中文摘要：

介绍了光栅外腔半导体激光器应用外部光栅实现选模和线宽压窄的基本原理，以及Littrow和Littman两种典型外腔结构和主要组成光学元件，讨论了主要性能表征参数包括调谐范围、激射线宽和边模抑制比等，分析了其关于稳定性的主要技术难点。在此基础上，详细综述了GaN基光栅外腔半导体激光器的国内外研究进展，主要集中在线宽、无跳模调谐范围和功率三个性能指标的优化上，特别提及了厦门大学研究小组的工作进展。最后讨论了其在高精度光谱测试、气体探测和大容量全息数据存储中的应用，并且列举了铟原子的光谱测试和NO气体探测。

英文摘要：

The fundamental principles of mode selection and wide-line narrowing by using the external grating for the grating external cavity semiconductor lasers are introduced, and the two typical external cavity structures of Littrow-type and Littman-type and main optical components are introduced. The main performance characterization parameters, including tuning range, lasing linewidth, side-mode suppression ratio and so on, are discussed. And the main technical difficulties of the stability are analyzed. On this basis, the research progresses both at home and abroad of the GaN-based grating-coupled external cavity semiconductor lasers are reviewed in detail, focusing on the optimization for three performance indexes of the linewidth, mode-hop-free tuning range and power. The research progress of the research group of Xiamen University is also mentioned. Finally, the applications of the GaN-based grating-coupled external cavity semiconductor laser on the high-precision spectral measurement, gas detection and high capacity holographic data storage are discussed, and the indium atom spectrum test and the NO gas detection are listed.