Dark self-enhancement in dichromated-gelatin gratings: a detailed study.
Strong dark self-enhancement, the increase in diffraction efficiency after irradiation, has been reported previously for dichromated-gelatin gratings. Here a more-detailed study of this self-enhancement effect is presented. The self-enhancement in dichromated-gelatin gratings was of the order of 10-100, depending on the pH and on the dichromate concentration of the solution used for the preparation of dichromated-gelatin films. The highest self-enhancement gain occurred when pH was high and dichromate concentration was low. The increase in the diffraction efficiencies of the gratings continued over 3 months.
Grzymala
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University of Joensuu, PO Box 111, FIN-80101 Joensuu, Finland. Tuula.Keinonen@joensuu.fi
Keinonen
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