One- and two-dimensional photonic crystal micro-cavities in single crystal diamond

TL;DR

This paper presents a method to fabricate high-quality one- and two-dimensional photonic crystal micro-cavities in single-crystal diamond, enabling enhanced light-matter interactions for quantum technologies.

Contribution

It introduces a novel fabrication technique for diamond micro-cavities with high quality factors and demonstrates mode tuning and emission enhancement.

Findings

Quality factors up to 700 achieved

Cavity modes tuned to silicon-vacancy centers

Intensity enhancement of 2.8 times observed

Abstract

The development of solid-state photonic quantum technologies is of great interest for fundamental studies of light-matter interactions and quantum information science. Diamond has turned out to be an attractive material for integrated quantum information processing due to the extraordinary properties of its colour centres enabling e.g. bright single photon emission and spin quantum bits. To control emitted photons and to interconnect distant quantum bits, micro-cavities directly fabricated in the diamond material are desired. However, the production of photonic devices in high-quality diamond has been a challenge so far. Here we present a method to fabricate one- and two-dimensional photonic crystal micro-cavities in single-crystal diamond, yielding quality factors up to 700. Using a post-processing etching technique, we tune the cavity modes into resonance with the zero phonon line of an ensemble of silicon-vacancy centres and measure an intensity enhancement by a factor of 2.8. The controlled coupling to small mode volume photonic crystal cavities paves the way to larger scale photonic quantum devices based on single-crystal diamond.