利用包含透射光栅的外腔反馈结构,使半导体激光器阵列中各发光单元工作波长不相同,实现了各发光单元激射波长的啁啾。通过外腔镜使各个发光单元出射光束重叠及方向一致,实现半导体激光器阵列的光谱合束,从而提高半导体激光器的光束质量。采用前腔面镀有增透膜的激光器阵列实现功率为52.2 W的连续波激光输出,电-光转换效率达到47.9%,光谱线宽为15.17 nm。整个阵列输出光束的光参量积达到3.7 mm·mrad,与阵列中单个发光单元的光束质量基本一致。
The spectral beam combining with an array of high-power and high-efficiency diode lasers is reported by using a common external cavity which contains a transmission grating, while simultaneously forces each element to operate at different, but controlled wavelengths and forces the beams from all the elements to overlap and propagate in the same direction. Using the diode laser array with front-mirror surfaces coating with high transmittance films, a continuous-wave laser with output power of 52.2 W and electro-optical conversion efficiency of 47.9% is achieved. The spectral linewidth is about 15.17 nm. Beam parameter product (BBP) is 3.7 mm·mrad, which is the same as that of single element of the array.