Interpretable inverse-designed cavity for on-chip nonlinear and quantum optics

TL;DR

This paper introduces an interpretable inverse design approach for nonlinear photonic devices, demonstrated by a silicon-on-insulator cavity that efficiently generates photon pairs for quantum optics applications.

Contribution

It presents a novel inverse design method that produces interpretable structures for nonlinear photonics, enabling scalable quantum light sources with controlled phase-matching.

Findings

Photon pairs generated at 1.1 MHz

Coincidence to accidental ratio of 162

Design accounts for fabrication constraints

Abstract

Inverse design is a powerful tool in wave-physics and in particular in photonics for compact, high-performance devices. To date, applications have mostly been limited to linear systems and it has rarely been investigated or demonstrated in the nonlinear regime. In addition, the "black box" nature of inverse design techniques has hindered the understanding of optimized inverse-designed structures. We propose an inverse design method with interpretable results to enhance the efficiency of on-chip photon generation rate through nonlinear processes by controlling the effective phase-matching conditions. We fabricate and characterize a compact, inverse-designed device using a silicon-on-insulator platform that allows a spontaneous four-wave mixing process to generate photon pairs at 1.1MHz with a coincidence to accidental ratio of 162. Our design method accounts for fabrication constraints and can be used for scalable quantum light sources in large-scale communication and computing applications.