Single-Frequency Tunable External-Cavity Semiconductor Lasers Emitting at 1550 nm

We report the results of fabrication works on single-frequency tunable semiconductor laser modules for a wavelength of 1550 nm, with an external cavity being based on fiber Bragg gratings formed in a single-mode fiber. Tuning of the radiation wavelength using a piezoceramic element is considered. The laser modules are capable of generating dynamically stable single-frequency radiation with side mode suppression of more than 40 dB, a lasing line width of 100 kHz, and an output optical power of higher than 50 mW. The wavelength tuning of the emission spectrum of the laser module is 2 nm.