Photochromic Property And Its Holographic Application Of BR-D96N Film

Bacteriorhodopsin (BR) is a kind of light-sensitive protein found in hfobacterium salinarium. BR is a macromolecular biomaterial with excellent optical qualities. In which, its photochromic character can be used in holographic storage. Compared with other kinds of optical storage technology, holographic storage has advantages like high storage density and high speed of reading and writing etc. According to the holographic storage application of a genetically mutated bacteriorhodopsin BR-D96N film, this thesis has mainly completed the following works:1. The photochromic property of BR-D96N film is studied. First, the two-state absorption spectra of BR-D96N film were measured. Then, using the Kramers-Kronig relation theory, refractive index variationspectra of the film was calculated from the two-state absorption spectra, which is produced during the photochromic procedure of bacteriorhodopsin. At last, the photochromic spectral dynamics of BR-D96N film is studied, from which the life time of M-state of the film was obtained.2. Depending on the photochromic property of the BR-D96N film, the holographic image storage application is studied. Using BR-D96N film as recording medium, traditional dual-beam interference holographic storage system and collinear holographic image storage system were set up. Comparisons have been done between the reference beam reconstruction and phase conjugated beam reconstruction, between transmission-type holographic recording and reflection-type holographic recording, between different kinds of polarization holographic recording, i.e. parallel linearly, parallel circularly, orthogonal linearly and orthogonal circularly polarized holographic recording etc and between collinear and non-collinear holographic optical storage. At last, rewritable collinear holographic data storage was realized in BR-D96N film, in which the storage density of1.78×104bits/cm2was obtained. 3. The diffraction efficiency of BR-D96N film was studied in detail. The optimum recording time was obtained from the diffraction efficiency dynamic study. The non-destructive readout wavelength area were obtained from calculated the diffraction efficiency spectra. The influence of auxiliary violet light on the diffraction efficiency is measured, and it is shown that using auxiliary violet light the stringent requirements on the exposure time in holographic storage can be reduced.