Nonlinear optics of nonabsorbing chiral media: experiments on frustration of selective reflection by powerful laser radiation

Summary form only given. The problems of light-induced pitch dilation of the cholesteric liquid crystal (CLC) helix under the conditions of selective Bragg reflection of circular polarized light with changing of reflectivity of the CLC have been widely discussed theoretically. We observed two nonlinear effects under the irradiation of nonabsorbing CLC mirrors by circular polarized laser light: (1) strong lowering of reflectivity (firstly in our knowledge) with possibility to return to the initial state for not very strong bleaching; (2) changes of the CLC mirror curvature under the irradiation by the Gaussian beam.