Abstract

Organic salts based on strong Coulomb interactions between charged molecules often show non-centrosymmetric packing as e.g. the 4-dimethylamino-N-methyl-stilbazolium salts. The material with the largest second-order nonlinearities in this class is 4-N,N-dimethylamino-4′-N′-methyl-stilbazolium tosylate (DAST). DAST crystals are very interesting especially for electro-optic applications due to the exceptionally large nonlinear optical susceptibilities, the good alignment of the chromophores in the crystal and the large crystal size [1]. Due to the almost parallel alignment of the stilbazolium chromophores DAST was believed to be less suitable for phase-matched parametric interactions such as e.g. frequency-doubling.

© 1998 IEEE