Wavelength tuning in self-seeded gain-switched Fabry-Perot laser diode with Moire grating

The authors propose a simple method for generating wavelength-tunable singl emode picosecond pulses at a fixed repetition rate. This method is based on self-seeding a Fabry-Perot (FP) laser diode hating a fibre external cavity formed by a Moire grating with a proper channel spacing. Stepwise waveleng th tuning over a large range can be achieved by changing the FP cavity roun dtrip phase shift, and fast electrical tuning is possible by incorporating a phase-control section into the FP cavity. By using a two-channel Moire gr ating and a temperature-controlled FP laser diode, tuning of picosecond pul ses at a repetition rate of similar to 2GHz between two wavelengths similar to 11nm apart is demonstrated. A sidemode suppression ratio of > 25dB has been achieved.