在相干光通信中,需要窄带且单波频的光源。作为满足这种要求的一种光源,可以举出环形激光器。据报道,在把半导体作为增益介质的环形激光器中,使用了大型反射镜和透镜以及光纤作光源。不过,上述的环形激光器存在着透镜反射和谐振腔长之类的缺点。本文介绍一种激光光源,它是利用平 In coherent optical communication, a narrow-band and single-wave frequency light source is needed. As a light source satisfying such a requirement, a ring laser can be cited. It has been reported that in a ring laser using a semiconductor as a gain medium, a large mirror and a lens and an optical fiber are used as a light source. However, the ring laser described above suffers from the drawbacks of lens reflection and resonant cavity length. This article describes a laser light source, which utilizes flat