A. Grunnetjepsen et al., SYSTEMATICS OF 2-WAVE MIXING IN A PHOTOREFRACTIVE POLYMER, Journal of the Optical Society of America. B, Optical physics, 15(2), 1998, pp. 905-913
The high-performance photorefractive polymer composite PVK:PDCST:BBP:C
-60 is investigated in detail by use of optical two-wave mixing charac
terization measurements in conjunction with the grating translation te
chnique for determination of the photorefractive phase shift. A large
effective trap density of N-eff = 1.5 x 10(17) cm(-3) is estimated fro
m the dependence of the phase shift on the grating spacing and the app
lied electric field. The theory of orientational enhancement is succes
sfully used to explain the observed photorefractive response, and in t
his low-glass-transition temperature system the modulation of the refr
active index is shown to stem primarily from the spatial modulation of
the birefringence. (C) 1998 Optical Society of America.