Patent EA-002393-B1 (EA)
Title: Transparent and semitransparent difractive elements, particularly holograms and their making progress
Inventor: VLCEK MIROSLAV
IPC: G11B7/24003
Filed: 1999-03-11
Abstract: 1. Transparent and semitransparent diffractive elements, particularly holograms, consisting at least of two layers with a different index of refraction, whereof a first bearing layer (1) is a transparent polymer or copolymer having index of refraction lower than 1.7 and on said first bearing layer is deposited a second holographic effect enhancing high refraction index layer (2) constituted by substances based on chalcogenides with an index of refraction higher than 1.7 and a melting temperature lower than 900 degree C, characterized in that the first diffractive pattern is mechanically shaped in the bearing layer (1) and/or in the second layer (2) and at least one further second diffractive pattern is formed in the second layer (2), selected from the group of binary, ternary and even more complex chalcogenide and/or chalcohalogenide systems, containing at least one element selected from the group comprising S, Se or Te, and also elements selected from the group comprising Cu, Ag, Au, Hg, B, Al, Ga, In, Tl, Si, Ge, Sn, Pb, N, P, As, Sb, Bi. 2. Transparent and semitransparent diffractive elements according to claim 1, characterized in that the chalcogenide based substances also contain at least one transient metal and/or at least one element from the rare earth element group. 3. Transparent and semitransparent diffractive element according to claims 1 or 2. characterized in that it also consists of a protecting layer (6) and/or an adhesive layer (7) and /or a fragile layer (8) and/or anchoring layer (8). 4. A production process of transparent and semitransparent diffractive elements according to claims 1 to 3 in which the first diffractive pattern is shaped in the said bearing layer (1) and subsequently on said bearing layer (1) the second layer (2) is deposited, characterized in that the second diffraction patterns are formed in the said high refraction index layer (2). comprising one or more layers chaicogenide based substances of different composition, which can be deposited subsequently or simultaneously. 5. A production process according to claims 1 to 3. characterized in that the second layer (2) is first deposited on the transparent bearing layer (1) and only after that the first diffractive pattern is mechanically shaped in said second layer (2) and/or both said layers and after that the second diffractive pattern is formed in the said to exposure sensitive high refraction index layer (2). 6. A production process according to claims 4 or 5, characterized in that the second layer (2) is deposited on said bearing layer (1) coloured in advance. 7. A production process according to any of claims 4 to 6, characterized in that the high refraction index layer (2) is deposited under low pressure, e.g. by vacuum evaporation, sputtering or chemical vapour deposition (CVD) technique. 8. A production process according to any of claims 4 to 6, characterized in that the high refraction index layer (2) is deposited on the bearing layer (1) under atmospheric pressure, e. g. by spraying, painting or spinning coating method. 9. A production process according to any of claims 4 to 8. characterized in that the further second diffractive pattern is formed in the second layer (2) consisting of chalcogenide based substances by exposure and/or selective etching and/or photo- and/or thermally induced metal diffusion and/or with a halogen or oxygen implantation into the second layer (2) by its interaction with halogene vapours or interaction with oxygen or through air hydrolysis.