Investigation Of Organic Photochromic Materials In Holography And Optical Information Processing

Organic photochromic materials have many excellent properties which have applied in the field of information processing and optical storage. The mainly work in this paper is about two kind of materials - bacteriorhodopsin(BR) and fulgide. The photochromic and photoinduced anisotropy properties of both materials and the applications of them in the field of information processing and optical storage were studied. The following are the achievement.1. The photochromic properties of BR and fulgide films were studied. The first-order approximation formulae, numerical calculation and experiential formulae methods were used to analyze the photochromic properties of materials and fit the transmission kinetic curve, the photochemical reaction constant γ of different wavelengths were obtained. It demonstrated that the transmission kinetic curve of BR is intensity depended while fulgide is exposure depended. The transmission kinetic curve in red light and green light will be effected by the irridation of purple light. Both materials have the saturation absorption.2. The characteristic of the photoinduced anisotropy of two materials were studied. The dichroism kinetic curve of fulgide film was theoretical calculated according to first-order approximation formulae. The results demonstrate that the perpendicular polarization UV light can improve the photoinduced anisotropy of red light. The photoinduced absorption and refractive index change between two states were similar to the dichroism and birefringence spectrum showed that mechanism of the photoinduced anisotropy is result from the polarization exciting.3. The holography characteristics of the materials were studied. The optical storage properties of both materials were compared such as sensitive spectral range, sensitivity, spatial resolution, fatigue resistance and thermal stability. The polarization state and the diffraction efficiency in different polarization holography were analyzed. The diffraction efficiency kinetic curve of both films were theoretical calculated according to first-order approximation formulae and numerical calculation The hologram is recorded based on the photochromic and photoinduced anisotropy properties. Due to overexposure, the hologram is recorded in nonlinear area, the distribution of the transmission of the holographic gratings deviates from the cosine-like shape. As a result, the diffraction efficiency is very low. The kinetic curves of diffraction efficiency were fit with first-order approximation formulae, numerical calculation and experiential formulae methods. It is proved by experimental result and theoretical calculate that proper auxiliary irradiation of 405nm violet light will improve the diffraction efficiency, the distribution of the transmission of the holographic gratings back to cosine-like shape. It is discussed that the recording...