摘要
通过构建外腔半导体激光器的等效腔模型,并在修正的肖洛-汤斯线宽公式中引入外腔压窄因子,系统模拟了光纤光栅外腔半导体激光器的电流阈值特性和线宽特性。以等效腔模型为基础,综合考虑外腔压窄因子,利用修正后的肖恩-汤斯公式,使用Matlab对外腔激光器的阈值和线宽特性进行了系统的模拟。模拟结果表明:通过增加外腔反射率,可有效增加光子寿命并降低阈值载流子浓度,进而获得较低的阈值电流,对于0.81的外腔等效反射率,阈值电流低至3.83mA;通过增加外腔反射率、耦合效率和外腔长度,可显著压窄线宽至千赫兹量级;此外,合理限制增益芯片尺寸也会压窄线宽。激光器工作电流为60mA时,当外腔光栅反射率由0.1提高至0.9可使阈值电流由9.04mA降低至4.01mA,线宽由95.27kHz降低至1.34kHz;当外腔长度由2cm增加至6cm时,激光器线宽由3.20kHz降低至0.36kHz。
A brief model was used in this letter to perform the linewidth property by introducing the effective reflection coefficient R_（eff）.And then the external cavity linewidth compression factor was also considered to simulate the linewidth properties of the Fiber-grating external cavity semiconductor laser according to the Schawlow-Townes formula revised by Lax..The simulation results show that the threshold current reduces from 9.04 mA to 4.01 mA with the grating reflection（R_（ext））increasing from 0.1to 1.Besides that,it can be seen that the linewidth reduces from 95.27 kHz to 1.34 kHz while the Rextincreasing from 0.1 to 1 when the laser operates at 60 mA.What＇s more,the linewidth can be reduced from 3.20 kHz to 0.36 kHz by increasing the external cavity from 2 to 4cm at the same current.Furthermore,more discussion about other parameters can be reduced to 3.83 mA with the R_（eff）increasing to 0.81.This is because that the higher the R_（eff）,the longer the photon life,which leads to smaller threshold carrier density.The linewidth can be condensed to kHz magnitude by increasing the R_（eff）,coupling coeffient C_0 and the length of the external cavity.
出处
《半导体光电》
CAS
北大核心
2016年第2期165-169,共5页
Semiconductor Optoelectronics
基金
国家自然科学基金项目(61234004
61434005
11404327
11404326)
吉林省科技计划项目(20150520089JH
201401011172JC)
科技部国际合作专项项目(2015DFR10600)
关键词
半导体激光器
外腔
等效反射率
线宽压窄因子
窄线宽
semiconductor lasers
external cavity
effective reflection coefficient
linewidth compression factor
narrow linewidth
