Using holographic recording technology, two kinds of transient diffraction gratings were demonstrated in azo-dye doped Poly(methyl methacrylate) (PMMA) films and bulk matrices respectively. In PMMA films containing azo-dye Disperse Red 13 (DR13), the refractive index gratings came from the reorientation of azo-dye molecules in different areas with different polarization distribution of recording beams. The characteristics of the transient gratings in films samples which were recorded by two mutually parallel polarization beams (PP and SS) as well as orthogonal linear polarization beams (PS and ±45°) from an Ar ion laser (514nm) were investigated by monitoring the first order diffraction intensity of the readout He-Ne laser beam (632.8nm). With the interaction of bi-photonic lights at 514nm and 632.8nm, the transient gratings in azo-dye DR13 doped PMMA bulk matrices was a kind of population gratings of Trans and Cis isomers, which was attributed to the weak absorption of Cis isomers at 632.8nm and the positive dichroism of Trans isomers at 514nm. Furthermore, the all-optical switching behavior of the two kinds of transient holographic gratings were observed repeatedly by turning on and off the writing beams, and a response time at the magnitude of ten milliseconds order could be obtained.
High-density optical storage and the three-dimension (3D) microstructures in the side-chain azobenzene polymer material were studied. Two interfering orthogonal (± 45° to the incident plane) linearly polarized laser beams from an Ar+ laser at 514.5 nm as recording beams intersected on the surface of the sample with an angle which could be adjusted to form the holographic gratings storage. And a He-Ne laser at 633nm was used for a reading beam. By rotating the sample, there were 20 sets of gratings stored on the same spot in a side-chain copolymer PGMAA-20 film. Utilizing the stable optical storage property of this material, a rectangular microstructure and a complicated double layers nesting six-pointed star microstructure were also inscribed in the samples by using the same simple two-wave couple (TWC) setup in regular recording sequence, including rotating the sample and adjusting the incident angle of the recording beams. In the recording process of the high-density multiple gratings structure with different periodicity and incident angle, we found that the recording order of gratings with different periodicity made a crucial effect on the final forming of the microstructures. The microstructures in the samples were shown by an optical phase contrast microscope (Nikon TE300). And the simulation results were in accordance with what we had observed through a microscope.