Eur. Phys. J. Plus (2021) 136: 296
https://doi.org/10.1140/epjp/s13360-021-01259-5

Regular Article

The effect of laser wavelength and concentration on the optical limiting response of exfoliated MoS₂ in the NMP solvent

¹ Department of Physics, Shahid Beheshti University, 1983969411, Tehran, Iran
² Department of Electrical Engineering, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran

^b r_karimzadeh@sbu.ac.ir

Received: 22 May 2020
Accepted: 21 February 2021
Published online: 6 March 2021

Abstract

This study investigated the optical limiting (OL) response of the dispersion of MoS₂ nanosheets in N-methyl-2-pyrrolidone (NMP) which was made by liquid-phase exfoliation. We measured the OL response of different concentrations of the samples at two wavelengths of 405 nm and 532 nm using a continuous wave (CW) laser irradiation. It was observed that the value of the OL threshold changes by changing the laser wavelength and MoS₂ concentration. To understand the mechanisms underlying these results, we use the spatial self-phase modulation (SSPM) and the Z-scan methods to measure the nonlinear absorption and refraction coefficients. It was revealed that the nonlinear absorption response is too weak. These findings highlight the significant role of the nonlinear refraction effect in the spatial self-phase modulation and the OL response of MoS₂ dispersion under low-power laser irradiation.