共查询到20条相似文献,搜索用时 125 毫秒
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理论分析了内部损耗、内量子效率对激光器输出功率的影响,并采用PICS3D软件对852 nm法布里-珀罗(FP)激光器进行综合优化设计.设计的器件具有小远场发散角、低内部损耗和高内量子效率等特点,并在大电流下能够实现稳定的高功率输出.实验制备了基横模852 nm FP激光器,内部损耗小于1cm-1,快轴发散角为42.3°... 相似文献
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在量子阱半导体激光器中,量子尺寸引起的衍射效应使半导体激光器的光束质量很差。分别限制结构的垂直结平面发散角在40°左右,使得光束整形系统比较复杂,限制了半导体激光器的直接应用。为解决这一问题,提出了降低垂直结平面发散角的要求。回顾了小发散角半导体激光器的技术发展及应用,对具有小发散角的模式扩展波导结构进行了理论模拟和实验验证,获得了优化的结构。采用MOCVD外延技术生长了外延片,制作了高峰值功率脉冲激光器,获得了快轴发散角小于25,°峰值功率大于80W的半导体激光器,在激光引信应用中获得良好效果。 相似文献
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半导体激光器远场发散角的近似计算 总被引:3,自引:3,他引:0
从半导体激光器的单模工作条件出发,提出一个远场发散角的近似公式。比较用此近似公式计算结果与数值计算、二阶矩近似计算的结果发现,在半导体实际应用中的波导层范围,该公式能减少计算难度,同时能够满足精度要求。 相似文献
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大功率半导体激光束非球面准直系统的优化设计 总被引:2,自引:1,他引:2
为实现空间激光束的远距离传输,利用矢量折射定理研究了大功率半导体激光器发散光束经非球面、非轴对称准直系统的光传输特性。对空间光线传输得出了矩阵传递公式,并针对大功率线源半导体激光器的发散光束进行了高精度的准直优化设计。为实现对激光束的进一步准直,利用光学设计软件CODE-V设计了卡塞格伦光学天线。利用两点法对发散角进行了实验测试,结果表明优化设计的准直系统发散角为1.924 mrad,经光学天线进一步准直后的发散角为96.2μrad。本空间光线追迹方法对复杂光学系统的精确计算具有一定参考意义,所设计的大功率线源激光束准直系统能广泛应用于远距离激光通信系统中。 相似文献
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理论仿真和实验制备了AlGaInAs/InP材料1.55 μm小发散角量子阱激光器。为了扩展近场光场并减小内损耗,将一个非对称模式扩展层插入到外延结构的下盖层当中。仿真结果表明,该模式扩展层除了少量增加激光器阈值电流以外,在不影响激光器其它性能的情况下能显著减小激光器的垂直远场发散角。实验结果与理论仿真高度吻合。成功制备出脊宽4 μm,腔长1000 μm的脊波导小发散角激光器。在端面未镀膜的情况下,该激光器阈值电流为56 mA,输出功率为17.38 mw@120 mA,斜率效率可以达到0.272 W/A。实验测得垂直远场发散角为29.6°,相比较传统激光器减小了约35.3%。 相似文献
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An asymptotic theory is presented with which the reduction in aperture efficiency caused by diffraction from a subreflector edge can be calculated for any dual-reflector system. The theory is applied to conventional Cassegrain antennas, for which approximate analytical effieiency formulas are derived. These formulas show that subreflector diffraction may represent a significant efficiency loss even for subreflector diameters as large as 20 wavelengths. The formulas are used to obtain an optimum subreflector size which represents the best trade-off between losses due to subreflector diffraction and geometrical shadowing. 相似文献
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For pt.I see ibid., vol.38, no.9, p.1350-8 (1990). Asymptotic formulas that can be used to calculate diffraction losses in a multireflector antenna without having to integrate rapidly varying fields over the reflector surfaces and the aperture are presented. Two kinds of losses caused by edge diffraction are considered: the reduction in antenna efficiency and the increase in spillover. The asymptotic formulas are obtained from the standard transition region field introduced in part I and are expressed in terms at the Δρ defined there 相似文献
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V. I. Belousov G. G. Denisov N. Yu. Peskov 《Journal of Infrared, Millimeter and Terahertz Waves》1991,12(9):1035-1043
The article presents results of theoretical and experimental investigation of quasioptical multiplexer based on reflecting diffraction grating. Diffraction losses caused by reflection into mirror harmonic, and by angle divergence of wave beams are calculated. In an experimental multiplexer, wave beams with the frequencies 70 GHz and 79 GHz were mixed with power losses less than 1%. 相似文献
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We report results of studies of laser beam divergence, laser beam intensity profiles and spatial and temporal laser pulse characteristics for a rectangular bore strontium recombination laser operating on the 430.5 nm Sr transition at high pulse rates (3-10 kHz). Beam divergence is found to be very nearly diffraction limited for a flat-flat optical cavity, with a very uniform spatial distribution of laser intensity under optimum operating conditions. Laser pulse characteristics provide an indication of plasma conditions across the laser tube 相似文献
