Optical Kerr nonlinearity and multi-photon absorption of DSTMS measured by Z-scan method

TL;DR

This study measures the optical Kerr nonlinearity and multi-photon absorption of DSTMS at 1.43 μm using Z-scan, revealing anisotropic nonlinear properties that impact terahertz generation efficiency.

Contribution

First measurement of DSTMS's nonlinear optical properties at 1.43 μm, highlighting anisotropy and cascaded second-order effects relevant for terahertz applications.

Findings

MPA and Kerr coefficients are strongly anisotropic.

Cascaded second-order nonlinearity dominates the nonlinear response.

THz generation saturation is linked to MPA and spectral broadening.

Abstract

We investigate the optical Kerr nonlinearity and multi-photon absorption (MPA) properties of DSTMS excited by femtosecond pulses at a wavelengths of 1.43 {\mu}m, which is optimal for terahertz generation via difference frequency mixing. The MPA and the optical Kerr coefficients of DSTMS at 1.43 {\mu}m are strongly anisotropic indicating a dominating contribution from cascaded 2nd-order nonlinearity. These results suggest that the saturation of the THz generation efficiency is mainly related to the MPA process and to a spectral broadening caused by cascaded 2nd-order frequency mixing within DSTMS