1550 nm垂直腔面发射激光器自旋反转模型中关键参量数值的实验测定和理论研究

发布时间：2018-01-07 08:42

本文关键词：1550 nm垂直腔面发射激光器自旋反转模型中关键参量数值的实验测定和理论研究　出处：《西南大学》2017年硕士论文　论文类型：学位论文

【摘要】：半导体激光器(Semiconductor Lasers,SLs)作为光通信领域最重要的光源,凭借其独特的优点而得到飞速的发展。垂直腔面发射半导体激光器(Vertical-Cavity Surface-Emitting Lasers,VCSELs)具有体积小、阈值低、高调制效率、单纵模输出等诸多优势,而受到广泛的关注。近年来,短波长VCSELs的制作工艺较为成熟,工作性能较为稳定,在近距离和中程距离光通信领域中被广泛使用;长波长VCSELs的制作工艺也日臻完善,尤其是1550 nm VCSELs处在零色散、低损耗窗口位置,在长距离、大容量干线光纤通信领域具有较大潜能和应用价值。故此,针对1550 nm VCSELs进行系统性理论和实验研究就具有非常重要的意义。在1550nm VCSELs的理论分析工作中,自旋反转模型(Spin-Flip Mode,SFM)是目前用于分析1550 nm VCSELs非线性动力学特性最常用的模型。在给定偏置电流的条件下,需提前给出模型中关键参量的数值,才能通过数值求解得到两个偏振分量随时间变化的序列,从而对其输出的动力学特征进行分析。故而这些参数的取值对1550nm VCSELs输出的动力学特性具有较大的影响。因此,如何准确测定这些参数是能否正确预测1550 nm VCSELs动力学特性的关键。本文基于自由运行和平行光注入1550 nm VCSEL的输出测量结果,对描述1550 nm VCSEL特性的SFM中关键参量(光场衰减速率k、总载流子衰减速率γN、线宽增强因子α、有源介质双折射速率γp、自旋反转速率γs、有源介质线性色散速率γa)的数值进行了估计。通过实验测定1550 nm VCSEL的噪声谱估计出光子寿命(τp)的值,考虑到弛豫振荡衰减速率的增益饱和效应,对τp做出了修正,进而根据k=1/(2τp)的关系求得k的值;根据1550 nm VCSEL的弛豫振荡频率与电泵浦参量二者间的关系,求得γN的值;利用平行光注入1550 nm VCSEL确定稳定注入锁定区霍普夫分岔所需的最小失谐频率,粗略估计出α的值;根据实验测得的自由运行的1550 nm VCSEL光谱中两个偏振分量的频率差值求得γp的值;利用γs和γp的关系,求得γs的值;通过分析求得γa的值;利用上述所得关键参量的数值进行仿真,得到的动力学谱图与实验测得的平行光注入1550 nm VCSEL的动力学图谱进行对比,对α值进行了微调。为了进一步证明得到的关键参量的数值的正确性,最后利用测定的关键参量仿真偏振光注入提高1550 nm VCSEL的混沌信号带宽,仿真的结果与文献实验结果进行了对比,且二者能够很好地吻合,最终说明测定得到的六个关键参量的数值是正确的,所用的测定方法是合理的。
[Abstract]:Semiconductor LasersSys (SLS) is the most important light source in the field of optical communication. Vertical-Cavity Surface-Emitting Lasers has been developed rapidly because of its unique advantages. VCSELs have many advantages, such as small volume, low threshold, high modulation efficiency, single longitudinal mode output and so on. In recent years, the fabrication technology of short wavelength VCSELs is more mature. The work performance is relatively stable and is widely used in the field of short and medium range optical communication. The fabrication technology of long wavelength VCSELs is also improving, especially 1550nm VCSELs is in the position of zero dispersion, low loss window and long distance. Large capacity trunk fiber communication field has great potential and application value. Systematic theoretical and experimental studies on 1550nm VCSELs are of great significance. In the theoretical analysis of 1550nm VCSELs. Spin-Flip Mode. SFM) is the most commonly used model to analyze the nonlinear dynamic characteristics of 1550nm VCSELs. Under the condition of given bias current, the numerical value of key parameters in the model should be given in advance. Only by numerical solution can we obtain two series of polarization components changing with time. Therefore, the value of these parameters has a great influence on the dynamic characteristics of 1550nm VCSELs output. How to accurately determine these parameters is the key to correctly predict the kinetic characteristics of 1550nm VCSELs. The output of VCSEL is measured. The key parameters (optical field attenuation rate k, total carrier attenuation rate 纬 N, linewidth enhancement factor 伪, birefringence rate 纬 p of active medium) in SFM describing 1550nm VCSEL characteristics are investigated. The spin inversion rate 纬 s and the linear dispersion rate 纬 a of the active medium are estimated. The photon lifetime (蟿 p) is estimated by measuring the noise spectrum of 1 550 nm VCSEL. Considering the gain saturation effect of relaxation oscillation attenuation rate, 蟿 p is modified and the value of k is obtained according to the relation of 1 / 2 蟿 p. According to the relationship between the relaxation oscillation frequency of 1550nm VCSEL and the pump parameter, the value of 纬 N is obtained. The minimum detuning frequency required for the Hopf bifurcation in the stable injection locking region is determined by using the parallel optical injection of 1550nm VCSEL, and the value of 伪 is roughly estimated. The value of 纬 p is obtained from the frequency difference of the two polarization components in the free-running 1550nm VCSEL spectrum measured experimentally. Using the relation between 纬 s and 纬 p, the value of 纬 s is obtained. The value of 纬 a is obtained by analysis. By using the numerical simulation of the above key parameters, the kinetic spectra obtained are compared with the kinetic spectra obtained by parallel light injection of 1550nm VCSEL. In order to further prove the correctness of the obtained key parameters, the 伪 value is fine-tuned. Finally, the chaotic signal bandwidth of 1550nm VCSEL is improved by using the measured key parameters, and the simulation results are compared with the experimental results, and the two results are in good agreement with each other. The results show that the values of the six key parameters are correct and the method is reasonable.
【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

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