Methylene-blue sensitized dichromated gelatin: wide-range colour adjustment of reflection hologram

摘要

In this paper a new technique is presented for adjusting the playback wavelength of reflection holograms recorded in methylene-blue sensitized dichromated gelatin (MBDCG). During the fabrication of the MBDCG medium, a water-soluble organic reagent is introduced homogeneously into the photosensitive layer as a preswelling reagent and wavelength adjuster. This method has a wide wavelength adjustment range (up to 200 nm, almost covering the entire visible spectral region), high diffraction efficiency and signal-to-noise ratio, and can be applied to quantitatively adjust the playback wavelength of reflection hologram by changing the concentration of the preswelling reagent. Its possible applications include colour image display, holographic optical elements, optical communication and optical anti-counterfeiting.