Three-guide coupled rectangular ring lasers with total internal reflection mirrors

Abstract

The lasing characteristics of three-guide coupled ring lasers using the self-aligned total internal reflection (TIR) mirrors were investigated numerically and experimentally. The rectangular laser cavity consists of four low loss TIR mirrors and an output coupler made out of passive three coupled waveguides. Two different lasers having active section lengths of 250 and 350 mu m and total cavity lengths of 580 and 780 pm are fabricated. For both devices lasing thresholds of 38 mA is obtained at room temperature and under CW operation. Lasing is predominantly single mode with the side mode suppression ratio better than 20 dB.