大功率体光栅外腔半导体激光器的输出特性

宽条形大功率半导体激光器(LD)存在光谱温漂系数大、光谱宽度宽的缺点,为了改善宽条形大功率半导体激光器的光谱特性,采用一种体光栅(VBG)离轴外腔方法实现了宽条形大功率半导体激光器光谱特性的明显改善和高效率工作.宽条形半导体激光器的外腔结构主要包括激光器输出光束的快、慢轴准直光学透镜和离轴放置的体光栅.宽条形半导体激光器的激射条宽为100μm,当激光器工作电流为4.0 A时,外腔激光器的输出功率高达3.4 W,斜率效率为1.0 W/A,光谱宽度由自由出射条件下的2~3 nm减少为0.2 nm,峰值波长的温漂系数小于0.015 nm/℃.

Characteristics of High Power Volume-Bragg-Grating External Cavity Semiconductor Lasers

High wavelength shift coefficient varying with temperature and broad spectrum width are disadvantages of the output properties of high power broad-area semiconductor lasers. For improving the output spectral properties of broad-area semiconductor lasers, a volume-Bragg-grating (VBG) off-axis external cavity method was adopted with satisfied effect on spectrum and slope efficiency. The external cavity laser composes of a broad-area stripe semiconductor laser with fast-axis and slow axis beam collimation, and a VBG positioned off-axis. The broad-area stripe semiconductor laser has an emission width of 100 μm. High power output is achieved with 3.4 W at working current with 4.0 A. The slope efficiency is 1.0 W/A, and a narrower output spectrum of 0.2 nm width is realized compared with free output spectrum width of 2～3 nm. The wavelength shift coefficient varying with temperature is less than 0.015 nm/℃.