Graphene Mode-Locked Ultrafast Laser

TL;DR

This paper demonstrates the use of graphene's optoelectronic properties to create a passively mode-locked ultrafast laser with sub-picosecond pulses, highlighting graphene's potential in photonics applications.

Contribution

The authors fabricated a graphene-polymer composite and utilized its saturable absorption for passive mode-locking of an Erbium-doped fiber laser at 1559nm.

Findings

Achieved ~460fs pulse duration

Demonstrated wavelength-independent saturable absorption

Paved the way for graphene-based photonics

Abstract

Graphene is at the center of a significant research effort. Near-ballistic transport at room temperature and high mobility make it a potential material for nanoelectronics. Its electronic and mechanical properties are also ideal for micro and nanomechanical systems, thin-film transistors and transparent and conductive composites and electrodes. Here we exploit the optoelectronic properties of graphene to realize an ultrafast laser. A graphene-polymer composite is fabricated using wet-chemistry techniques. Pauli blocking following intense illumination results in saturable absorption, independent of wavelength. This is used to passively mode-lock an Erbium-doped fibre laser working at 1559nm, with a 5.24nm spectral bandwidth and ~460fs pulse duration, paving the way to graphene-based photonics.