Dual Mode Microcavity Semiconductor Lasers
Dual mode microcavity semiconductor lasers are investigated for potential applications in photonic microwave and optical frequency comb (OFC) generation. By regulating whispering gallery modes (WGMs) in square microcavities, dual mode lasing is achieved with frequency intervals ranging from tens to hundreds of gigahertz. In the square microcavities, the fundamental and first order transverse WGMs have spatially separated field distributions, which allow stable dual transverse mode lasing with mode intervals inversely proportional to the cavity areas. Dual transverse mode square microcavity lasers are experimentally demonstrated with frequency intervals ranging from ~35 to ~150 GHz. Photonic microwaves and OFCs are successfully generated based on the dual mode square microcavity lasers. To enhance the transverse mode intervals, circular side square microcavity lasers with a square hole in the center are proposed and demonstrated, and dual transverse mode lasing with a frequency interval up to ~0.56 THz is obtained. Furthermore, a square Fabry Perot coupled cavity microlaser is demonstrated to increase the output power and introduce an additional degree for manipulating the lasing modes. Dual mode lasing is realized with a frequency interval of ~0.5 THz, a single mode optical fiber coupled power of ~3 mW, and a wavelength tuning range of ~10 nm.
IEEE Journal of Selected Topics in Quantum Electronics