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混沌外腔半导体激光器输出明显存在弛豫振荡特征,弛豫振荡频率小于外腔振荡频率时,外腔半导体激光器输出态是短腔机制;反之,外腔半导体激光器输出态是长腔机制.首先对比分析了弛豫振荡频率为5.6 GHz,腔长对频谱有效带宽的影响.然后同时调节注入电流和载流子寿命来大幅度地增加弛豫振荡频率.最后在弛豫振荡频率为40 GHz、腔长为毫米级(4—20 mm)时,实现由短腔机制到长腔机制的转换,进而分析了外腔反馈率和外腔长对外腔半导体激光器频谱带宽的影响.分析结果表明:短腔机制下,输出混沌态不稳定,0.1 mm的偏差就会导致混沌态与非混沌态之间的转化;长腔机制下,输出混沌态稳定,输出混沌区域较大,证明长腔机制下更有益于获得宽带连续的混沌区域.在弛豫振荡频率为40 GHz、外腔长度为毫米级时,实现了外腔半导体激光器的长腔机制,从而增大了高带宽混沌的参数空间. 相似文献
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粮食贮存过程中由于微生物所引起的变质现象,早在50年前就已经引起人们的注意了。可以总结成六个主要方面:(1)减低出芽率,不利于种用;(2)减低质量,如大豆棉子之榨油,包米之制作淀粉,小麦作面粉等;(3)产生各种不同的颜色;(4)引起不同温度的发热足以升温至60—70℃,甚至80℃;(5)发生酸败。更严重的是 相似文献
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采用Fabry-Perot半导体激光器作为波长转换器件,利用半导体激光器内部的交叉增益调制效应,通过同时将脉冲信号光与连续探测光耦合到半导体激光器,实现了对波长为1552.62nm、重复速率为2.7GHz的光脉冲信号转换到波长为1548.23nm的连续激光,同时实现了脉冲时间抖动的抑制.实验发现,对于确定的半导体激光器及其工作参数,总存在一个固定的纵模,当探测光的波长与该纵模波长一致时可获得最高的波长转换效率和最大的消光比.理论分析了探测光与Fabry-Perot半导体激光器多纵模间的模式选择对波长转换效
关键词:
纵模选择
波长转换
注入锁定
交叉增益调制 相似文献
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We design a hybrid integrated chaotic semiconductor laser with short-cavity optical feedback. It can be assembled in a commercial butterfly shell with just three micro-lenses. One of them is coated by a transflective film to provide the optical feedback for chaos generation while insuring regular laser transmission. We prove the feasibility of the chaos generation in this compact structure and provide critical external parameters for the fabrication by theoretical simulations. Rather than the usual changeless internal parameters used in previous simulation research, we extract the real parameters of the chip by experiment. Moreover, the maps of the largest Lyapunov exponent with varying bias current and feedback intensity K_(ap) demonstrate the dynamic characteristics under different external-cavity conditions. Each laser chip has its own optimal external cavity length(L) and feedback intensity(K_(ap)) to generate chaos because of the different internal parameters. We have acquired two ranges of optimal parameters(L = 4 mm, 0.12 K_(ap) 0.2 and L = 5 mm, 0.07 K_(ap) 0.12) for two different chips. 相似文献
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We experimentally demonstrate a fast random bit generator (RBG) based on bandwidth-enhanced chaotic laser from an optical feedback laser diode with optical injection.The bandwidth-enhanced chaotic signal is sampled and converted to a binary sequence in real time without the need of programming for off-line processing.Multi-rate bit sequences,with the fastest rate of up to 2.87 Gb/s,are obtained with verified randomness. 相似文献
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Perturbation to Mei Symmetry and Generalized Mei Adiabatic Invariants for Nonholonomic Systems in Terms of Quasi-Coordinates
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By introducing the coordination function f, the generalized Mei conserved quantities for the nonholonomic systems in terms of quasi-coordinates are given. Then based on the concept of adiabatic invariant, the perturbation to Mei symmetry and the generalized Mei adiabatic invariants for nonholonomic systems in terms of quasi-coordinates are studied. 相似文献
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近年来,随着分布式光纤传感技术在各大基础设施健康监测领域的广泛应用,人们对能够实现毫米量级精准定位和监测技术的需求日益增长.本文提出了一种基于宽线宽混沌激光的高分辨率分布式光纤测温技术.实验通过改变光反馈混沌源的偏振匹配态和反馈强度等外部参数,产生了–3 dB线宽约为7.5 GHz的宽线宽混沌激光,并在300 m传感光纤实现了空间分辨率为7.05 mm的分布式温度测量.同时,为了抑制光源线宽增加造成的布里渊增益谱恶化,在泵浦路中引入了时间门控技术,其中经脉冲调制后的泵浦光峰值功率提高了约9.5 dB,同时脉冲调制使混沌互相关锁定于脉冲持续时间内,从而布里渊增益谱的信号背景噪声比由约2.28 dB提升为4.55 dB,最终实现了空间分辨率为3.12 mm的分布式温度测量. 相似文献