Output Power of III-V Injection Microdisk and Microring Lasers

Technological progress makes it possible to significantly reduce the size of semiconductor laser emitters to microscales and sizes commensurate with the emission wavelength. Extreme laser miniaturization can be achieved using disk or ring resonators supporting high-Q whispering gallery modes (WGM). WGM lasers are interesting not only due to small sizes (small mode volume) but also for their long times of light-matter interaction, unique capabilities of sensing and studying of quantum chaos and so on. On the other hand, small losses for the output of emission in high-Q resonators can negate the practical benefits of the laser or even completely hide the peculiarities of the light physics inside the cavity. In this review, we attempted to summarize the published data on the achieved optical output power in different III-V injection microlasers and analyzed the key characteristics that limit the maximum output power, especially influence of the active region self-heating at cw operation and impeded light extraction out of WGM cavities. We compared various III-V materials and fabrication methods developed for improving emission output. We also observe very low relative intensity noise in microdisk lasers and harmonics of the resonance frequency in the relative intensity noise spectrum.