Multi-objective Inverse Design of Solid-state Quantum Emitter Single-photon Sources

TL;DR

This paper introduces a multi-objective inverse design method for solid-state quantum emitters, optimizing key figures-of-merit like Purcell enhancement and coupling efficiency to improve single-photon source performance.

Contribution

The paper presents a novel inverse design approach that simultaneously optimizes multiple performance metrics for quantum light sources, explicitly considering geometry-dependent emission.

Findings

Achieved Purcell factor of 21 with 94% waveguide coupling efficiency

Design respects geometric constraints to minimize decoherence

Multi-objective inverse design outperforms conventional geometries

Abstract

Single solid-state quantum emitters offer considerable potential for the implementation of sources of indistinguishable single-photons, which are central to many photonic quantum information systems. Nanophotonic geometry optimization with multiple performance metrics is imperative to convert a bare quantum emitter into a single-photon source that approaches the necessary levels of purity, indistinguishability, and brightness for quantum photonics. We present an inverse design methodology that simultaneously targets two important figures-of-merit for high-performance quantum light sources: the Purcell radiative rate enhancement and the coupling efficiency into a desired light collection channel. We explicitly address geometry-dependent power emission, a critical but often overlooked aspect of gradient-based optimization of quantum emitter single-photon sources. We illustrate the efficacy of our method through the design of a single-photon source based on a quantum emitter in a GaAs nanophotonic structure that provides a Purcell factor $F_p=21$ with a 94% waveguide coupling efficiency, while respecting a geometric constraint to minimize emitter decoherence by etched sidewalls. Our results indicate that multi-objective inverse design can yield competitive performance with more favorable trade-offs than conventional approaches based on pre-established waveguide or cavity geometries.