Design of microcavities in diamond-based photonic crystals by Fourier- and real-space analysis of cavity fields

TL;DR

This paper introduces a method for designing high-quality diamond-based photonic crystal microcavities using Fourier and real-space analysis, achieving record quality factors and improving silicon cavity designs.

Contribution

It presents a novel approach combining Fourier and real-space analysis for optimizing microcavity structures in diamond and silicon, enhancing quality factors and modal volumes.

Findings

Achieved Q factors up to 320,000 in diamond microcavities.

Improved silicon microcavity design with a threefold increase in Q.

Developed a simple predictive model for material absorption effects.

Abstract

We present the design of two-dimensional photonic crystal microcavities in thin diamond membranes well suited for coupling of color centers in diamond. By comparing simulated and ideal field distributions in Fourier and real space and by according modification of air hole positions and size, we optimize the cavity structure yielding high quality factors up to Q = 320000 with a modal volume of V = 0.35 (lambda/n)^3. Using the very same approach we also improve previous designs of a small modal volume microcavity in silicon, gaining a factor of 3 in cavity Q. In view of practical realization of photonic crystals in synthetic diamond films, it is necessary to investigate the influence of material absorption on the quality factor. We show that this influence can be predicted by a simple model, replacing time consuming simulations.