共查询到20条相似文献,搜索用时 109 毫秒
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Yan Chang-ling Ning Yong-qiang Qin Li Liu Yun Wang Qing Zhao Lu-min Sun Yan-fang Jin Zhen-hua Tao Ge-tao WangChao Liu Jun Wang Lijun Zhong Jingchang 《光机电信息》2004,(4):1-12
给出了长波长垂直腔面发射激光器的器件结构的发展现状,同时对GaInNAs/GaAs垂直腔面发射激光器进行了详细的介绍。最后,给出了所设计的新型1.3μm GaInNAs/GaAs长波长垂直外腔面发射半导体激光器的结构设计,有源区量子阱由980nm半导体激光二极管进行泵浦。这种器件设计实现了激光二极管泵浦与长波长垂直腔面发射激光器的有机结合,同时具有两者的优点。此外,本文还对器件的阈值特性和光输出功率进行了理论计算。 相似文献
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二维光子晶体对面发射激光器横模控制研究 总被引:1,自引:0,他引:1
垂直腔面发射激光器的单模输出特性在光网络数据传输光互连、光存储和激光打印中有重要的应用.传统的氧化限制型垂直腔面发射半导体激光器由于串联电阻大、发热严重而很难工作在单模状态.二维光子晶体结构可以有效地控制垂直腔面发射激光器的横向模式,使器件工作在单模状态下.从理论上系统研究了光子晶体垂直腔面发射半导体激光器的单模条件,成功设计了一组单模光子晶体垂直腔面发射半导体激光器,并通过常规工艺制作出功率0.6 mW、边模抑制比大于30 dB、阈值电流4 mA、远场发散角8.4°、不受电流注入影响的单模光子晶体垂直腔面发射半导体激光器.实验证明:光子晶体可有效地进行横模控制. 相似文献
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In this letter, an accurate nonlinear Volterra series analysis for vertical-cavity surface-emitting lasers (VCSELs) is presented. Closed-form expressions for the modulation response, harmonic distortions, and second- and third-order intermodulation distortions are derived. Moreover, the suggested nonlinear model avoids the numerical solution of laser rate equations and provides in-depth insight of a distortion analysis of VCSEL. 相似文献
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Analytical expressions for the second-order harmonic and the third-order intermodulation distortions of laser diodes with optical feedback are derived. It is shown theoretically and experimentally that optical feedback from the transmission fiber considerably enhances intermodulation and harmonic distortions of laser diodes. Third-order intermodulation distortions up to -15 dBc must be expected for two-tone modulation and low-intensity modulation indexes m ≈7% per carrier, which affects the performance of subcarrier multiplexed (SCM) communication systems. To avoid additional distortions the external feedback level must be two orders of magnitudes lower than the critical external feedback level of the laser diode 相似文献
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A mathematical model for the transfer function of the Michelson interferometer with Gires-Tournois interferometers in its arms is presented. The model, basically a sine-series function, can easily yield closed-form expressions for the amplitudes of the harmonic and intermodulation components of the output when the input is formed of large-amplitude multisinusoidal voltage. The special case of two-tone equal-amplitude input voltage is considered in detail. The results show that the third-order intermodulation component is always higher than the third-harmonic component. The results also show that the linearity of the Michelson interferometer with Gires-Tournois interferometers in its arms improves with the increase of the front mirror reflectivity. Moreover, the results show that the third-order intermodulation exhibits a minimum for relatively large values of the front mirror reflectivity. Furthermore, compared with the traditional Mach-Zehnder interferometer, the results show that a reduction of 15 dB in the third-order intermodulation can be achieved even for relatively small values of the front mirror reflectivity. 相似文献
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Berceli T. Frigyes I. Gottwald P. Herczfeld P.R. Mernyei F. 《Microwave Theory and Techniques》1992,40(5):910-915
