采用射线法,计及增益随波长的变化,导出了光纤光栅外腔半导体激光器输出谱及输出功率的表达式。结合载流子速率方程,对外腔半导体激光器的输出谱的精细结构以及P-I 特性进行了数值模拟研究。结果表明：光纤光栅外腔的输出谱在反射带宽内呈现出多峰结构,随着前端面反射率越小,输出谱相应地比较稳定;P-I 特性曲线抖动越来越小,趋于线性变化。

Based on the ray tracing method,considering the gain distribution with wavelength,the expressions of the output spectrum and output power of the fiber grating external cavity semiconductor lasers (FGECL) are deduced firstly. Combining with carrier rate equation,the fine structure of output spectrum and output power are numerically simulated. The results show that,in the reflective band width of grating the multi-peak structure appears,and the output spectrum becomes firmer with the decrease of the front facet reflectivity. The P-I characteristic of FGECL has been investigated. With the decrease of the front facet reflectivity,the fluctuation of the output power tends minimized and the P-I curve becomes generally a straight line.