(2) Diffusion type polarizer.
A film, in which microcrystals are uniaxially aligned works as diffusion
type polarizer, if one of the refractive indices of microcrystal coincides
with the matrix transparent polymer. Combination of urea crystal and PEMA
satisfies the above condition. Magnetic alignment is used to align urea
microcrystals. [Polymer Prep. Jpn, 51, 726 (2002)]