Hybrid and Passive Mode-Locking of a Monolithic Two-Section MQW InGaN/GaN Laser Diode
We report the first hybrid mode-locking of a monolithic two-section multiple quantum well InGaN based laser diode. This device, with a length of 1.5 mm, has a 50-mu m-long absorber section located at the back facet and generates a continuous stable 28.6 GHz pulse train with an average output power of 9.4 mW at an emission wavelength of 422 nm. Under hybrid mode-locking, the pulse width reduces to 4 ps, the peak power increases to 72 mW, and the microwave linewidth reduces by 13 dB to <500 kHz. We also observe the passive mode-locking with pulse width and peak power of 8 ps and 37 mW, respectively.