HOLOGRAM RECORDING IN DUPONT PHOTOPOLYMER FILMS BY USE OF PULSE EXPOSURE

Reflection hologram recording in DuPont HRF-800X071-20 photopolymer fi lms has been demonstrated by use of pulsed laser exposure with pulse l engths of 25 ns. An expected weak reflectance of the recorded mirror h olograms could be significantly increased by preillumination. Although pulsed preillumination enhanced only the reflectance, continuous inco herent preillumination significantly increased both the diffraction ef ficiency (which reached similar to 80%) and the sensitivity (which rea ched an increase of similar to 100 times, thus approaching the sensiti vity of cw recording). The results are compared with those for hologra m recordings obtained with cw exposure under the same processing condi tions. Spectral absorbance curves of recorded holograms are presented, and possible mechanisms of hologram formation are discussed. (C) 1997 Optical Society of America.