Highly Sensitive and Robust Ultrahigh-Q Nanocavity on a Multiheterostructure Photonic Crystal

TL;DR

This paper presents a design for a highly sensitive and robust ultrahigh-Q nanocavity in a multiheterostructure photonic crystal, capable of precise sensing and resilient to fabrication errors.

Contribution

It introduces a novel hybrid cavity design with a new analytical method and demonstrates enhanced robustness and sensitivity for refractive index sensing.

Findings

Cavity supports two high-Q resonant modes with separate confinement mechanisms.

Modes are highly robust against fabrication errors.

Nanocavity functions effectively as a sensitive refractive index sensor.

Abstract

An ultrahigh-Q hybrid cavity using a graded multiheterostructure and space modulation is designed in this work. Two high Q resonant modes exist in the cavity and follow separate confinement mechanisms. We have demonstrated an analytical method for designing the desired multiheterostructure. Space modulation was used to create a robust and sensitive nanocavity. The confinement mechanism and resonant characteristics of the resonant modes are studied using the finite difference time domain method. We have shown that the modes of the cavity are highly robust with respect to fabrication error. We have also demonstrated that the nanocavity can act as a highly sensitive refractive index sensor.