Competing mode suppression ratio of electrically wavelength tunable self-seeded lasers

The competing mode suppression ratio of electrically wavelength tunable self-seeded semiconductor laser systems is investigated experimentally and theoretically for varying length differences between the feedback cavities, It is shown that for length differences more than 10 mm, the selected mode is dominating by more than 15 dB the unwanted mode. The buildup of stable single-mode emission takes less than five to ten round-trips for these length differences. Thus, switching frequencies of up to 100 MHz between the modes can be achieved.