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

TL;DR

This paper demonstrates a fabrication process for a microring circuit optimized for cavity QED with trapped atoms, enabling efficient atom-photon interactions on a chip.

Contribution

It introduces a complete fabrication method for a microring circuit with high coupling efficiency and dual-frequency operation for quantum atom trapping and interaction.

Findings

High in-vacuum fiber edge-coupling efficiency across a broad frequency band

Critical coupling at cesium D-line frequencies achieved with pulley coupler

High coupling efficiency at cesium 'magic' wavelengths for atom trapping

Abstract

We present a complete fabrication study of an efficiently-coupled microring optical circuit tailored for cavity quantum electrodynamics (QED) 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 promises for realizing a robust atom-nanophotonics hybrid quantum device.