915 nm宽条形半导体激光器输出特性

为了研究温升对915 nm宽条形应变量子阱半导体激光器输出特性的影响,搭建了基于半导体制冷片(TEC)的双向温控平台对其进行了测试。首先,改变激光器的外表面温度,测量其在不同注入电流时的光功率和波长,并利用CCD相机测量其慢轴发散角。然后,利用计算机仿真软件对激光器的工作状态进行稳态模拟,从而获得了其对应的热分布情况,通过将模拟得到的数据与实验测量的结果进行比较,获得了两者趋于一致的结论:当热功率从2.1 W升高至20.0 W时,慢轴发散角从2.6°增大至5.0°,同时波长发生红移,热透镜焦距减小;激光器波长随温度变化关系的系数约为0.4 nm/℃,器件热阻为1.5 K/W。因此,为了同时获得高的输出功率和稳定的输出波长,有必要将激光器外表面温度精确控制在某一数值,否则波长将会发生漂移;此外,在设计制作高功率半导体激光器时,通过适当增加条宽并采用散热良好的封装结构,可以减小对慢轴发散角的影响。

Output Characteristics of 915 nm Wide Strip Semiconductor Lasers

To investigate the effect of temperature rise on the output characteristics of the 915 nm wide strip strain quantum well semiconductor laser,a TEC-based bi-directional temperature control platform was built to test it.First,by changing the temperature of the outer surface of the laser,the power and wavelength of the output beam at different injection currents are measured,and the slow axis divergence angle is measured by a CCD camera.Then,the computer simulation software was used to simulate the working state of the laser,and its steady state heat distribution was obtained.By comparing the simulation results with the measured data,the results tend to be consistent.When the thermal power was increased from 2.1 W to 20.0 W,the slow axis divergence angle increased from 2.6 degrees to 5.0 degrees,and the wavelength of the output light was red-shifted,and the thermal lens focal length of the laser was reduced.The laser has a wavelength temperature variation coefficient of about 0.4 nm/℃,and a thermal resistance of 1.5 K/W.Therefore,in order to obtain high output power and stable output wavelength at the same time,it is necessary to accurately control the temperature of the outer surface of the laser to a certain value,otherwise the wavelength will drift.In addition,when designing and manufacturing a high-power semiconductor laser,the influence on the slow axis divergence angle can be reduced by appropriately increasing the strip width and using a heat-dissipating package structure.