Triangular nanobeam photonic cavities in single crystal diamond

TL;DR

This paper reviews diamond photonics and introduces a novel triangular nanobeam cavity in single crystal diamond, demonstrating improved confinement and collection efficiency with potential for high-Q quantum applications.

Contribution

It presents the design, fabrication, and characterization of a new triangular nanobeam cavity in diamond, achieving moderate Q factors and modeling higher Q designs for quantum photonics.

Findings

Nanobeam cavity with Q ~220 demonstrated

Good agreement between experimental results and FDTD simulations

Potential for high-Q cavities with Q=22,000 modeled

Abstract

Diamond photonics provides an attractive architecture to explore room temperature cavity quantum electrodynamics and to realize scalable multi-qubit computing. Here we review the present state of diamond photonic technology. The design, fabrication and characterization of a novel triangular cross section nanobeam cavity produced in a single crystal diamond is demonstrated. The present cavity design, based on a triangular cross section allows vertical confinement and better signal collection efficiency than that of slab-based nanocavities, and eliminates the need for a pre-existing membrane. The nanobeam is fabricated by Focused-Ion-Beam (FIB) patterning. The cavity is characterized by a confocal photoluminescence. The modes display quality factors of Q ~220 and are deviated in wavelength by only ~1.7nm from the NV- color center zero phonon line (ZPL). The measured results are found in good agreement with 3D Finite-Difference-Time-Domain (FDTD) calculations. A more advanced cavity design with Q=22,000 is modeled, showing the potential for high-Q implementations using the triangular cavity design. The prospects of this concept and its application to spin non-demolition measurement and quantum computing are discussed.