低温808 nm高效率半导体激光器

Low Temperature 808 nm High Efficiency Semiconductor Laser

为了提高低温工作环境下808 nm半导体激光器的输出特性,深入研究了电光转换效率的温度特性。结合载流子泄漏抑制和器件串联电阻的优化考虑,从理论上深入分析了有源区量子阱内的载流子限制现象,提出针对低温工作环境下的势垒高度及相应的量子阱结构设计方法,包括势垒层的材料组分、厚度等重要参数的优化,极大地改善了器件在低温工作环境下的性能。采用优化后的外延结构,制备了腔长2 mm的半导体激光巴条。在工作温度-50℃、注入电流为600 A时,巴条输出功率达到799 W,电光转换效率为71%,斜率效率为1.34 W/A;注入电流为400 A时,器件达到最高电光转换效率73.5%,此时的载流子限制效率约为99%,串联电阻为0.43 mΩ;在-60~60℃温度范围内,中心波长随温度的漂移系数为0.248 nm/℃。

In order to improve the performance of 808 nm semiconductor laser operating at low temperature,the temperature dependence of electro-optical conversion efficiency was studied.Combining the suppression of carrier leakage and the optimization of the series resistance,the carrier confinement phenomenon in the quantum well was analyzed theoretically.Moreover,the potential barrier height and the corresponding quantum well structure for low temperature operating were proposed,including the optimization of important parameters such as the material composition and thickness of the barrier layer,which showed significant benefit for operation under low temperature.Basing on the optimized epitaxial structure,semiconductor laser bars with a cavity length of 2 mm were fabricated.Under the temperature of-50℃,an electro-optical conversion efficiency of 71%was demonstrated with a slope efficiency of 1.34 W/A and an injection current of 600 A.Record high electro-optical conversion efficiency of 73.5%was reached with the injection current of 400 A,while the carrier confinement efficiency was as high as 99%,and the series resistance was as low as 0.43 mΩ.In the temperature range of-60-60℃,the shift coefficient of the center wavelength with temperature was about 0.248 nm/℃.