# Enhanced acousto-optic properties in layered media

## TL;DR

This paper introduces a rigorous method to evaluate and enhance acousto-optic properties in layered media, enabling tailored optical and acoustic interactions through structured composite materials.

## Contribution

It provides analytical expressions for photoelastic coefficients in layered media and demonstrates how to enhance and tune acousto-optic responses beyond individual materials.

## Key findings

- Enhanced acousto-optic coefficients in layered structures
- Artificial contributions from material contrast influence properties
- Tunable acousto-optic response in composite media

## Abstract

We present a rigorous procedure for evaluating the photoelastic coefficients of a layered medium where the periodicity is smaller than the wavelengths of all optical and acoustic fields. Analytical expressions are given for the coefficients of a composite material comprising thin layers of optically isotropic materials. These coefficients include artificial contributions that are unique to structured media and arise from the optical and mechanical contrast between the constituents. Using numerical examples, we demonstrate that the acousto-optic properties of layered structures can be enhanced beyond those of the constituent materials. Furthermore, we show that the acousto-optic response can be tuned as desired.