Holographic gratings were recorded in spirooxazine doped PMMA films by blue-violet laser (405nm), Nd:YAG laser (532nm) and He-Ne laser (632.8nm), respectively. It was found that the photo-dynamics of the holographic grating was dependent on recording wavelength for the photochromic characteristics of spirooxazines. A theoretical description of orientation and isomerization gratings agrees well with the experimental results. It was also found that a pure isomerization grating is formed by two interferential 405nm beams while a mixed grating consisting of isomerization and orientation components is formed by the visible interferential beams (532nm or 632.8nm). Due to the long life of the isomerization gratings, the holographic interference fringes with different periods were clearly observed by Confocal Laser Scanning Microscope.
Multiple holographic gratings were recorded by 405nm laser in the same location of spirooxazine doped polymer films using peristrophic multiplexing techniques. Diffraction efficiency of each grating was controlled almost uniform by adjusting recording time. It was found that the growth rate of the holographic grating recorded later was lower than that of the earlier one, resulting from the decreased population of spirooxazine molecules. A kinetics description for the overlapped isomerization gratings agrees well with experimental results. Due to the thermal stability of the isomerization grating, multiple interference fringes in the photochromic film were reserved and observed by Confocal Laser Scanning Microscope.