Crystal Growth, Tetrahertz Generation, and Optical Characterization of EHPSI-4NBS

Abstract

Nonlinear optical (NLO) organic crystals such as DAST, OH1, HMQ-TMS, and BNA have shown value as highly efficient terahertz (THz) generators, compared to their inorganic crystal counterparts. This is due to their higher peak electric fields and THz pulses with broader bandwidths generated with simple optical rectification setups. However, organic crystals exhibit phonon absorptions that reduce the THz output at specific frequencies. This is clearly appreciated in the state-of-the-art DAST crystal, which shows a significant generation dip at 1.1 THz. To solve this problem, new NLO organic crystals capable of producing THz radiation with unique spectra are under constant development, and the discovery of improved THz sources can help accelerate a host of condensed matter studies that are enabled with high-field THz science. In this article, we introduce the crystal growth and optical characterization of EHPSI-4NBS, and a comprehensive comparison of THz generation with benchmark organic crystals, showing that this novel crystal features higher generated electric fields. EHPSI-4NBS covers the electromagnetic spectrum from 0.1 to 3.8 THz without significant generation dips. These advantages make EHPSI-4NBS a promising crystalline material for THz generation applications.