The external quantum efficiency of semiconductor ring lasers has been significantly improved by introducing output couplers that couple more light out of the ring cavity. Improvements from 10% and 16% to 14% and 27% of a comparable single 2×2 MMI coupler device were achieved by using 3×3 multimode interference (MMI) couplers and dual 2×2 MMI couplers, respectively. A further increase to the value of 33% (or 2 times that of the previous devices) was obtained by AR coating the output facets of the dual 2×2 MMI coupler devices. These devices also provided four output beams as required in an integrated optical time domain multiplexing (OTDM) system.
|Translated title of the contribution||Multiple output semiconductor ring lasers with high external quantum efficiency|
|Pages (from-to)||19 - 22|
|Number of pages||4|
|Journal||IEE Proceedings: Optoelectronics|
|Publication status||Published - Feb 1997|