Inverse angle dependence of the reflection colours of cholesteric polymeric liquid crystals mixed with pigments

Measurements on thin layers of cholesteric liquid crystals with a cyclic polysiloxane backbone show the usual angle dependence of the reflection wavelength, namely a shift to shorter wavelengths with increasing angle of observation. By mixing these liquid-crystalline side chain polymers with suitable pigments or dyes or by choice of a suitable coloured background, a red shift of the reflection colour with increasing angle can be obtained.