VCSELs与EELs多模弛豫振荡的研究

Study on multimode relaxation oscillation of VCSELs and EELs

根据多模速率方程 ,利用MATLAB提供的SIMULINK软件包对垂直腔面发射激光器 (VCSELs)和边发射激光器 (EELs)多模弛豫振荡进行了研究。结果表明 ,与单模情况相比 ,多模时EELs弛豫振荡频率增大、弛豫和延迟时间缩短 ,而VCSELs动态特性变化不大。与此同时 ,在得出VCSELs的单模工作、高速调制以及提高偏置电流或自发辐射因子可改善两类器件动态特性等结论外还看到 ,VCSELs边模抑制比 (SMSR)随偏置电流变化率高于EELs;自发辐射因子增大时 ,边模强度同比例增大、主模强度减小 ,利用微腔效应有效控制自发辐射因子可以优化VCSELs的单模特性。

Based on multimode rate equations,the relaxation oscillation of vertical-cavity surface-emitting lasers(VCSELs) and edge-emitting lasers(EELs) has been studied through SIMULINK provided by MATLAB.The results show that EELs with multiple longitudinal modes have higher relaxation oscillation frequency and shorter turn-on delay time,which are relatively unchanged for VCSELs case.The simulation results also verify the following conclusions: firstly,VCSELs has the merits of single-mode working and high-speed modulation; secondly,the devices with higher bias current or larger spontaneous emission factor exhibit better temporary characteristics;thirdly,the variation rate of VCSELs’ side-mode suppression ratio (SMSR) with bias current is higher than that of EELs.Furthermore,the side-mode intensities augment at the same rate with increasing the spontaneous emission factor,and the main-mode intensity decreases accordingly.Controlling this factor effectively can optimize the single-mode characteristic of VCSELs.