Ultrafast modulation in a THz graphene-based flat absorber through negative photoconductivity

TL;DR

This paper demonstrates an ultrafast graphene-based THz absorber modulator that uses negative photoconductivity to achieve rapid control of absorption, enabling advanced flat optics and metasurface applications.

Contribution

It introduces a novel graphene-based flat absorber modulator operating in the THz range with ultrafast modulation via negative photoconductivity, supported by experimental and theoretical analysis.

Findings

Ultrafast modulation achieved in THz regime.

Hot carrier generation reduces graphene conductivity.

Potential for flat optics and metasurface applications.

Abstract

We present the experimental and theoretical study of an ultrafast graphene based thin film absorption modulator for operation in the THz regime. The flat modulator is composed of a graphene sheet placed on a dielectric layer backed by a metallic back reflector. A near IR pulse induces the generation of hot carriers in the graphene sheet reducing effectively its conductivity. The system provides a platform with ultrafast modulation capability for flat optics and graphene based metasurfaces applications.