电负反馈半导体激光器半经典理论

本文建立了电负反馈半导体激光器的半经典速率方程模型,导出此类激光器的FM噪声功率谱密度,从而证明电负反馈技术可压窄激光器线宽。在反馈带宽之内激光器的频偏功率比(CPR)减小(1+H)倍,而带宽以外则不受影响,因此这类激光器可用作直接调制FSK相干传输系统光源。由于激光器直接频率调制时相位延迟的限制,l/f型FM噪声是限制谱线压缩的主要因素。 关键词：

A SEMICLASSICAL THEORY OF NEGATIVE FEEDBACK SEMICONDUCTOR LASER

In this paper, a semiclassical rate equation model has been established and the FM noise power spectrum calculated. We show that the spectral line width can be narrowed by the negative electrical feedback technique. Within the feedback loop bandwidth, the chirp-power-ratio (CPR) is reduced by a factor of 1+H, it shows that this kind of laser can be used as the light source in FSK coherent transmission system. Because of the direct modulation phase delay of the semiconductor laser, l/f-type FM noise is one of the important origin of the limitation, for linewidth reduction.