Gain Modulation by Graphene Plasmons in Aperiodic Lattice Lasers

TL;DR

This paper demonstrates how graphene plasmons can be used to actively tune terahertz lasers by controlling doping levels, enabling programmable plasmonic devices with broad applications.

Contribution

It introduces a novel method of modulating laser emission using graphene plasmons within an aperiodic lattice laser, linking doping to photon lifetime control.

Findings

Graphene plasmons enable reversible tuning of laser emission.

Laser spectra are highly sensitive to graphene doping levels.

The approach paves the way for programmable plasmonic metamaterials.

Abstract

Two-dimensional graphene plasmon-based technologies will enable the development of fast, compact and inexpensive active photonic elements because, unlike plasmons in other materials, graphene plasmons can be tuned via the doping level. Such tuning is harnessed within terahertz quantum cascade lasers to reversibly alter their emission. This is achieved in two key steps: First by exciting graphene plasmons within an aperiodic lattice laser and, second, by engineering photon lifetimes, linking graphene's Fermi energy with the round-trip gain. Modal gain and hence laser spectra are highly sensitive to the doping of an integrated, electrically controllable, graphene layer. Demonstration of the integrated graphene plasmon laser principle lays the foundation for a new generation of active, programmable plasmonic metamaterials with major implications across photonics, material sciences and nanotechnology.