In this paper

the author proposes a new protest for unbleached holograms on the silver halide medium

essentially consisted of phase type

though previously of amplitude type. This hologram has been acquired through practice by the author

and applied to the original hologram and also the replica for "the hologram micro-fiche storage systems with a large capacity". Both the original characteristics of the previous unbleached amplitude silver hologram and the efficiency of the similar bleached phase silver halide hologram are available in this new unbleached hologram. The 1st order diffraction efficiency measured of this new unbleached grating is about 20%

but the previous unbleached theoratical diffraction efficiency is 6.3% only. 10

000 alphabets or 3

500 Chinese characters or -1×105 bits can be stored and replicated in a small circle about 1mm in diameter. The reconstructed image is very clear and without speckle noise. These holograms show extremely good light stability.