Scanning near-field optical microscopy of cholesteric liquid crystals

Abstract

We have studied glasslike cholesteric liquid crystals by means of scanning near-field optical microscopy. A periodic modulation of the optical polarization was used in order to achieve an optical contrast due to the birefringence of the liquid crystal. Variation of the cholesteric pitch indicates an optical resolution of ≈200 nm for a wavelength of 633 nm.