Photorefractivity and transmission-type holograms of a poly(N-vinylcarbazole)-based composite with N-4-nitrophenyl-(l)-prolinol as chromophore

The photorefractivity of a poly(N-vinylcarbazole)/2,4,7-trinitro-9-fluoren- one/N-4-nitrophenyl-(l)-prolinol/N-ethylcarbazole composite was investigate d by two-beam coupling and degenerate four-wave mixing experiments. The com posite in a weight ratio 35 : 1 : 50 : 15 exhibited a 22% steady-state diff raction efficiency and 70 cm(-1) two-beam coupling coefficient at the appli ed external field of 55 V/mu m. Zero applied field transmission-type hologr ams were observed in the photorefractive sample as well as the spin-coated thin film. The dynamic decay of diffraction light indicated that there exis ted two contributors with different phase-shift, and the slow decay time ca n be as long as several h under continuous illumination by the readout beam . (C) 2000 John Wiley & Sons, Inc.