Abstract

Anisotropic alignment of nonlinear chromophores and their dipolar stability are the key issues¹ of nonlinear optical (NLO) materials. Poling is a usual means in guest-host systems to bring about such an alignment²-⁴. Since poling is carried out around the glass transition temperature(T_g) of hosts⁵, and the temporal stability of chromophores depends primarily on T_g values of hosts, matrix materials for high-temperature stability are required to have high T_g such as with polyimides. However, the high-temperature poling causes problems in nonlinear chromophores, such as bleaching⁶-⁷, decomposition⁸,⁹ or loss of dipolar alignment¹⁰, unless they have very high decomposition temperatures. Also, a related problelm is a plasticizing effect⁸,¹¹ of chromophores which lowers the T_g of the matrix with increasing chromophore concentration.

© 1995 Optical Society of America