A wavelength tunable passively mode-locked semiconductor laser source
of subpicosecond pulses is demonstrated. The system includes a two-sec
tion multiple-quantum-well laser which is coupled to an external grati
ng for tuning and is followed by an external grating pair for pulse co
mpression. A tuning range of 16 nm around 846 nm is obtained, resultin
g in compressed pulse widths as short as 260 fs and pulse widths short
er than 600 fs for all wavelength values within this tuning range. Tim
e bandwidth products are one to two times the transform limit.