CdSiP₂: An Emerging Crystal for Electro-Optic Sampling from Terahertz to the Infrared

Abstract

An emerging crystal, CdSiP 2 , is shown to exhibit a higher nonlinearity than other key electro-optic sampling crystals, while also satisfying the electro-optic sampling phasematching conditions across the spectral range of ∼15−90 THz. Frequencies up to ∼65 THz are measured using an 800 nm central-wavelength probe electric field pulse and a (110) CdSiP 2 crystal; however, a higher central-wavelength (i.e., 1.3 μm) probe pulse can be used to record frequencies up to 90 THz. Given the high nonlinearity and electro-optic phasematching capabilities of CdSiP 2 , it is envisioned to emerge as the prominent crystal for detecting electric field waveforms within the high terahertz and infrared spectral regimes.