When the number of TV channels is high, a significant harmonic and intermodulation distortion arises. These distortions can be reduced by improving the modulation linearity of the laser or by applying a more appropriate modulation method. Both solutions are discussed and evaluated in detail. The linearity has been significantly improved by applying an active matching technique. The improvement achieved by the new driving circuit over the conventional one is 15 dB considering the third harmonic distortion. The sensitivity of QPSK TV transmission to disturbing interferences has been investigated. A so-called group modulation method offers a better approach for optical multicarrier TV transmission 相似文献
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The harmonic and intermodulation distortions induced by fiber dispersions are analyzed. The concept of the common frequency (or common period) is introduced for the analyses of intermodulation. It is shown that both the magnitude and shape of the sum terms of the intermodulation are quite similar to those of the harmonic distortions of the same order. The difference terms of the intermodulation are much smaller if the subcarrier frequencies are not far apart from one another. It is concluded that the influence of dispersion-induced distortions depends on the subcarrier frequency, the dispersion constant, the length of the fiber, and the modulation indexes. Accompanied by the development of high-frequency and large capacity systems and single-mode lasers with extra narrow spectrum, the dispersion-induced distortions may become one of the most important factors in determining information capacity and transmission distance 相似文献
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P.-L. Liu B.J. Li Y.S. Trisno 《Photonics Technology Letters, IEEE》1991,3(2):144-146
An electrooptic modulator which offers high linearity and low intermodulation distortion (IMD) is proposed. The modulation characteristics, harmonic and intermodulation distortions, are calculated. In the two-tone test with an optical modulation depth of 16% for each channel, the third-order IMD is expected to be as low as -95 dB. Such a linearized electrooptic modulator used in conjunction with diode-pumped solid-state lasers can be expected to outperform directly modulated injection lasers for CATV transmission systems.<> 相似文献
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垂直腔面发射激光器DBR结构参数的优化设计 总被引:4,自引:0,他引:4
采用光学传递矩阵法 ,研究了生长偏差对分布布拉格反射 (DBR)结构反射特性的影响 ,并探讨了两种DBR结构改进方案。结果表明 ,周期厚度偏差将使DBR反射谱发生较大偏移 ,在相位匹配条件下减小高折射层厚度可以降低DBR吸收损耗、提高反射率 ,反向改变顶层和底层DBR周期厚度可以提高垂直腔面发射激光器边模抑制比 相似文献
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Knodl T. Straub A. Golling M. Michalzik R. Ebeling K.J. 《Photonics Technology Letters, IEEE》2001,13(9):930-932
We present theoretical and experimental results on the scaling properties of bipolar cascade vertical-cavity surface-emitting lasers with respect to active region stacking and out-coupling mirror reflectivity. The measurement results at around 980-nm wavelength confirm the theoretically expected behavior of an almost linear increase in slope efficiency and a reduction in threshold current density with the number of stages. A three-stage laser shows a differential quantum efficiency of 128% in continuous-wave operation at room temperature. For the threshold current density, we obtain a decrease from 3.75 kA/cm2 for the conventional VCSEL to about 1.2 kA/cm2 for a three-stage device. Such multi-diode cascade VCSELs are highly interesting for optical links, analog systems, and high-power applications 相似文献
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利用介质膜高反镜实现“猫眼”目标有效隐身 总被引:1,自引:0,他引:1
针对激光主动探测系统的主要工作波长为1 064nm,提出了一种利用介质膜高反镜实现"猫眼"目标隐身的方案。利用单波长介质膜高反镜的反射率特性,将介质膜高反镜与"猫眼"目标光轴以一定角度装配,推导了加载介质膜高反镜的理想"猫眼"目标回波功率模型,并给出了典型算例。通过实验方法分析了介质膜高反镜的反射率特性,修正了45°激光入射角的平均反射率值。典型"猫眼"目标的外场实验表明,在有限"牺牲"成像质量的前提下,介质膜高反镜可大大降低"猫眼"目标的"猫眼"效应,实现光电装备的有效隐身。 相似文献