Ultra-high-Q asymmetric microcavity optics

Confinement and manipulation of photons using microcavities have triggered intense research interest in both fundamental and applied photonics for more than two decades. Prominent examples are ultrahigh-Q whispering gallery microcavities which confine photons by means of continuous total internal reflection along a curved and smooth surface. The long photon lifetime, strong field confinement, and in-plane emission characteristics make them promising candidates for enhancing light-matter interactions on a chip. In the first part of this talk, I will introduce some representative photonics applications of ultrahigh-Q microcavities. In the second part, I will focuse on a new type of on-chip whispering gallery microcavity which supports both highly asymmetric far-field patterns and ultra-high-Q factors exceeding 100 million. These microcavities not only offer highly directional emission desired for various important application, but also hold great potential to test classical and quantum chaos because they behave like open billiard systems.