Electrooptics of graphene: field-modulated reflection and birefringence

TL;DR

This paper theoretically investigates how heating and electric drift affect graphene's electrooptical properties, including reflection, absorption, and birefringence, under various spectral and field conditions.

Contribution

It provides a theoretical analysis of graphene's dynamic conductivity tensor and optical responses considering anisotropy and carrier distribution controlled by external fields.

Findings

Reflection coefficient varies with spectral and electric field parameters.

Graphene exhibits small birefringence leading to ellipticity in reflected and transmitted light.

The study offers insights into field-dependent optical modulation of graphene.

Abstract

The elecrooptical response of graphene due to heating and drift of carriers is studied theoretically. Real and imaginary parts of the dynamic conductivity tensor are calculated for the case of effective momentum relaxation, when anisotropic contributions are small. We use the quasiequilibrium distribution of electrons and holes, characterized by the effective temperature of carriers and by concentrations, which are controlled by gate voltage and in-plane electric field. The geometry of normal propagation of probe radiation is considered, spectral and field dependences of the reflection coefficient and the relative absorption are analyzed. The ellipticity degree of the reflected and transmitted radiation due to small birefringence of graphene sheet with current have also been determined.