| abstract |
High photographic speed photoresists based on N-vinyl monomers are made capable of exhibiting broad spectral response between at least 3200 A and up to 11,000 A without loss of speed by incorporating therein one or more specific bleachout dyes. Any color produced as a consequence of exposure and development may be eliminated by blanket exposure after fixing to light or to a combination of light and heat. While these photoresist compositions are particularly suitable for the formation of relief phase holograms, generally called thin film surface reflection type holograms, thick phase holograms, optical components such as diffraction gratings, holographic tape for video cassette recording, microfiche type holograms and similar devices where the absence of color in the developed and fixed resist is important, these compositions are also suitable for the preparation of patterns whereby after suitable development, photomechanical milling may be accomplished for printing plates, printed circuits, microelectronic circuits and general chemical milling of metals, plastics and glass where the original pattern is formed in the photoresist placed on a suitable surface by the medium of scanning with a modulated or unmodulated laser beam of chosen wavelength and of relatively low power. The majority of applications, particularly photomechanical milling, require wet development. A significant property of these broad spectrum response photoresists is that they may be processed completely dry without the need for wet development and still yield high quality relief phase holograms both for holographic purposes and for formation of optical components and still retain the potential for complete bleaching of the sensitizing agents by treatment with ultraviolet light with or without the presence of heat or visible or other type of light representing the peak response of the bleachout dye at which wavelength the bleachout dye bleaches most rapidly. |