Production quantities of a multi-element holographic scanner disc are made by optically replicating a silver halide master disc one element at a time in a dichromated gelatin film. The dichromated gelatin film swells during processing. The swell is monitored during production by determining the shift...http://www.google.com.tw/patents/US4416505?utm_source=gb-gplus-share專利 US4416505 - Method for making holographic optical elements with high diffraction efficiencies
