Guo Lurong

Methylene-blue-sensitized dichromated gelatin holograms with antihumidity polymer coatings

An efficient method of resisting humidity for methylene-blue-sensitized dichromated gelatin (MBDCG) holograms is reported. The method uses a viscous liquid pure poly(styrene) solution with a low degree of polymerization as the coating material. On the basis of this coating, the diffraction efficiency of treated MBDCG holograms exposed to a high-humidity (relative humidity of 80-85%) environment was not obviously changed during observation over 3 mon.

Photoetching cellulose-film recording material and fabrication of double-faced micro-optical elements.

A novel, to our knowledge, polymer-type holographic and photoetching recording material-photoetching cellulose film-is reported. Its basic photochemical reaction scheme and the mechanism of image formation are discussed with respect to electron-spin resonance spectra and infrared spectra. Meanwhile, its characteristics, such as a strong real-time effect, high spatial resolution, linear surface-relief modulation capacity, and delayed development effect, are investigated experimentally. Finally, taking advantage of its double-faced photosensitivity, we fabricate integrated micro-optical elements that have both the functions of beam splitting and focusing.

π-Phase filtering of the zero-frequency spectral component and pseudocolor encoding

The basic problem of obtaining contrast reversal by pi-phase filtering of an image is discussed, and the condition for obtaining contrast reversal is deduced. Computer-simulation results are presented. These-show that, in general, within a certain density range pi-phase filtering produces contrast reversal, that this reversal is strongly dependent on the width of the filter, and that this filtering will cause deformation of density in pseudocolor encoding. The effect of the width of the filter and the density distribution of the image on encoding deformation and the density range of contrast reversal is demonstrated.