# High-sensitivity plasmonic refractive index sensing using graphene

## TL;DR

This paper presents a theoretical study of a graphene-based plasmonic sensor that achieves high sensitivity for detecting refractive index changes in the mid-infrared at room temperature, emphasizing surface sensitivity and realistic material parameters.

## Contribution

It introduces a novel graphene-plasmon sensor design with high surface sensitivity and realistic modeling of doping and relaxation effects, advancing mid-infrared sensing technology.

## Key findings

- Bulk figure of merit exceeds 10
- High surface sensitivity demonstrated
- Sensor performance limited by electron relaxation time

## Abstract

We theoretically demonstrate a high-sensitivity, graphene-plasmon based refractive index sensor working in the mid-infrared at room temperature. The bulk figure of merit of our sensor reaches values above $10$, but the key aspect of our proposed plasmonic sensor is its surface sensitivity which we examine in detail. We have used realistic values regarding doping level and electron relaxation time, which is the limiting factor for the sensor performance. Our results show quantitatively the high performance of graphene-plasmon based refractive index sensors working in the mid-infrared.