Broadband asymmetric transmission with tunable bilayer silicon nanoarrays: from visible to near-infrared

TL;DR

This paper presents a theoretical study of bilayer silicon nanoarrays that achieve broadband asymmetric light transmission with tunable parameters, suitable for optical isolation and sensing across visible to near-infrared wavelengths.

Contribution

It introduces a novel bilayer silicon array design enabling broadband asymmetric transmission with high isolation ratios, tunable by structural parameters.

Findings

Achieves broadband AT in specified wavelength ranges

Demonstrates high isolation ratios for different configurations

Shows potential for optical isolation and sensing applications

Abstract

A kind of asymmetric transmission (AT) device based on bilayer silicon arrays (BSA) nanostructure is theoretically explored, which achieves high forward transmissivity and suppressed backward transmissivity for broadband by simply adjusting the parameters of the structure. The structure consists of two silicon cylinder arrays, one on the SiO2 substrate and the other embedded in the substrate. Particularly, three AT devices with different configurations are designed, which exhibit broadband AT with high isolation ratios in the wavelength ranges of 685-807 nm, 866-1029 nm, and 1285-1536 nm, respectively. A comprehensive analysis of the BSA structure's performance across different array periods highlights its potential for broadband optical applications, such as optical isolation and multi-channel optical sensors.