Efficiently coupled microring circuit for on-chip cavity QED with trapped atoms

Abstract

We present a complete fabrication study of an efficiently coupled microring optical circuit tailored for cavity quantum electrodynamics with trapped atoms. The microring structures are fabricated on a transparent membrane with high in-vacuum fiber edge-coupling efficiency in a broad frequency band. In addition, a bus waveguide pulley coupler realizes critical coupling to the microrings at both of the cesium D-line frequencies, while high coupling efficiency is achieved at the cesium "magic"wavelengths for creating a lattice of two-color evanescent field traps above a microring. The presented platform holds promise for realizing a robust atom-nanophotonics hybrid quantum device.