Dielectric behavior of two epoxy-based oligomers with covalently attached 4-amino-4'-nitroazobenzene NLO chromophore fragments is studied. Four processes of relaxation of dipole polarization, gamma-, beta-, beta(1)-, and alpha-processes are identified by the method of dielectric spectroscopy. Monte-Carlo conformational analysis and molecular dynamics of dimeric chain fragments of these polymers is performed and mobilities of specific chain fragments are estimated. Molecular mechanisms for the gamma-, beta-, and beta(1)- processes, occurring in the glassy state, are suggested on the basis of a comparison of the dielectric spectroscopy and molecular modeling data. (C) 2012 Elsevier B.V. All rights reserved.