Appl Opt. 1999 Dec 11;38(35):7222-7. doi: 10.1364/ao.38.007222.
Applied optics
R Grzymala, T Keinonen
PMID: 18324270 DOI: 10.1364/ao.38.007222
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.
