自发辐射因子对外光反馈下VCSELs非线性行为的影响

利用构建在SIMULLNK平台下垂直腔面发射激光器(VCSELs)动态仿真模型,研究了自发辐射因子对多次外光反馈下VCSEs非线性行为的影响。结果表明,随外腔长(外腔反射率)增加,VCSELs顺次(逆次)经历混沌、多周期、倍周期和单周期区域：进一步得出,增大自发辐射因子可抑制系统的非线性行为,提高器件稳定性。     

奇偶反馈相位共轭腔垂直腔面发射激光器非线性系统的理论研究

针对垂直腔面发射激光器(VCSEL)与相位共轭镜(PCM)这一弱耦合系统,同时考虑到相位共轭镜奇次反馈产生共轭光,偶次反馈产生常规光这一不同于普通平面镜的奇偶效应,构建非即变相位共轭镜奇偶分开的多次反馈理论模型,对多次相位共轭反馈(PCF)下垂直腔面发射激光器非线性动力学行为进行了数值模拟。结果表明,由于引入了奇偶两种不同反馈类型,高次相位共轭镜反馈可明显改变垂直腔面发射激光器的输出动态,即使在弱反馈条件下也如此,而其对稳态特性的影响却恰恰相反。与只考虑一次反馈相比,考虑多次反馈后,弱反馈引起的系统不稳定明显被抑制,混沌区域变小并代之以稳定的倍周期态;而强反馈时,一次反馈对应的从混沌到三分岔的非线性演变方式,在二、三次反馈时分别变成了从倍周期到混沌和从准周期到混沌的演变过程。     

光注入光反馈下VCSEL非线性输出特性分析

为了研究光注入和光反馈对垂直腔面发射激光器(VCSEL)非线性输出特性的影响,基于自旋反转模型(SFM),利用MATLAB数值仿真二者共同作用下VCSEL的非线性输出特性.研究结果表明:在光注入和光反馈同时作用下,VCSEL输出可以实现稳态、单周期、多周期、混沌等非线性行为.通过合理选择注入强度,可实现对VCSEL输出行为的控制.     

相位共轭反馈下垂直腔面发射激光器动态分岔特性的理论研究

在传统半导体激光器动力学方程的基础上，突出了垂直腔面发射激光器(VCSELs)的微腔结构特点以及相位共轭反馈(PCF)的时间反演特性，建立起相位共轭反馈条件下的复合腔仿真模型。仿真结果表明：在外部反射率小于0．05的弱反馈条件下，垂直腔面发射激光器的微腔结构导致了它的动态特性与边发射器件有较大的区别，给出两者在混沌带的出现次数、存在范围以及分岔点的出现条件等方面的比较。相对于常规光反馈(COF)而言，相位共轭反馈的累积相位为零，这使得该机制下垂直腔面发射激光器表现出更为丰富的非线性特性。仿真中观察到常规光反馈经历了三个混沌带，相位共轭反馈经历了两个混沌带且稳定区域较宽；并发现在混沌吸引子产生的过程中常规光反馈光场的实虚部相空间轨迹保持对称，而相位共轭反馈的相空间轨迹则表现为对称的‘建立→破坏→再建立’这样的循环过程。     

外部光反馈对980nm垂直腔面发射激光器振荡特性的影响

研究了外部光反馈对980nm垂直腔面发射激光器(VCSEL)振荡特性的影响.计算了垂直腔面发射激光器及边发射半导体激光器的光反馈灵敏因子.基于复合腔理论,分析了外部光反馈对垂直腔面发射激光器的阈值电流及微分量子效率等振荡特性参数的影响.实验结果表明,当反馈率为10%时,垂直腔面发射激光器的阈值电流由0.63A下降至0.59A,同时斜率效率和输出功率也有所下降.实验结果和理论分析符合得较好.     

相位共轭反馈对外腔VCSEL非线性的控制

提出了相位共轭镜（PCM）与外腔垂直腔面发射激光器（VCSEL）相结合的双耦合腔结构,利用相位共轭反馈（PCF）来控制外腔VCSEL的非线性特性,并与用普通光反馈控制非线性特性的情形进行了比较。结果表明：与普通平面镜相比,PCM对放置位置的变化（波长量级）不敏感且PCM反馈可使外腔VCSEL的稳定范围增大;以外腔反射率在5～7ns^-1间变化的功率分岔图为例发现,PCF可抑制多周期和混沌等不稳定状态,控制VCSEI。输出在单周期或倍周期状态;通过PCF和外腔反馈的共同作用。可得到更高频率的单周期或倍周期输出,实现对VCSEL动态特性控制更加容易。     

DBR微腔激光器典型参数的开关调制响应及控制

以微腔激光器的典型代表垂直腔面发射半导体激光器(VCSEL)为例，选择自发辐射因子为控制参数，数值模拟了大信号深度调制情形下VCSEL的非线性动力学特性，实现了类似于边缘发射激光器的分岔，周期加倍分岔，多稳和混沌状态的稳定控制，得到分岔点位置和周期轨道与控制参数的变化关系，以及相应地调制参量和自发辐射因子的取值范围，计算结果较好地拟合了文献实验结果。     

长波长垂直腔面发射激光器

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。     

新型材料InGaNAs的生长与应用前景

详细介绍了一种新型半导体材料(InGaNAs)的生长特点及其在制作高特征温度的长波长量子阱激光器、长波长垂直腔面发射激光器、长波长光泵垂直外腔面发射激光器、半导体可饱和吸收镜和长波长谐振腔增强探测器方面的优势。     

