Search academic texts

Information × Registration Number 0226U000470, (0125U001789) , R & D reports Title To improve and investigate methods for eliminating defects in diffractive elements fabricated by direct laser writing popup.stage_title Дослідження методів вилучення дефектів, контроль зображень та статистичний аналіз модуляційних дисків після лазерного запису. Head Dmytrenko Oleh O., Registration Date 10-01-2026 Organization Institute for Information Recording NASU popup.description1 The improvement of methods for detecting and removing defects on the surface of modulation disks obtained by direct laser recording is the main objective of this study. To achieve this, an analysis of the defect size distribution will be conducted, the causes of the formation of darkened areas in images will be investigated, and methods for removing opaque defects using focused laser pulse irradiation will be developed and studied. The expected results of this work will contribute to enhancing the quality and reliability of modulation disks during their manufacturing and operation. popup.description2 The research is devoted to the improvement and investigation of methods for detecting, analyzing and eliminating defects in diffractive elements manufactured by direct laser recording. The main attention is paid to opaque defects in the information structure of modulation and code disks, in particular, residues of metal films, point inclusions, linear and bridge defects, which significantly affect the optical and metrological characteristics of products. An approach to automated defect control using optical microscopy in bright and dark fields and algorithmic image processing with subsequent morphological and statistical classification has been developed. A statistical analysis of the distribution of defects by shape, size and spatial localization on the disk surface has been performed. Experimental studies of the possibilities of selective local removal of opaque metal defects by laser ablation have been conducted. It has been shown that under appropriate conditions of laser exposure, defects can be removed without damaging the substrate microrelief. To substantiate the safe ranges of parameters, thermal processes during irradiation have been simulated. The results obtained form a scientific and methodological basis for improving the quality and reliability of diffractive optical elements and outline further research directions related to the refinement of processing conditions and the assessment of the prospects for the practical implementation of selective laser technologies for defect removal. Product Description popup.authors Butok Oleksandr M. popup.nrat_date 2026-01-10 Close