The reflection spectrum of light from the surface of a cholesteric liquid crystal film has been theoretically studied by including the absorption of light by the material. The intensity of reflection is found as a function of the wavelength and the angle of incidence as well as the angle of reflection near the circular dichroism region. A good agreement has been obtained with the available experimental data.
S. V. Subramanyam, "Optical Reflection from Cholesteric Liquid Crystal Films," Appl. Opt. 10, 317-320 (1971)