Characterization Of Partially Deuterated Kdp Crystals Using Two-Wavelength Phase-Matching

Partially deuterated potassium dihydrogen phosphate (DKDP) allows for the optical parametric chirped-pulse amplification of high-energy broadband optical pulses to generate ultrashort, high-peak-power pulses. Modeling and experimental optimization of the noncollinear interaction geometry require the combination of a model for the deuteration-dependent optical indices and knowledge of the deuteration level of the DKDP crystal being used. We study and demonstrate a novel experimental technique that determines the deuteration level of a DKDP crystal consistent with a specific index model, based on the phase-matching angles measured at two wavelengths. Simulations and experiments show that the simple two-wavelength technique allows for consistent results with three different index models, and in particular, for the characterization of four crystals with deuteration levels ranging from 70% to 98%.(c) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement