Coherent control of light interaction with graphene

TL;DR

This paper demonstrates all-optical modulation of light using a graphene film by exploiting coherent absorption in a standing wave, achieving high efficiency and controllable scattering, enabling advanced optical switching at sub-wavelength scales.

Contribution

The study presents the first experimental demonstration of coherent control of light interaction with graphene using standing wave interference.

Findings

Achieved nearly 80% modulation efficiency of transmission.

Controlled scattering by positioning graphene at nodes and antinodes.

Showed potential for sub-wavelength optical switching.

Abstract

We report the experimental observation of all-optical modulation of light in a graphene film. The graphene film is scanned across a standing wave formed by two counter-propagating laser beams in a Sagnac interferometer. Through a coherent absorption process the on-axis transmission is modulated with close to 80% efficiency. Furthermore we observe modulation of the scattered energy by mapping the off-axis scattered optical signal: scattering is minimized at a node of the standing wave pattern and maximized at an antinode. The results highlight the possibility to switch and modulate any given optical interaction with deeply sub-wavelength films.