Electron micrographs of hologram cross sections

Abstract

The cross sections of both amplitude and phase holograms are observed by electron microscopy. Holograms were recorded on Kodak 649F and Scientia 14C75 sheet films by using a He–Ne laser beam (6328 Å). It is shown that the holograms are recorded throughout the whole thickness of the emulsion layer and the developed grains are enlarged by bleaching (about 1.5 times by length). This enlargement can be correlated with the thickness change of the emulsion layer during the chemical processing in making holograms.

Holographic Sensors: Three-Dimensional Analyte-Sensitive Nanostructures and Their Applications

“…The grain size in a bleached hologram has been shown to be ∼1.5 times larger than that in an unbleached one (Figure 12). 129 This enlargement in the grain size provided an explanation for the increase in the thickness of the emulsion layer after bleaching. The degree of expansion can be expressed as the following:…”

“…C (i.e., 2 for AgBr or AgCl) is the number of silver atoms required to form two molecules of silver halide by the bleaching reaction. The ratio of grain size can be obtained using the following expression: where L Ag 0 and L AgX are the grain sizes of silver (Ag 0 ) and silver halide, respectively. The theoretical calculation of the grain sizes can be used to predict the degree of emulsion swelling after bleaching.…”