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The comparison between the NCTU and Caltech PQ-PMMA material shows that the difference in their behavior lies in the different concentration of residual MMA in the samples. Experimental evidence shows that during recording, PQ molecules attach to MMA but no diffusion takes place at room temperature. However, the excess of monomer during recording enables photoinduced polymerization as a mechanism for hologram formation leading to high diffraction efficiencies without the need of baking. The grating formed by the PQ-MMA groups is unstable and it can be erased within a few hours of baking.

We present dynamics of the grating formation process in phenanthrenequinone- (PQ-) doped poly(methyl methacrylate) (PMMA) photo-polymer. The exposure schedule for multiplexing holograms to achieve equal-strength storage in a single location is described. The analysis method is valid for any saturated media, thus the results can be applied to other photo-polymer materials with similar kinetics.

In this paper, we present investigations on holographic data storage using photopolymer of poly(methyl methacrylate) (PMMA) doped with phenathrenequinone (PQ) molecules. From the system specifications we derive the material parameters that are required for a data storage system. We present a technique of material preparation for obtaining samples with good optical quality. Then we present material characteristics for holographic data storage, including M/#, sensitivity, and material shrinkage. Experimental demonstration on digital data storage is presented and bit error rate is discussed.

We present the design and fabrication of a phenanthrenequinone-doped poly(methyl methacrylate) photopolymer material. Large blocks of samples were made, and the material showed negligible shrinkage after optical exposures. We recorded and reconstructed 250 holograms at a single spot, using a 1-cm(3) block.