Picosecond Pulse Generation Using A Saturable Absorber Section Of Grating-Coupled Surface-Emitting Laser

We report on a passively and hybridly mode-locked grating-coupled surface-emitting laser (GCSEL) using the unpumped section of the GCSEL as a saturable absorber. We obtain 8.8-ps full-width at half-maximum (FWHM) autocorrelation pulses in passive mode-locked operation and an FWHM pulse duration of 3.4 ps in hybrid mode-locked operation, which are the shortest pulses from a GCSEL external cavity. With hybrid mode-locking, a peak power of 0.26 W and a spectral bandwidth of 0.6 nm are obtained. These results demonstrate the potential of multisegment GCSELs in ultrashort pulse generation. © 2005 IEEE