We designed a single-frequency green laser system that can deliver a 60-mW frequency-tunable single-longitudinal-mode laser beam, having a 6.5 MHz linewidth at around 519 nm. An external cavity diode laser can provide a wavelength-tunable single frequency laser beam, but its output power is limited. Therefore, an injection-locked laser was designed with a Fabry–Perot type green InGaN laser diode in an external Littrow-type cavity as the master laser and another laser diode of the same model as the slave laser. Injection locking can effectively enhance the output power and narrow the linewidth of the master laser. We found that the injection locking occurred at longitudinal mode matching between the master laser and slave laser diodes, which is located at a specific frequency for a periodical applied current. The side peaks of the injection locking due to the transverse mode mismatching were recorded and analyzed.

中文翻译：

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注入锁定绿色 InGaN 二极管激光器

我们设计了一种单频绿色激光系统，可以提供 60 mW 频率可调的单纵模激光束，在 519 nm 左右具有 6.5 MHz 的线宽。外腔二极管激光器可以提供波长可调的单频激光束，但其输出功率有限。因此，设计了一种注入锁定激光器，在外部利特罗型腔中使用法布里-珀罗型绿色 InGaN 激光二极管作为主激光器，另一个同型号的激光二极管作为从激光器。注入锁定可以有效提高输出功率，缩小主激光器的线宽。我们发现注入锁定发生在主激光器和从属激光二极管之间的纵向模式匹配时，它位于周期性施加电流的特定频率。