200-fs pulse generation from a GaInN semiconductor laser diode passively mode-locked in a dispersion-compensated external cavity

We have demonstrated passively mode-locked operation of a GaInN bisectional laser diode in a dispersion-compensated external cavity. With negative group velocity dispersion in the external cavity, we obtained femtosecond optical pulses after spectral filtering with a bandpass filter. The pulse duration was as short as 200 fs with a time-bandwidth product of 0.41. This is the shortest pulse ever reported for a mode-locked GaInN laser diode.