Mixed phase-amplitude holographic gratings recorded in bleached silver halide materials

Abstract

The coupled wave theory of Kogelnik has given a well-established basis for the comprehension of how light propagates inside a volume hologram. This theory gives a good approximation for the diffraction efficiency of both volume phase holograms and volume absorption holograms. Mixed holograms (phase and absorption) have also been dealt with from the point of view of the coupled wave theory. In this paper we use Kogelnik's coupled wave theory to give quantitative information about the mechanisms which produce mixed gratings in photographic emulsions. In particular, we demonstrate that mixed amplitude-phase gratings are recorded on photographic emulsions when fixation-free bleaching techniques are used to obtain volume holograms. We will prove that the oxidation products of the bleach can give rise to an absorption modulation at high values of exposure and high concentrations of potassium bromide in the bleach bath. We will also give quantitative data regarding the absorption created by these oxidation products.

Experimental evidence of mixed gratings with a phase difference between the phase and amplitude grating in volume holograms

“…Although fixation-free rehalogenating bleaches are generally known for creating pure phase holograms [9,[13][14][15][16], the oxidation products of the bleach can give rise to an absorption modulation at high values of exposure and high concentrations of potassium bromide in the bleach bath. Experimental confirmation of this fact can be found in reference [17]. In this reference, mixed gratings without dephasing between the amplitude and phase gratings were analyzed.…”

Temporal evolution of the angular response of a holographic diffraction grating in PVA/acrylamide photopolymer

“…Here also there is asymmetry in the angular response. This type of phenomenon has been widely studied in photographic emulsions [12] and is due to the fact that with high index modulations, not only is there a phase grating but also a small amplitude modulation (absorption coefficient modulation, α) [13,14]. Therefore, in order to carry out a more precise fitting, this should be done based on the mixed gratings theory.…”

Ab Initio Study of Neutral and Charged Copper Bromide (CuBr) n (+) Clusters (n = 1–6)

“…The removal of one electron yields to lower spatial symmetry, but the linear BrCuBr subunits and bent CuBrCu ones are still present. The lowest-energy isomer of (CuBr) 2 ? is quasi linear with a BrCuBr linear subunit and a bent CuBrCu subunit (with an angle of 104°).…”

“…The halides of noble metal have attracted much interest both by experiments and computations, in particular due to many practical applications such as the use of silver bromide in photography [1] and holography [2] or the use of copper halides as catalysts [3]. In a more fundamental point of view, the interactions between halide and noble metal atoms are difficult to characterize.…”