Fabrication of Triangular Nanobeam Waveguide Networks in Bulk diamond Using Single-Crystal Silicon Hard Masks

TL;DR

This paper presents a scalable method for fabricating high-quality photonic crystal cavities and waveguide networks in bulk diamond using single-crystal silicon masks and angular dry etching, enabling advanced integrated photonics.

Contribution

The authors introduce a novel fabrication technique combining silicon hard masks and angular etching to create diamond photonic structures with high Q-factors and low loss.

Findings

Achieved photonic crystal cavities with Q up to 3,000.

Demonstrated low transmission loss of 0.05 dB in waveguides.

Successfully fabricated structures in the visible spectrum.

Abstract

A scalable approach for integrated photonic networks in single-crystal diamond using triangular etching of bulk samples is presented. We describe designs of high quality factor (Q=2.51x10^6) photonic crystal cavities with low mode volume (Vm=1.062x({\lambda}/n)^3), which are connected via waveguides supported by suspension structures with predicted transmission loss of only 0.05 dB. We demonstrate the fabrication of these structures using transferred single-crystal silicon hard masks and angular dry etching, yielding photonic crystal cavities in the visible spectrum with measured quality factors in excess of Q=3x103.