Hendrickx, E; Guenther, BD; Zhang, Y; Wang, JF; Staub, K; Zhang, Q; Marder, SR; Kippelen, B; Peyghambarian, N, *Ellipsometric determination of the electric-field-induced birefringence of photorefractive dyes in a liquid carbazole derivative*,
Chem. Phys. (Netherlands), vol. 245 no. 1-3
(1999),
pp. 407-415 [S0301-0104(99)00049-X], [doi] .
**Abstract:**

*We have used ellipsometric measurements on solutions of 2-dihexylamino-7-dicyanomethylidene-3,4,4a,5,6-pentahydronaphthalene and related polyenes in liquid 9-(2'-ethylhexyl)carbazole to measure the electric-field-induced birefringence at wavelengths of 690 nm and 830 nm. This electric-field-induced birefringence is related to the product of dipole moment squared and the polarizability anisotropy, μ2Δα, and to a large extent determines the dye's photorefractive figure-of-merit (FOM). We show that μ2Δα increases with the conjugation length and report one of the highest μ2Δα values observed so far*