Resolution ability of inorganic chalcogenide resists for hologram recording

Subject of study. Unique properties of inorganic photoresists based on chalcogenide glass thin films are studied. Aim of study. Thin film etching processes are studied and a comparison is made between the calculation and experimental results in terms of the relief shape of relief-phase hologram gratings and secure holograms. Method. As-S-Se thin films were obtained via relief-phase thermal evaporation in vacuum. Films were exposed to light with wavelengths of 380, 436, and 488 nm. The film dissolution rate in amine solutions was measured via an interferometric method at a wavelength of 650 nm. Main results. Information obtained regarding the performance of the chalcogenide photoresist for relief-phase hologram recording and for multilayer structures is presented. When recording high-frequency structures with a groove frequency above 2000mm−1, a decrease in resolution is observed when exposed to low-intensity radiation. The mismatch between the expected relief shape and the shape obtained experimentally can be explained using diffusion of excited electrons from irradiated areas to dark areas during exposure. This effect facilitates the recording of holograms onto multilayer structures comprising chalcogenide layers with different compositions and photosensitivity values. For example, based on the unique properties of the chalcogenide photoresist, multilayer relief structures can be obtained, thereby enabling the production of color images in the zero order of diffraction. Practical significance. The use of chalcogenide glass photosensitive films for the recording of diffraction grating profiles facilitates the production of large-sized optical elements. Furthermore, the electron–hole pair diffusion effect enables the recording of copyable relief-phase elements with color images in the zero order of diffraction.