Doppler lidar. 相似文献
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本文报导了一种测量光耦合效率η的新实验方法。这个方法是建立于p-n结短路光电流原理上的。本文推导出适合于行波激光放大器的光耦合效率的公式。短路光电流用一检流计测量,利用公式获得光耦合效率的实验值。利用实验所测光耦合效率,测量了行波激光放大器的增益随注入电流变化的规律,其结果和实验符合。另外本文还介绍了在脉冲注入电流条件下测行波半导体激光放大器增益的实验方法。 相似文献
13.
Lou Qihong 《Hyperfine Interactions》1987,37(1-4):275-290
Performance of an X-ray preionised XeCl excimer laser is presented, a maximum output of 30 W (1.2 J/25 Hz) has been obtained.
This laser was applied in laser semiconductor processing, laser deposition and laser photolithography. 相似文献
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P. Malý 《Czechoslovak Journal of Physics》2002,52(5):645-667
A large amount of work has been worldwide directed to understand the properties of semiconductor nanostructures. Ultrafast
lasers with pulsewidths of a few femtoseconds allowed the investigation of the dynamics of elementary excitations in semiconductor
structures on ultrashort time scales. Recent progress in technology made it possible to fabricate semiconductor nanocrystals
(i.e. crystals of nanometer dimensions) of well-defined properties. The purpose of this paper is to review the understanding
of carrier relaxation and recombination processes in semiconductor nanocrystals as studied by ultrafast laser spectroscopy.
The up-to-date techniques of ultrafast laser spectroscopy as well as the fabrication of semiconductor nanocrystals are discussed
in some detail. 相似文献
16.
E. Kasapoglu C. A. Duque H. Sari I. Sökmen 《The European Physical Journal B - Condensed Matter and Complex Systems》2011,82(1):13-17
By using the compact-density matrix approach, the effect of a nonresonant
intense laser field on the linear and nonlinear optical absorptions based on
intersubband transitions and the refractive index changes in an asymmetric
semiconductor quantum well have been presented. Our results show that the
peak position of the absorption coefficient is sensitive to intense laser
field, the absorption maximum shifts towards lower energies for increasing
intense laser field value. Also we observe as the intense laser field
strength increases, the total refractive index change has been increased in
magnitude and also shifted towards lower energies. The results indicate that
linear and nonlinear optical properties of the low dimensional semiconductor
heterostructures can be adjusted in a desired energy range by using intense
laser field. 相似文献
17.
A simple, low-cost spectrometric system for non-destructive quantitative measurement of water vapour density enclosed in halogen
lamp bulbs has been developed using a near-infrared semiconductor laser system. A working curve was successfully obtained
using a temperature stabilized, perturbed-injection-current near-infrared semiconductor laser system. A minimum detectable
water vapour density as low as several tens of ppm with good reliability has been confirmed.
This revised version was published online in November 2006 with corrections to the Cover Date. 相似文献
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Z. Zhang T. Nakagawa K. Torizuka T. Sugaya K. Kobayashi 《Applied physics. B, Lasers and optics》2000,70(7):S59-S62
We developed a gold reflector based semiconductor saturable absorber mirror that has a sufficiently high reflectivity and a broad bandwidth and has been used to initiate the mode locking in a Cr4+:YAG laser. The laser achieved a similar efficiency to the lasers with Bragg-reflector-based semiconductor saturable absorber mirrors, but delivered a much broader spectrum and a shorter pulse. 相似文献
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在长距离无线光通信中,接收点光功率密度与光束发散角平方呈反比关系,为了获得小的发散角和大的功率耦合效率,要求准直系统有较大的数值孔径(NA),但数值孔径过大会增加像差,因此合理设计功率耦合效率与准直系统的数值孔径就非常重要。该文对半导体激光器光束准直系统中功率耦合效率进行了研究,给出了半导体激光器光束功率耦合效率与k(孔径半径与孔径处等效光束半径之比)的关系表达式,并结合激光器光束准直系统,给出了半导体激光器光束功率耦合效率与准直系统数值孔径的关系表达式。该研究结论对于半导体激光器光束准直系统设计具有参考作用。 相似文献
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为了实现高频率的调制激光输出,设计了一种驱动系统由信号放大、电流调制、过流保护和具有慢启动功能的直流偏置电路高度集成的半导体激光高频调制系统。此系统采用了结构简单的直接调制方式,运用线性调频的高频信号去控制半导体激光器发射激光的强度,从而实现高频调制。在运用OrCAD/PSpice对高频调制驱动系统进行模拟仿真的基础上,最终研制出的半导体激光高频调制系统实现了频率为40.02 MHz、直流偏置为493.326 mA、正弦波调制电流峰峰值为850 mA的高频调制输出,调制激光平均功率为300 mW。 相似文献