Influence of cholesteric Bragg reflection on spontaneous emission from the inside of the helical structure

Abstract Spontaneous emission from a luminescent center doped in the periodic structure of a cholesteric liquid crystal is experimentally investigated. The characteristic Bragg reflection for the light emitted from the inside of the helical structure is observed as a deep dip in the emission spectrum, when the emission band is wider than the reflection band. The dip position identical to the optical pitch shifts as a function of temperature. The luminescence intensity decay profiles, however, show no meaningful difference over two decades between the cases that the Bragg condition is satisfied or not, contrary to the experimental observation by Dreher and Schomburg.