Enhanced Light-Matter Interactions in Dielectric Nanostructures via Machine Learning Approach

TL;DR

This paper introduces a deep learning method to design dielectric metasurfaces with high-Q resonances, significantly enhancing light-matter interactions such as third harmonic generation and optomechanical vibrations.

Contribution

It presents a novel deep-learning-based optimization approach for designing metasurfaces with tailored high-Q resonances, improving efficiency over traditional multi-parameter optimization methods.

Findings

Achieved over 400-fold enhancement in third harmonic generation.

Realized more than 100-fold enhancement in optomechanical vibrations.

Demonstrated the potential for designing structures with unconventional scattering responses.

Abstract

A key concept underlying the specific functionalities of metasurfaces, i.e. arrays of subwavelength nanoparticles, is the use of constituent components to shape the wavefront of the light, on-demand. Metasurfaces are versatile and novel platforms to manipulate the scattering, colour, phase or the intensity of the light. Currently, one of the typical approaches for designing a metasurface is to optimize one or two variables, among a vast number of fixed parameters, such as various materials' properties and coupling effects, as well as the geometrical parameters. Ideally, it would require a multi-dimensional space optimization through direct numerical simulations. Recently, an alternative approach became quite popular allowing to reduce the computational cost significantly based on a deep-learning-assisted method. In this paper, we utilize a deep-learning approach for obtaining high-quality factor (high-Q) resonances with desired characteristics, such as linewidth, amplitude and spectral position. We exploit such high-Q resonances for the enhanced light-matter interaction in nonlinear optical metasurfaces and optomechanical vibrations, simultaneously. We demonstrate that optimized metasurfaces lead up to 400+ folds enhancement of the third harmonic generation (THG); at the same time, they also contribute to 100+ folds enhancement in optomechanical vibrations. This approach can be further used to realize structures with unconventional scattering responses.