Lasing characteristics of integrated lasers with whispering-gallery mode microresonator

摘要

The characteristics of integrated lasers consisting of a Fabry-Perot (FP) cavity with one side connected to a whispering-gallery mode (WGM) microcavity are reported, in which the WGM microcavity acts as a resonant reflector for the FP cavity with its reflectivity capable of being modulated. The mode coupling between the WGM and FP mode would clamp the lasing mode around the wavelength of the WGM and suppress additional side modes. Single mode lasing with the side mode suppression ratio higher than 40 dB is realized for an integrated laser with the FP cavity directly connecting to one vertex of a square microcavity. The wavelength tunability is further demonstrated by varying the bias currents into the square cavity and the FP cavity regions. In addition to the lasing characteristics of single mode operation, we also report the high speed modulation characteristics of the integrated laser.