Mode Investigation for Hybrid Microring Lasers With Sloped Sidewalls Coupled to a Silicon Waveguide

Hybrid AlGaInAs/InP microring lasers with sloped sidewalls coupled to a silicon waveguide are investigated numerically and experimentally. The mode field distribution deviations for the microring resonator with the sloped sidewalls at different tilting angles are simulated by a 3-D finite-difference time-domain technique. Obvious enhancements of output coupling to the silicon waveguide and the active region optical confinement factor can be expected as the microresonator has a trapezoidal shape. A hybrid microring laser with a radius of 19 μm and a width of 2 μm is fabricated with the laser wafer bonded on a silicon-on-insulator wafer using the divinylsiloxane-benzocyclobutene (DVS-BCB) adhesive bonding technique. Continuous-wave electrically injected operation is realized at a tilting angle of -6° with the threshold currents of 7.8 and 9 mA at 12 °C and 22 °C. In addition, for a hybrid microring laser with a radius of 29 μm and a ring width of 2.5 μm, continuous-wave electrical operation up to 50 °C is achieved.