Characterization of 1.55-μm pulses from a self-seeded gain-switched Fabry-Pérot laser diode using frequency-resolved optical gating

The intensity and frequency chirp of picosecond pulses from a self-seeded gain-switched Fabry-Perot laser diode have been directly measured using the technique of frequency-resolved optical gating. Measurements over an output sidemode suppression ratio (SMSR) range of 15-35 dB show that higher SMSR's are associated with an increasingly linear frequency chirp across the output pulses. This complete pulse characterization allows the conditions for optimum pulse compression to be determined accurately, and indicates that transform-limited, pedestal free pulses can be obtained at an SMSR of 35 dB