Birefringence in silicon monoxide films used for aligning liquid crystal layers

Abstract

Obliquely evaporated thin films of silicon monoxide are widely used to align nematic liquid crystal layers in electro‐optic devices, but the mechanism of this alignment is incompletely understood. This letter reports that such films exhibit birefringence, despite the basically amorphous structure of SiO. The nature of the birefringence appears to be related to the manner in which the films align the nematic director. It is suggested that the phenomenon may be due to form birefringence caused by anisotropic morphology in the films.