带非吸收窗口的大功率657nm半导体激光器

High Power 657nm Laser Diodes with NonAbsorbing Windows

在激光器腔面处制作非吸收窗口（NAW）可以有效地减少光吸收，防止激光器过早出现光学灾变损伤（COD），是提高大功率半导体激光器的功率特性的重要手段之一。采用金属有机化学气相沉积（MOCVD）技术二次外延生长了大功率657nm红光半导体激光器结构，通过闭管扩散Zn的方法在腔面附近制作了非吸收窗口。实验发现扩散温度550℃，扩散时间20min时，得到的非吸收窗口最为有效，激光器连续工作的无扭折输出功率大于100mW，超过常规的无窗口结构激光器的最大输出功率的两倍，激光器的斜率效率提高了23％。测量该类器件的温度特性发现，环境温度为20～70℃时，其输出功率均可大于50mW，计算得到激光器的特征温度约为89K，波长增加率约为0.24nm／℃。

To fabricate nonabsorbing windows （NAWs） near the cavity facets can reduce the light absorption and prevent early catastrophic optical damage （COD） of the cavity facets, which is an important skill in improving the output characteristics of the high power laser diode （LD）. High power 657 nm red LD wafer was epitaxied by a two- step metalorganic chemical vapor deposition （MOCVD） technique, and NAWs were fabricated by Zn impurity diffusion using a closed ampoule method. NAWs fabricated at a diffusion temperature of 550℃ and a diffusion time of 20 rain are very effective in improving the LD＇s performance. Stable fundamental mode continuous wave operation is achieved at up to 100 mW without any kinks, which is three times of the maximum output power of conventional LD without the NAWs. The slope efficiency of the LD is also improved about 23G than that of the conventional LD. At ambient temperature of 20-70℃, the maximum outputs of the LDs are all over 50 mW, and the calculated characteristic temperature and the lasing wavelength increment are about 89 K and 0.24 nm/℃, respectively.