外部光反馈作用下垂直腔面发射激光器的电光特性

研究了外部光反馈对垂直腔面发射激光器（VCSELs）电光特性的影响。通过计算光反馈参数对比了VCSELs与边发射激光器（EELs）的光反馈灵敏性。基于复合腔理论计算了存在外部光反馈时垂直腔面发射激光器的阈值电流及斜率效率等电光特性参数。实验结果表明,分布布拉格反射镜（DBR）反射率不同的VCSEL,在反馈率为10%的外部光反馈作用下,其阈值电流及斜率效率发生了不同程度的变化。实验结果有效验证了理论计算的结论。     

Theoretical study on controlling nonlinear behaviors of a coupled-cavity VCSEL by external optical injection

A master-slave configuration used to control the nonlinear behaviors arising in a vertical cavity surface emitting laser (VCSEL) with strong external optical feedback is established. In terms of bifurcation diagram, time and frequency domain, the influence of the continuous optical injection from the master VCSEL on the nonlinear characteristics of the slave is investigated theoretically. For relatively weak injection, the slave still keeps its intrinsic nonlinear state. With increasing the injection strength, these nonlinear behaviors evolve to periodic fluctuation, and at last are replaced by the steady-state (e.g. the critical injection parameter for steady-state is 1.2 when external cavity's reflectivity and length are 4%and 4 cm, respectively). During this evolution the bifurcation-contraction phenomena are also observed.     

Investigation of polarization properties of VCSELs subject to optical feedback from an extremely short external cavity-part II: experiments

The effect of isotropic optical feedback from an extremely short external cavity on the emission properties of vertical-cavity surface-emitting lasers (VCSELs) is experimentally investigated. When changing the external cavity length a modulation of the total power and the wavelength emitted by the VCSEL is observed with a period of half the wavelength of operation of the device. When biasing the VCSEL around its solitary (without optical feedback) polarization switching (PS) current, PS between the two linearly polarized modes is observed by changing the external cavity length. This PS is found to occur through a hysteresis region. Our experimental results show a modulation of the PS currents and the hysteresis width when changing the external cavity length with a period of half the wavelength of operation. The experimental results are well explained by a two mode rate equation model.     

自发辐射因子对VCSEL在大信号调制下的分岔及混沌行为的影响

在SIMULINK平台下开发了垂直腔面发射激光器 (VCSEL)的动态仿真模型 ,实施高频大信号调制情形下的动态仿真 ,避免了大信号近似处理 ,提高了计算精度。选择自发辐射因子为控制参量 ,定量分析它对VCSEL稳定性和分岔点的影响。结果表明 ,在所选参量条件下 ,自发辐射因子数值在 5× 10 -3 ～ 5× 10 -5之间时 ,随着调制深度的加深 ,VCSEL峰值光子密度产生分岔 ,呈现双稳、多周期 ,最后回到单周期 ;当小于 10 -5时 ,进入混沌状态的演变过程。同时分岔点的移动依赖于自发辐射因子的大小 ,调控自发辐射因子可以抑制系统的非线性行为。仿真结果与文献实验结果吻合     

Influence of optical feedback time-delay on power-drops in vertical-cavity surface-emitting lasers

The influence of optical feedback time delay on the average period of low-frequency fluctuations (LFF) in external cavity vertical-cavity surface-emitting lasers (VCSELs) is studied experimentally. The regularity of power dropouts is shown to increase with increased external cavity length. Coexistence of LFF and stable operation is observed when the external cavity length is close to the VCSEL coherence length.     

光栅外腔提高VCSEL微波调制效率实验研究

实验研究了垂直腔面发射激光器(vertical cavity surface emitting laser,VCSEL)在闪耀光栅作为外腔反馈时的直流和微波调制特性.VCSEL底部端面和外部闪耀光栅组成法布里-珀罗(Fab-ry-Perot,FP)腔,由于闪耀光栅的反馈作用,可以提高VCSEL微波调制效率.在VCSEL...     

Dynamics and chaos stabilization of semiconductor lasers withoptical feedback from an interferometer

This paper studies dynamical behaviors and noise properties of semiconductor lasers with optical feedback from an interferometer, i.e., two external cavities. Bifurcation diagrams versus external-cavity length and reflectivity reveal the existence of stable regions for fixed states and limit cycles. The steady-state analysis for a laser diode with two external feedbacks is performed, which shows that oscillation modes are locked at minimum excess gain modes. Oscillation frequencies of limit cycles show discrete transitions with the variation of ratios between two external-cavity lengths and reflectivities. It is proposed that such a model might be applied to stabilization of the feedback-induced chaos in external-cavity semiconductor lasers since the stable region is quite robust for wide parameter ranges. Intensity and phase noises are examined and the results indicate that the low-frequency relative intensity noise level and the linewidth can be greatly improved when the laser output is a fixed state or a limit cycle     

Threshold and modal characteristics of composite-resonator vertical-cavity lasers

We report the operation of a vertical-cavity surface-emitting laser (VCSEL) with two active, coupled optical cavities. In contrast to a conventional single-cavity VCSEL, the coupling between the two electrically independent active regions produces emission into two longitudinal modes. The light output versus current characteristics are presented under various biasing conditions in each cavity. Laser operation is achieved with current injection into only one cavity, and additional current injected into the other cavity changes the effective threshold current measured. The longitudinal and transverse modes are characterized, and it is found that the modal evolution of the laser can be modified by current injection into each cavity.     

A New Transmission Line Microcavity Model for Vertical Cavity Surface Emitting Lasers

In this paper we present a new transmission line microcavity model for vertical cavity surface emitting lasers (VCSEL). The model is based on optical wave equations and implemented with state-space techniques to predict the lasing modes and analyze the decay properties of the Fabry-Perot (FP) cavities. The model is used to analyze microcavities in both time and frequency domains in terms of material and physical parameters of the lasers, and provide a simple and fast way to optimize the cavity length, reflective mirror and active region of the lasers.