Chirp control and broadband wavelength-tuning of 40-GHz monolithic actively mode-locked laser diode module with an external CW light injection

Chirp control behaviors of a 40-GHz monolithic actively mode-locked laser diode (MLLD) with an external continuous wave (CW) light injection were experimentally investigated in detail. Large frequency chirping of the Fabry-Pe/spl acute/rot-type MLLD was found to be reduced by the CW light input with sufficient power. Broad-band wavelength tuning over 60 nm was also successfully achieved using the external CW light as a wavelength-selection element. Optical short pulses shorter than 4 ps were generated leaving small frequency chirping, low timing jitters less of than 0.2 ps, and low relative intensity noise values of less than -130 dB/Hz over the whole tuning range from 1530 to 1592 nm, almost covering both the C and the L bands in the wavelength region of optical communication systems.