Tailored synthesis of a nonlinear optical phosphate with a short absorption edge.

A nonlinear optical phosphate Ba5P6O20 was rationally developed by a tailored synthetic approach based on the use of flexible [P3O10](5-) units. The phosphate exhibits a very short absorption edge of λ=167 nm, which is among the shortest known in phase-matchable phosphates. First-principles electronic structure analysis elucidated the origin of the changes in the optical properties, and specifically in the absorption edge, of the material. Such a tailored synthetic approach provides a new opportunity to design nonlinear optical materials with short absorption edges.