Structure of reflections bands of Grandjean textures

The characteristic exponents of the normal modes for light in the Grandjean texture of a cholesteric film were calculated with values for the dielectric constants that are typical for common cholesteryl derivatives. The reflection properties are discussed in terms of the penetration depth given by the real part of the characteristic exponent. The results are presented in graphs which give the structure and the reflection coefficients as a function of wavelength and angle of incidence. It was found that there are unpolarized bands that are missing in a stability chart published earlier.