AlGaN/AlN heterostructures: an emerging platform for nonlinear integrated photonics

TL;DR

This paper introduces AlGaN/AlN heterostructures as a new integrated photonics platform combining nonlinear optical capabilities, compatibility with existing fabrication processes, and broad spectral transmission for advanced quantum and classical photonic applications.

Contribution

The work presents the design, growth, and integration of AlGaN/AlN heterostructures with fundamental photonic components, enabling nonlinear and quantum functionalities on-chip.

Findings

Successful fabrication of low-loss waveguides and high-Q resonators

Demonstration of nonlinear light-matter interactions

Potential for quantum frequency conversion and fast modulation

Abstract

In the rapidly evolving area of integrated photonics, there is a growing need for materials that satisfy the particular requirements of increasingly complex and specialized devices and applications. Present photonic material platforms have made significant progress over the past years; however, each platform still faces specific material and performance challenges. We introduce a novel material for integrated photonics: Aluminum Gallium Nitride (AlGaN) on Aluminum Nitride (AlN) as a platform for developing reconfigurable and nonlinear on-chip optical systems. AlGaN combines compatibility with standard semiconductor fabrication technologies, high electro-optic modulation capabilities, and large nonlinear coefficients while providing a broad and low-loss spectral transmission range, making it a viable material for advanced photonic applications. In this work, we design and grow AlGaN/AlN heterostructures and integrate fundamental photonic building blocks into these chips. In particular, we fabricate edge couplers, low-loss waveguides, directional couplers, and tunable high-quality factor ring resonators to enable nonlinear light-matter interaction and quantum functionality. The comprehensive platform we present in this work paves the way for nonlinear photon-pair generation applications, on-chip nonlinear quantum frequency conversion, and fast electro-optic modulation for switching and routing classical and quantum light fields.