# Realization of an atomically thin mirror using monolayer MoSe2

## TL;DR

This paper demonstrates an electrically tunable, atomically-thin mirror using monolayer MoSe2 that achieves high extinction and reflection, with potential applications in optical modulation and optomechanics.

## Contribution

The study experimentally realizes a monolayer MoSe2-based mirror with electrical tunability and high reflectivity, advancing 2D material applications in photonics.

## Key findings

- Achieves 90% extinction of resonant incident light.
- Maximum reflection coefficient of 45%.
- Reflectivity is tunable via gate voltage.

## Abstract

Advent of new materials such as van der Waals heterostructures, propels new research directions in condensed matter physics and enables development of novel devices with unique functionalities. Here, we show experimentally that a monolayer of MoSe2 embedded in a charge controlled heterostructure can be used to realize an electrically tunable atomically-thin mirror, that effects 90% extinction of an incident field that is resonant with its exciton transition. The corresponding maximum reflection coefficient of 45% is only limited by the ratio of the radiative decay rate to the linewidth of exciton transition and is independent of incident light intensity up to 400 Watts/cm2. We demonstrate that the reflectivity of the mirror can be drastically modified by applying a gate voltage that modifies the monolayer charge density. Our findings could find applications ranging from fast programmable spatial light modulators to suspended ultra-light mirrors for optomechanical devices.