Experimental demonstration of a hybrid III–V-on-silicon microlaser based on resonant grating cavity mirrors

We present the experimental demonstration of a novel class of hybrid III–V-on-silicon microlasers. We show that by coupling a silicon cavity to a III–V waveguide, the interaction between the propagating mode in the III–V waveguide and the cavity mode in the silicon resonator results in high, narrowband reflection back into the III–V waveguide, forming a so-called resonant mirror. By combining two such mirrors and providing optical gain in the III–V wire between these two mirrors, laser operation can be realized. This optically pumped device measures 55 by 2 μm, requires microwatt-level threshold pump power, and shows single-mode laser emission with a side-mode suppression ratio of up to 39 dB.