A vertically-loaded diamond microdisk resonator spin-photon interface

TL;DR

This paper introduces a novel diamond microdisk resonator design that significantly enhances the collection efficiency of spin-photon interfaces, facilitating quantum communication and sensing applications.

Contribution

The paper presents a new vertically-loaded diamond microdisk resonator optimized for high Purcell enhancement and efficient photon collection from NV centers.

Findings

Achieves a Purcell factor of 172.

Collects 39% of emitted light within NA of 0.6.

Total external collection efficiency of 0.33.

Abstract

We propose and optimize a vertically-loaded diamond microdisk resonator (VLDMoRt) coupled to a nitrogen-vacancy (NV) center in diamond for efficient collection of zero-phonon-line emission into low numerical aperture ($\text{NA}$) free-space modes. The VLDMoRt achieves a Purcell enhancement of 172 with $39\%$ of the emitted light collected within a $\text{NA}$ of 0.6, leading to a total external spin-photon collection efficiency of 0.33. As the design is compatible with established nanofabrication techniques and couples to low-NA modes accessible by cryogenic free-space optical systems, it is a promising platform for efficient spin-photon interfaces based on diamond quantum emitters.