Response of graphene to femtosecond high-intensity laser irradiation

TL;DR

This study investigates how graphene responds to high-intensity femtosecond laser pulses, identifying damage thresholds, defect formation, and the limits for nonlinear optical applications.

Contribution

It provides the first detailed analysis of graphene's damage threshold and defect dynamics under femtosecond laser irradiation using in-situ Raman microscopy.

Findings

Graphene's single-shot damage threshold is approximately 3×10^12 W/cm^2.

Laser-induced defects degrade the lattice over multiple exposures below the damage threshold.

The effective lifetime of CVD graphene under femtosecond irradiation depends on laser intensity.

Abstract

We study the response of graphene to high-intensity 10^11-10^12 Wcm^-2, 50-femtosecond laser pulse excitation. We establish that graphene has a fairly high (~3\times10^12Wcm^-2) single-shot damage threshold. Above this threshold, a single laser pulse cleanly ablates graphene, leaving microscopically defined edges. Below this threshold, we observe laser-induced defect formation that leads to degradation of the lattice over multiple exposures. We identify the lattice modification processes through in-situ Raman microscopy. The effective lifetime of CVD graphene under femtosecond near-IR irradiation and its dependence on laser intensity is determined. These results also define the limits of non-linear applications of graphene in femtosecond high-intensity regime.