Microgear laser

Abstract
A microlaser, microgear, composed of a microdisk and a rotationally symmetric Bragg grating is described. A GaInAsP–InP device with μm radius was fabricated and the room-temperature continuous-wave operation was obtained by photopumping with a low threshold of 17 μW. The experiment clearly demonstrated that the Q factor in a microdisk was enhanced by the microgear due to the minimization of the radiation field. Resonant spectra showed some unique mode characteristics influenced by an elliptical cavity. These results suggest a potential of advanced engineering of whispering-gallery-mode laser with a photonic crystal, the generalized Bragg grating.