Monolithic mode locked 1.3 mu m laser with active waveguide and saturable absorber

1.3 mu m GaInAsP lasers were integrated with active waveguides and satirable absorbers to form arrays of monolithic devices. These devices have low threshold currents, and long integrated waveguides have led to picosecond pulse widths at a 15-GHz repetition rate. The integrated active waveguides decrease the effective coupling losses from laser to integrated cavity, and the saturable absorber provides pulse shortening by both active and passive mode locking. Arrays of six monolithic devices were fabricated from semi-insulating channeled substrate buried heterostructure 1.3 mu m GaInAsP laser material. Microwave measurements of the frequency response of these devices show a very large peak at 15 GHz which is one over the round trip time of the device. This peak at 15 GHz was measured to be 12 dB below the response at 50 MHz, while away from the peak the response falls by over 27 dB. This indicates a strong feedback from the integrated cavity, a characteristic of active waveguides.