Telecommunication-wavelength two-dimensional photonic crystal cavities in a thin single-crystal diamond membrane

TL;DR

This paper reports the development of high-quality two-dimensional photonic crystal cavities in a thin single-crystal diamond membrane operating at telecommunication wavelengths, enabling advanced on-chip diamond nanophotonics.

Contribution

The authors demonstrate a fabrication method for high-Q photonic crystal cavities in diamond membranes at telecommunication wavelengths, with potential for integrated nanophotonic devices.

Findings

Achieved cavity Q factors up to ~1800 in the telecommunication range.

Fabricated fully suspended photonic crystal cavities in a 300 nm diamond membrane.

Operated over a broad wavelength range spanning 1360-1470 nm.

Abstract

We demonstrate two-dimensional photonic crystal cavities operating at telecommunication wavelengths in a single-crystal diamond membrane. We use a high-optical-quality and thin (~ 300 nm) diamond membrane, supported by a polycrystalline diamond frame, to realize fully suspended two-dimensional photonic crystal cavities with a high theoretical quality factor of ~ $8\times10^6$ and a relatively small mode volume of ~2$({\lambda}/n)^3$. The cavities are fabricated in the membrane using electron-beam lithography and vertical dry etching. We observe cavity resonances over a wide wavelength range spanning the telecommunication O- and S-bands (1360 nm-1470 nm) with Q factors of up to ~1800. Our method offers a new direction for on-chip diamond nanophotonic applications in the telecommunication-wavelength range.