FIBER-GRATING EXTERNAL CAVITY LASERS

摘要

1.Introduction A fiber-grating external cavity laser (FG-ECL) is expected as a useful light source in optical fiber communication systems. A FG-ECL consists of a semiconductor optical amplifier (SOA) and a fiber with Bragg grating in the core. A fiber grating is formed by UV-induced periodic refractive index change in the core of a fiber,as shown in Fig. 1. Typical reflection spectrum of a fiber grating is also shown in Fig. 1. The rear facet of the SOA and the Bragg grating in the fiber form a laser cavity,as shown in Fig.2. Its oscillation wavelength is determined by a reflection peak wavelength of the fiber grating. As the wavelength controllability of fiber grating is in the order of subnanometer,precise wavelength control of lasers can be obtained. We have demonstrated two types of FG-ECLs for the dense WDM and erbium-doped fiber amplifier (EDFA) applications.