Holographic Image Storage With BR-D96N Film

Bacteriorhodopsin(BR) is a biologically active photosensitive protein, which has many excellent optical properties. Because of its excellent photochromic properties, it becomes one of the important materials in the field of optical signal processing and optical storage. Holographic optical storage is one of the major candidates, which belong to the fourth generation of ultra-fast ultra-high density optical information storage technology. And it is also the most promising and most practical storage technology, which is vigorously developed currently. Although the write-ones-read-many type holographic video disc (HVD-WORM) and its holographic storage driver have been developed, but the ultra-high-density rewritable holographic disc storage (HVD-RW) is still a hot topic in this field. Focusing on the photochromic properties (mainly photochromic property) and its rewritable holographic storage applications of a genetically modified bacteriorhodopsin (BR-D96N) film, the author mainly completed the following works:1. The photochromic properties of BR-D96N film were studied:The absorption spectra of the two states were measured; and then the spectrum of refractive index changing appearied during the photochromic reaction in this film is calculated according to the Kramers-Kronig transformation.2. Ordinary holographic and polarization holographic applications of BR-D96N film samples were realized by using its photochromic and photoinduced anisotropy properties. First of all, several holographic storage properties of BR-D96N film sample were experimentally measured and theoretically calculated:The diffraction polarization state and diffraction efficiency of different kinds of polarization holograms were theoretically analyzed and deduced; and then based on the photochromic property of BR-D96N film the spectrum of ordinary holographic efficiency was theoretically calculated by using MATLAB softwere; and then the storage rate, fatigue resistance and thermal stability of the BR-D96N film were measured qualitatively.3. Different kinds of holograms were recorded in a BR-D96N film by using the traditional double-beam holographic storage optical setup (non-collinear holographic storage), including transmission-tape holographic recording and reflection-tape holographic recording hologram, reference beam reconstruction and phase conjugated beam reconstruction hologram, and different kind of polarization holographic recording hologram (parallel linear polarization holographic recording, orthogonal linear polarization holographic recording, parallel circular polarization holographic recording and orthogonal circular polarization holographic recording). The diffraction efficiencies and diffractive images'signal-to-noise-ratios (SNR) of different kinds of holograms are compared. And the effections of phase conjugated beam to increase the SNR and to correct the phase aberration caused by the mis-adjustment of optical setup were also studied.4. Collinear holographic image storage was realized in a BR-D96N film. Compared with non-collinear holographic storage, in collinear holographic storage system, small volume, low environmental effect and the high density storage were realized, but the SNR of the diffractive images was low.