DRY PHOTOPOLYMER FILMS FOR COMPUTER-GENERATED INFRARED RADIATION FOCUSING ELEMENTS

A new technological approach makes fabrication of relief computer-gene rated focusing elements for IR radiation by use of a dry photopolymer recording material possible. The formation of a relief structure by se lf-development takes place in the dark, subsequent to the holographic illumination, without wet processing. Consequently these diffractive e lements exhibit low surface scattering. The formation of a surface wav e of the monomer along the light-darkness boundary is observed for the first time to our knowledge and confirms the previously proposed ther modynamic model of the mechanism of the hologram formation in photopol ymerizable layers. Dye-sensitized polymerization of acrylamide is foun d to produce nonlinearity of the relief recording. At least partial co mpensation of this nonlinearity is attained by the introduction of app ropriate corrections into the computer-generated amplitude function. A diffraction efficiency of approximately 55% is obtained for CO2 laser radiation (lambda = 10.6 mum).