Variable delay dual wavelength picosecond optical pulse generation using an actively mode-locked multichannel grating cavity laser

Two optical pulse trains are generated at different wavelengths with a programmable delay between them, using active mode-locking of a multichannel grating cavity laser. For a channel separation of 2.2 nm, pulses with a duration of 60 ps and with a spectral width of 11.6 GHz have been obtained at a repetition rate of 1.78 GHz. The pulse width and power are stable to within 6%, irrespective of delay for a relatively wide range of dc bias conditions.