Graphene Mode-Locked Ultrafast Laser

TLDR

Graphene’s exceptional electronic, mechanical, and optical properties—such as near‑ballistic transport, high mobility, and suitability for nanoelectronics, micro‑mechanical systems, thin‑film transistors, and transparent conductive composites—make it a focus of intense research. The study aims to use graphene’s optoelectronic properties to create an ultrafast laser. A graphene‑polymer composite is fabricated by wet‑chemistry, and its saturable absorption—arising from Pauli blocking under intense illumination and independent of wavelength—is employed. This enables passive mode‑locking of an Erbium‑doped fibre laser at 1559 nm, producing a 5.24 nm bandwidth and ~460 fs pulses, paving the way to 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.