光电反馈下1550nm VCSELs的非线性动力学特性研究

发布时间：2018-09-02 08:36

【摘要】：半导体激光器在光反馈、光注入、光电反馈等外部扰动下可产生单周期、注入锁定、准周期、混沌等一系列丰富的非线性动力学行为,这些非线性动力学行为在光生微波、混沌保密通信、神经光子学、真随机数获取等领域有着巨大的潜在应用价值。与常规边发射半导体激光器(EELs)相比,垂直腔表面发射激光器(VCSELs)因具有更低的阈值电流、体积小、远场发散角较小、对光纤耦合损耗低、易实现动态单纵模输出和易于大规模集成等优点而备受关注。特别地,位于光纤通信窗口的长波长(1310 nm-1550 nm)VCSELs因易于与现有光纤系统兼容而成为了近年来的研究热点。目前基于VCSELs非线性动力学特性的研究主要集中在光反馈和光注入两种方式,对光电反馈下VCSELs非线性动力学特性的研究大多基于理论分析,而相关的实验报道还较少。因此,实验研究光电反馈下1550 nm VCSELs的非线性动力学特性具有一定的应用价值。本文实验研究了光电正反馈和光电负反馈两种扰动下1550 nm VCSELs的动力学特性,并分析了这些动力学态的演化路径。研究结果表明:当光电正反馈和光电负反馈强度固定不变时,在不同的偏置电流下1550 nm VCSEL可表现出规则脉冲态、准周期态、混沌脉冲态等非线性动力学态。固定偏置电流,调节光电正反馈或光电负反馈强度,1550 nm VCSEL也可呈现规则脉冲态、准周期态、混沌脉冲态等丰富的非线性动力学状态。在光电正反馈下,对于较小偏置电流和弱反馈强度,激光器主要工作在稳态;随着偏置电流的增加,1550 nm VCSEL输出的动力学态在较大的一个偏置电流范围内随光电正反馈强度的增加以规则脉冲态-准周期态-规则脉冲态的方式循环演化;在光电负反馈下,对于较小偏置电流和弱光电负反馈,激光器仍工作在稳态,随着偏置电流增加,VCSEL输出的动力学态通常随负反馈强度的增加以规则脉冲态-准周期态-规则脉冲态的方式循环演化到混沌脉冲态,但当偏置电流增加到一定值后,1550 nm VCSEL输出的动力学态随负反馈强度的增加主要以规则脉冲态-准周期态-混沌脉冲态的方式循环演化。此外,我们给出了激光器在这两种光电反馈下的非线性动力学状态在偏置电流和反馈强度构成的参数空间的分布。
[Abstract]:Semiconductor lasers can produce a series of nonlinear dynamic behaviors such as single period, injection locking, quasi-period, chaos and so on under external disturbances such as optical feedback, optical injection, optoelectronic feedback and so on. Chaotic secure communication, neurophotonics, true random number acquisition and other fields have great potential applications. Compared with conventional side emitting semiconductor laser (EELs), the vertical cavity surface emitting laser (VCSELs) has lower threshold current, smaller volume, smaller far-field divergence angle and lower coupling loss to fiber. The advantages of easy to realize dynamic single longitudinal mode output and easy to integrate in large scale have attracted much attention. In particular, the long wavelength (1310 nm-1550 nm) VCSELs) located in the optical fiber communication window has become a hot topic in recent years because of its compatibility with existing optical fiber systems. At present, the research based on the nonlinear dynamic characteristics of VCSELs is mainly focused on optical feedback and optical injection. The research on nonlinear dynamic characteristics of VCSELs based on optoelectronic feedback is mostly based on theoretical analysis, but there are few related experimental reports. Therefore, the experimental study of the nonlinear dynamic characteristics of 1550 nm VCSELs with optoelectronic feedback has certain application value. In this paper, the dynamic characteristics of 1550 nm VCSELs under both optoelectronic positive feedback and optoelectronic negative feedback are studied experimentally, and the evolution paths of these dynamic states are analyzed. The results show that when the intensity of the positive feedback and the negative feedback is fixed, the nonlinear dynamic states such as regular pulse state, quasi-periodic state and chaotic pulse state can be observed at different bias currents for 1550 nm VCSEL. Fixed bias current, adjusting the intensity of optoelectronic positive feedback or optoelectronic negative feedback can also present regular pulse state, quasi periodic state, chaotic pulse state and other rich nonlinear dynamic states. For the smaller bias current and the weak feedback intensity, the laser mainly works in the steady state under the optoelectronic positive feedback. With the increase of bias current, the dynamic state of 1550 nm VCSEL output evolves in a larger range of bias current with the increase of positive photoelectric feedback intensity in a regular pulse state, quasi periodic state and regular pulse state, and under the negative optoelectronic feedback, the dynamic state evolves in a regular pulse state, a quasi periodic state and a regular pulse state in a large range of bias current. For small bias current and weak optoelectronic negative feedback, the laser still works in steady state. With the increase of bias current, the dynamic state of VCSEL output usually evolves from regular pulse state, quasi periodic state to regular pulse state to chaotic pulse state with the increase of negative feedback intensity. However, when the bias current increases to a certain value, the dynamic state of 1550 nm VCSEL output evolves with the increase of negative feedback intensity, mainly in the form of regular pulse state, quasi-periodic state and chaotic pulse state. In addition, we give the distribution of the nonlinear dynamic state of the laser in the parameter space of the bias current and the feedback intensity under these two kinds of optoelectronic feedback.
【学位授予单位】：西南大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN248;O322

【参考文献】