High-speed integrated semiconductor micro-ring lasers with efficient off-axis parabolic reflectors

We report oil a novel mirror design for micro-ring semiconductor ring lasers that uses those mirrors to connect straight waveguide sections in a closed loop. The nearly parabolic mirrors are designed by ray-tracing to optimize their shape. The efficiency of the designs is verified with FDTD simulations, with a, simulated coupling efficiency of 98%. We have successfully fabricated devices based oil this design with an equivalent circular ring radius of 16 mu m. These devices operate in continuous wave at room temperature with a threshold current of only 22mA and all emission wavelength of 1.55 mu m.