Enhancing optical anisotropy of crystals by optimizing bonding electron distribution in anionic groups.

The response electron distribution anisotropy (REDA) approximation was proposed to analyze the relationship between optical anisotropy and distribution of bonding electrons in compounds. Further, the optical anisotropy of tetrahedral chromophore compounds with common small birefringence can be enhanced and excellent nonlinear optical properties can be obtained by optimizing the distribution.