T Grating on Nano-Cavity Array based Refractive Index Sensor

TL;DR

This paper introduces a novel T grating nano-cavity array sensor capable of simultaneous multi-analyte detection with high sensitivity and self-referencing, suitable for biochemical sensing across a broad refractive index range.

Contribution

The work presents a unique T grating on nano-cavities enabling dual-mode sensing with minimal interference and broad-range self-referencing, advancing nano-photonic sensor design.

Findings

Sensitivity of 801.7 nm/RIU for one mode

Sensitivity of 1386.8 nm/RIU for the other mode

Effective detection across refractive indices 1.3 to 1.5

Abstract

We report a refractive index sensor comprising of unique T grating on top of periodic nano-cavities. The sensor has two resonant modes sensitive to different regions of the structure with low inter-region interference, hence allows simultaneous detection of two different analytes or more accurate detection of a single analyte. The sensor also provides a self-referencing feature for a broad range of refractive index, from 1.3 to 1.5. Using the FDTD method, the sensitivities of 801.7 nm/RIU and 1386.8 nm/RIU have been recorded for the two modes respectively. The versatility of the structure makes the sensor a prominent candidate for biochemical and other sensing applications.