Geometrical Optics Analysis of Diffraction in Patterned Cholesteric Liquid Crystals

A geometrical optics method is developed to analyze the diffraction in patterned cholesteric liquid crystals. We extend the equation for the center wavelength of selective reflection in a conventional cholesteric liquid crystal to the wavelength edges of the diffraction in patterned cholesteric liquid crystals. This method can be used to determine the reflection bandwidth and its wavelength edges of patterned cholesteric liquid crystals which depends on a slant angle and an incident angle. Furthermore, we also investigate a difference in the diffraction between planar and slanted patterned cholesteric liquid crystals using the geometrical optics method.