Non-Hermitian heterostructure for two-parameter sensing

TL;DR

This paper proposes a multilayered non-Hermitian heterostructure with double exceptional points that can simultaneously sense two environmental parameters by analyzing changes in optical reflection due to temperature and stress fluctuations.

Contribution

It introduces a novel multilayered heterostructure design with double exceptional points enabling independent two-parameter sensing, advancing non-Hermitian optical sensor technology.

Findings

The heterostructure exhibits vanishing reflection coefficients at specific parameters.

Perturbations from temperature and stress alter the optical scattering properties.

The structure enables independent manipulation of responses for two parameters.

Abstract

Non-Hermitian systems at the exceptional point (EP) degeneracy are demonstrated to be highly sensitive to environmental perturbation. Here, we propose and theoretically investigate a novel multilayered heterostructure favoring double EPs for a unique set of material parameters at which forward- and backward-reflection coefficients vanish, respectively. Such an EP heterostructure is shown to scatter off light when system parameters are perturbed away from the degeneracies due to the effect of ambient temperature and mechanical stress fluctuations. The proposed structure is conducive in manipulating optical responses for two mutually independent parameters sensing.