Mutual pulse injection-seeding scheme by the use of two Fabry–Pérot laser diodes for tunable dual-wavelength optical short-pulse generation

Two Fabry–Perot laser diodes, one being gain switched and the other dc biased, are used in a mutual pulse injection-seeding scheme for tunable dual-wavelength optical short-pulse generation. Wavelength selection and tuning are achieved by adjusting two fiber Bragg gratings and optical delay lines while a constant repetition frequency of 1.5053 GHz is maintained. An erbium-doped fiber amplifier is employed to enhance light intensity injected to the laser diode. The sidemode suppression ratio of the output pulses achieved is better than 25 dB over the wavelength-tuning range of 12.1 nm. The system is robust, flexible, and convenient for wavelength tuning.