Birefringence Modulated Scattering in Gels

(Received 5 December 1994, accepted in final form 5 January 1995)

Abstract
We describe a novel effect that arises when a monochromatic light beam passes through a deswollen rigid-rod gel. When viewed perpendicular to the direction of propagation, under suitable conditions of polarisation, a pattern of fringes is observed. The phenomenon is a simple geometrical optical effect caused by the birefringence of the sample. For a given wavelength of incident light, observation of the spatial frequency of the fringes, , offers an inexpensive means of measuring the magnitude of the birefringence . With white incident light, the fringes transform into an iridescent pattern.