高温高斜率效率1060nm单模半导体激光器

High-temperature High-slope-efficiency 1060nm Single-mode Semiconductor Laser

摘要:

nm半导体激光器在高能激光系统种子源、空间激光雷达等领域具有广泛的应用,受限于砷化镓体系InGaAs量子阱材料大应力,在1060nm波段激光器外延生长缺陷密度较高,且由于目前该波段激光器结构设计普遍采用窄波导结构,腔内损耗和非辐射复合水平较高,激光器斜率效率较低,高温特性较差。传统InGaAs压应变量子阱势垒高度较低加剧了激光器的高温特性劣化。文章通过优化激光器外延生长条件并采用应变补偿量子阱结构和厚N包层结构,精确控制材料应力和势垒高度,降低腔内损耗,减小远场发散角,研制出了一种高性能1060nm单模半导体激光器,斜率效率在85℃时依然超过0.9W/A。此外,通过引入分布式反馈激光器悬浮掩埋光栅结构实现了激光器波长锁定,斜率效率超过0.7W/A。

Abstract:

Currently, 1060nm semiconductor lasers are widely applied in areas that include space LiDAR and high-energy laser systems. Because of the high stress of InGaAs on a GaAs substrate, 1060nm semiconductor lasers usually have a large number of defects. In addition, 1060nm semiconductor lasers always have a thin waveguide layer for a large confinement factor. This produces a large cavity loss and non-radiation combination, which leads to poor slope efficiency and high-temperature characteristics. Moreover, the conventional GaAs barrier cannot effectively confine the carriers in the quantum well, which degrades its performance when the operating temperature is high. This study optimized the growth conditions and applied stress-compensated quantum wells to effectively control the stress and barrier height. Enlarging the N cladding thickness also reduced the loss in the cavity. Consequently, we invented a high-performance 1060nm semiconductor laser, which had a slope efficiency as high as ever recorded (0.9W/A) at both room and high temperature. Through the buried DFB grating, it also realized operation in a single longitudinal mode with a high slope efficiency of 0.7W/A.