Nonlinear optical response spatial self-hase modulation in MoTe2: correlations between \c{hi}(3) and mobility or effective mass

TL;DR

This study demonstrates third-order nonlinear optical effects in MoTe2, revealing how b3(3) correlates with carrier mobility and effective mass, advancing understanding of laser-induced coherence in 2D materials.

Contribution

It provides the first clear observation of SSPM in MoTe2 and links nonlinear optical coefficients with electronic properties like mobility and effective mass.

Findings

b3(3) varies with wavelength and correlates with photo-absorption spectra.

A correlation exists between b3(3) and carrier mobility or effective mass.

Ring formation time explained by the wind-chime model.

Abstract

We report an unambiguous observation of third-order nonlinear optical effect, spatial self-phase modulation (SSPM), in a MoTe2 dispersion. The values of the third order nonlinear optical coefficients effectively for one layer MoTe2, \c{hi}(3)one-layer, are obtained through the SSPM method at excitation wavelengths 473, 532, 750 and 801 nm, respectively. The wind-chime model is used to explain the ring formation time. The wavelength dependence of \c{hi}(3)one-layer compares well with the photo-absorption spectra. Significantly, we find a correlation between \c{hi}(3) and the carrier mobility {\mu} or effective mass m*, which again further supports the laser-induced ac electron coherence in 2D materials.