在伴随信号的噪声为加性白噪声和大输入信噪比的前提下,采用小信号近似的方法,对微腔半导体激光器的自发发射因子调制进行了频域分析,得到了实际语音信号输入下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300～3400Hz,激光器的抗噪声性能随偏置电流变化出现振荡现象;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 factor modulation, by using small signal appoximatation, the signal-to-noise ratio (SNR) gain is derived in various parameters through frequency domain analysis against laser in the premise of large input SNR The results of numerical simulation show that when the pass band range of the band pass filter (BPF) is 300-3400 Hz, signal-to-noise ratio gain oscillates with bias current in the background of constant 1; while the pass band range of BPF increases to a certain degree, tunning-up modulating bias current and parameters of the cavity can improve the anti-noise properties of laser.