808nm大功率无铝有源区非对称波导结构激光器

808 nm High-Power Lasers with Al-Free Active Region with Asymmetric Waveguide Structure

采用分别限制非对称波导结构,将光场从对称分布变为非对称分布,降低了载流子光吸收损耗,并允许p型区具有更高的掺杂水平,从而使器件电阻降低。对GaAsP/GaInP张应变单量子阱（SQW）非对称波导结构激光器的光场特性进行了理论分析,设计了波导层厚度,并制作了波长为808 nm的无铝有源区大功率半导体激光器.器件综合特性测试结果为：腔长900μm器件的阈值电流密度典型值为400 A/cm^2,内损耗低至1.0 cm^-1;连续工作条件下,150μm条宽器件输出功率达到6 W,最大斜率效率为1.25 W/A.器件激射波长为807.5 nm,平行和垂直结的发散角分别为3.0°和34.8°。20～70℃范围内特征温度达到133 K。结果表明,分别限制非对称波导结构是降低内损耗,提高大功率半导体激光器特性的有效措施。

Shifting of the optical mode from symmetric distribution to asymmetric distribution by separate confinement asymmetric waveguide structure reduces optical absorption loss by carriers,and permits higher doping of the p side to reduce resistance.Based on the theoretical analysis for the optical field distribution characteristics of GaAsP/GaInP tensile-strained single quantum well（SQW） lasers with asymmetric waveguide,the thickness of waveguide layers was optimized,and a high-power semiconductor laser with Al-free active region was fabricated and studied experimentally.For a 900 μm cavity length device,the typical threshold current density is 400 A/cm^2,and a low internal loss around 1.0 cm^-1 is achieved.Under continuous wave（CW） operation condition,150 μm aperture devices achieve a CW output power of 6 W,the maximum slope efficiency of the prepared devices is 1.25 W/A,and the lasing wavelength is 807.5 nm.Horizontal and vertical far-field divergence angles are 3.0° and 34.8°,respectively.The characteristic temperature of the laser in the range of 20～70 ℃ is estimated to be about 133 K.Separate confinement asymmetric waveguide structure is proven to be an impactful method for reducing optical loss and improving the characteristics of high power diode lasers.