Observation of Electro-Optical Effects in Blue Phase Systems

The blue phases of two cholesteric systems are studied under the influence of an electric field. The wavelength of maximum absorption due to the selective reflection of circularly polarized light of both blue phase I (BP I) and blue phase II (BP II) turns out to be shifted to longer wavelengths with increasing electric field. In addition to that, a phase transition from BP II to BP I is observed for one of the systems used. Under favorable conditions, brilliant color changes from blue to red are observed in the reflected light.