Selective reflection in the cholesteric and blue phases of a chiral-racemic mixture of CE6

The reflection spectrum for visible light is examined for the cholesteric and blue phases of chiral CE6. Pronounced side band oscillations are observed. The Bragg wavelength for total reflection diverges towards the smectic phase with an exponent v = 0·71±0·05. Going from the cholesteric phase to BPI, the lattice parameter increases by (2)1/2. Evidence is given for the existence of a long-lived supercooled blue phase (BPS).