不同的外部光反馈强度下外腔半导体激光器大信号调制特性

Large signal modulation characteristics of the external cavity semiconductor laser under different optical feedback intensity

基于等效腔理论,计及光线在外腔中多次反馈的情况后,从理论上研究了不同的反馈强度下,外腔半导体激光器(ECSL)的大信号调制特性。数值模拟的结果表明:当外部光反馈非常强或非常弱时,调制深度在一个较大的变化范围之内,ECSL的光子数呈现单周期变化规律,且峰值光子数随调制深度呈现单调上升的趋势;当外部光反馈处于中度反馈时,当调制深度取不同值时,ECSL的光子数呈现单周期、多周期甚至混沌现象。

Basing on the equivalent cavity theory, after taking into account the nmhiple reflections of light in external cavity, the large signal modulation characteris tics of the external cavity semiconductor laser （ECSL） has been theoretically investigated under different optical feedback intensity. The numerical simula- tions show that, when the external optical feedback is very strong or very weak and the modulation index varies in the large range,the photon number in the ECSL. is single- period, moreover the peak photon number of the ECSL increases monotonously with the increase of the modulation index; when the external optical feed- back is intermediate, the peak photon number of the ECSL behaves single period, multi - period or chaos for different modulation index.