Optical Limiting and Theoretical Modelling of Layered Transition Metal Dichalcogenide Nanosheets

TL;DR

This study investigates the nonlinear optical properties of layered transition metal dichalcogenide nanosheets using Z-scan measurements, revealing their potential for optical limiting applications and proposing a theoretical model for their behavior.

Contribution

It introduces a liquid dispersion system based theoretical model to estimate nanosheet density and laser-induced micro-bubble effects in TMDC dispersions.

Findings

TMDC dispersions show significant optical limiting at 1064 nm due to nonlinear scattering.

Selenium compounds outperform sulfides in near-infrared optical limiting.

Theoretical model links laser fluence, micro-bubble size, and scattering behavior.

Abstract

Nonlinear optical property of transition metal dichalcogenide (TMDC) nanosheet dispersions, including MoS2, MoSe2, WS2, and WSe2, was performed by using Z-scan technique with ns pulsed laser at 1064 nm and 532 nm. The results demonstrate that the TMDC dispersions exhibit significant optical limiting response at 1064 nm due to nonlinear scattering, in contrast to the combined effect of both saturable absorption and nonlinear scattering at 532 nm. Selenium compounds show better optical limiting performance than that of the sulfides in the near infrared. A liquid dispersion system based theoretical modelling is proposed to estimate the number density of the nanosheet dispersions, the relationship between incident laser fluence and the size of the laser generated micro-bubbles, and hence the Mie scattering-induced broadband optical limiting behavior in the TMDC dispersions.