Tunable dual-wavelength picosecond pulse generation by the use of two Fabry-Pe/spl acute/rot laser diodes in an external injection seeding scheme

An attractive alternative to generate tunable dual wavelength pulses by external injection seeding of a gain-switched Fabry-Pe/spl acute/rot laser diode (FP-LD) is demonstrated. The external injection-seeding branch consists of only a FP-LD, a 3-dB coupler and two fiber Bragg gratings (FBGs). The two wavelengths can be selected and their spacing can be tuned by adjusting two FBGs. The output sidemode-suppression- ratio is better than 17 dB over a 10 nm wavelength tuning range. The whole system is simple and of low cost.