Characterization of nonlinear crystals for high-energy lasers

Frequency conversion of optical pulses produced by solid-state lasers and parametric amplification of broadband optical pulses are made possible at high energy by the manufacturing of high-quality, large-aperture nonlinear crystals. Phase matching of the interacting waves is required for efficient interactions, and in the common case of critical phase matching, this requires precise control of the interaction geometry and crystal alignment. A diagnostic suitable for accurately resolving the transverse variations in phase-matching conditions has been developed for large-scale crystals. Results pertaining to deuterated dihydrogen phosphate (DKDP) and other crystals will be presented.