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Experimental observations on a double-pass methane Raman amplifier pumped by a KrF laser demonstrate efficient photon extraction (75-85 percent) of multiple pump pulses and high stage gain (10-20) with simultaneous intensity gain or "pulse compression" of about 2. The Stokes beam divergence is about 2.5 times the diffraction limit and is unchanged in the amplifier to within the precision of the experiment. The pump pulses are of poor spatial quality and propagate through the amplifier in a light guide. A simple one-dimensional theoretical model fits the results of the experiment. Analysis using the model permits a projection of the performance of very large final Raman amplifier-compressor stages for fusion laser systems. These systems, with somewhat better controlled pulse shapes than those used in the experiment, can deliver average intensity gains of 2-3 at a net energy conversion efficiency (all losses included) of about two thirds and a stage gain of 30. 相似文献
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The single-mode laser diode to single-mode fiber coupling efficiency is analyzed for couplers with glass ball lenses and silicon plano-convex lenses, respectively. The contributions of the different origins of loss are given. It is found that in nearly all cases, most of the total loss is determined by the spherical aberration of the lends that collects the divergent laser diode (lens 1). This loss is calculated for a variety of glass ball lenses and silicon plano-convex lenses are shown to be dependent on the laser diode spot size (or divergence angle). The minimum loss of a coupling configuration is determined with good accuracy by the parameters of lens 1; a single additional parameter, the effective laser diode spot size (or effective divergence angle) for the laser diode; and the coupling arrangement. The calculated losses are compared with experimental values. In most cases, theory and measurement agree very well; differences are discussed 相似文献
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Suning Tang Chen R.T. Garrett L. Gerold D. Li M.M. 《Lightwave Technology, Journal of》1994,12(11):1971-1975
We utilize a novel diffraction formalism to study the crosstalk effect in a highly parallel free-space optical interconnect based on two-dimensional arrays of surface-emitting laser diodes, microlenses, and photodetectors. The diffraction induced crosstalk between adjacent laser diodes in each detector to the system limitations is investigated. Optimum design rules and formulas are given for the first time, to include the relation of channel packaging density and interconnect length to the design parameters of the optical interconnect components. The design formulas developed here yield an optimum detector size and indicate a tradeoff between channel packaging density and interconnect length. The feasibility of such a free-space interconnect with a channel packaging density of 3460 channels/cm2 and 2.0 cm interconnection length is determined using typical parameters of detector radius from ~5 to ~45 μm, lens radius of 85 μm, and laser diode radius of ~5 pm operating at wavelength 0.67 pm for signal-to-noise ratio above 17 dB. Some experiments were conducted to measure the diffraction induced crosstalk and optical link efficiency 相似文献