Directional silicon nano-antennas for quantum emitter control designed by evolutionary optimization

TL;DR

This paper presents the design of silicon nano-antennas optimized via evolutionary algorithms to control and enhance directional emission of quantum sources, with robustness and potential for nanophotonics and quantum tech applications.

Contribution

It introduces a combined optimization and simulation approach for designing silicon nano-antennas with controllable emission properties, comparing resonant and non-resonant designs.

Findings

Simpler geometric models enable faster optimization convergence.

Directional emission with emission rate enhancement is achieved.

Designs show robustness against emitter position perturbations.

Abstract

We optimize silicon nano-antennas to enhance and steer the emission of local quantum sources. We combine global evolutionary optimization (EO) with frequency domain electrodynamical simulations, and compare design strategies based on resonant and non-resonant building blocks. Specifically, we investigate the performance of models with different degrees of freedom but comparable amount of available material. We find that simpler geometric models allow significantly faster convergence of the optimizer, which, expectedly, comes at the cost of a reduced optical performance. We finally analyze the physical mechanisms underlying the directional emission that also comes with an emission rate enhancement, and find a surprising robustness against perturbations of the source emitter location. This makes the structures highly interesting for actual nano-fabrication. We believe that optimized, all-dielectric silicon nano-antennas have high potential for genuine breakthroughs in a multitude of applications in nanophotonics and quantum technologies.