两种调制方式下微腔半导体激光器的抗噪声性能

Anti-noise Properties of Micro-cavity Semiconductor Laser for Two Modulation Methods

假定输入调制信号为实际语音信号 ,伴随语音信号的噪声为加性白噪声 ,在大输入信噪比前提下 ,对微腔半导体激光器的自发发射寿命调制、光子寿命调制两种调制方式进行了频域分析 ,得到了不同参数下的信噪比增益 .数值模拟的结果表明 ,如带通滤波器的通带范围取为 30 0～ 34 0 0Hz ,激光器的抗噪声性能基本不依赖于腔内参数 ;当带通滤波器的通带范围增大到一定程度 ,调整偏置电流和腔内参数可以实现两种调制下半导体激光器的高抗噪声性能 .

Supposing that input modulation signal is actual phonetic signal and its adjoint noise is additive white noise, for spontaneous emission lifetime modulation and photon lifetime modulation, we derive signal-to-noise ratio (SNR) in various parameters through frequency domain analysis against laser in the premiss of large input SNR. The results of numerical simulation show that if the pass band range of the band pass filter(BPF) is , the anti-noise properties of laser are approximately independent of parameters of the cavity; when the pass band range of BPF increases to a certain degree, modulating bias current and parameters of the cavity can improve the anti-noise properties of laser.