Broadband light extraction from near-surface NV centers using crystalline-silicon antennas

TL;DR

This paper demonstrates a silicon antenna design that significantly improves broadband light extraction from shallow NV centers in diamond, enhancing photon collection efficiency without damaging the diamond surface.

Contribution

The study introduces a silicon antenna approach for efficient broadband photon extraction from NV centers, avoiding surface damage and enabling practical quantum emitter applications.

Findings

~17 times photon collection in simulations

~9 times enhancement observed experimentally

Effective for broadband light extraction from NV centers

Abstract

We use crystalline silicon (Si) antennas to efficiently extract broadband single-photon fluorescence from shallow nitrogen-vacancy (NV) centers in diamond into free space. Our design features relatively easy-to-pattern high-index Si resonators on the diamond surface to boost photon extraction by overcoming total internal reflection and Fresnel reflection at the diamond-air interface, and providing modest Purcell enhancement, without etching or otherwise damaging the diamond surface. In simulations, ~17 times more single photons are collected from a single NV center compared to the case without the antenna; in experiments, we observe an enhancement of ~9 times, limited by spatial alignment between the NV and the antenna. Our approach can be readily applied to other color centers in diamond, and more generally to the extraction of light from quantum emitters in wide-bandgap materials.