S. I. Yakubov, M. V. Bretsko, S. I. Khalilov, Ya. E. Akimova, D. V. Maksimov
{"title":"Self-Healing of the Polarization Structure in Vector Beams Subjected to Sector Perturbation","authors":"S. I. Yakubov, M. V. Bretsko, S. I. Khalilov, Ya. E. Akimova, D. V. Maksimov","doi":"10.3103/S1060992X25700249","DOIUrl":"10.3103/S1060992X25700249","url":null,"abstract":"<p>This paper presents a theoretical and experimental investigation of the influence of sector perturbations on the polarization structure of azimuthal and radial modes. To quantify the degree of polarization restoration, an integral metric based on normalized Stokes parameters is introduced. Numerical simulations demonstrate that for small sector angles, the polarization structure recovers at propagation distances exceeding the Rayleigh length. As the sector angle increases, only partial restoration is observed. Although the radial mode exhibits locally more stable polarization behavior, the integral restoration metric shows only minor differences compared to the azimuthal mode. The results are supported by experimental data and are in good agreement with the theoretical model.</p>","PeriodicalId":721,"journal":{"name":"Optical Memory and Neural Networks","volume":"34 2","pages":"S207 - S220"},"PeriodicalIF":0.8,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146043482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Characterization of Resonance Multimode Planar Structures Based on Transfer Matrix Method","authors":"D. V. Nesterenko, V. A. Soifer","doi":"10.3103/S1060992X25602015","DOIUrl":"10.3103/S1060992X25602015","url":null,"abstract":"<p>We propose an approach for obtaining analytical expressions approximating asymmetric resonances in the spectra of multimode layered structures, where elements of the structure support excitation of plasmonic modes. The 2 × 2 transfer matrix method is used to form a composite matrix describing the field amplitudes in such a structure element. The coefficients of the composite matrices are represented by analytical expressions describing the interference of the resonance and non-resonance components. The applicability of the proposed approach is demonstrated in the case of coupling of two plasmonic modes in a multilayer metal-dielectric structure.</p>","PeriodicalId":721,"journal":{"name":"Optical Memory and Neural Networks","volume":"34 2","pages":"S252 - S258"},"PeriodicalIF":0.8,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146043414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. V. Kotlyar, A. A. Kovalev, A. M. Telegin, S. S. Stafeev
{"title":"Classical, Polarization, and Hybrid Orbital Angular Momentum of Vector Fields with Polarization Singularities","authors":"V. V. Kotlyar, A. A. Kovalev, A. M. Telegin, S. S. Stafeev","doi":"10.3103/S1060992X2560209X","DOIUrl":"10.3103/S1060992X2560209X","url":null,"abstract":"<p>Besides scalar optical vortices that have a topological charge (TC), helical wave front, and carry an orbital angular momentum (OAM) that can be transferred to particles and rotate them along circular trajectories, polarization optical vortices are also known, whose polarization state in the beam section changes with the azimuthal angle. Such vortices are polarization singularities that are described by indices, similar to the TC. However, polarization OAM for polarization vortices still has not been considered, although laser beams with inhomogeneous polarization can perform spiral mass transport in polarization-sensitive media. In this work, we introduce and consider two analogues of the OAM for vector fields. One polarization OAM analogue is the polarization orientation azimuthally changing velocity, or polarization OAM (pOAM), whereas the hybrid OAM analogue is the polarization ellipticity azimuthally changing velocity, or hybrid OAM (hOAM). For instance, we demonstrate that the normalized pOAM is equal to the order of a cylindrical vector beam and also equals the order of Poincaré beam. In optical material processing, the considered OAM analogues describe how light fields with different polarization affect polarization-sensitive media. In optical data transmission, these OAM analogues allow distinguishing different light fields that are indistinguishable by their conventional OAM.</p>","PeriodicalId":721,"journal":{"name":"Optical Memory and Neural Networks","volume":"34 2","pages":"S292 - S300"},"PeriodicalIF":0.8,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146043476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. V. Bretsko, S. I. Yakubov, D. V. Maksimov, S. I. Khalilov, Ya. E. Akimova, A. O. Titova
{"title":"Polarization Singularities in Non-Coaxial Interference of Vector Beams","authors":"M. V. Bretsko, S. I. Yakubov, D. V. Maksimov, S. I. Khalilov, Ya. E. Akimova, A. O. Titova","doi":"10.3103/S1060992X25602283","DOIUrl":"10.3103/S1060992X25602283","url":null,"abstract":"<p>The paper investigates the formation of polarization singularities arising from the non-axial interference of vector optical modes of different symmetry. An analytical model of superposition of two spatially shifted beams with arbitrary topological charges and phase parameters is proposed. It is shown that in the region of their overlap polarization features of the V- and C-points type as well as stable configurations of the lemon and star types can arise. On the basis of the Stokes parameters, the features are classified and the conditions of their formation are determined. An analytical relation determining the optimal value of beam displacement for the appearance of a symmetric singularity is proposed. The results are confirmed by numerical modelling and experiment.</p>","PeriodicalId":721,"journal":{"name":"Optical Memory and Neural Networks","volume":"34 2","pages":"S196 - S206"},"PeriodicalIF":0.8,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146043412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Bessel Beams in Crystals with Optical Activity","authors":"Y. Egorov, V. Mostovskoy, E. Umerov, A. Rubass","doi":"10.3103/S1060992X25602258","DOIUrl":"10.3103/S1060992X25602258","url":null,"abstract":"<p>When considering optical beams propagating in media with optical activity, using the example of a structurally stable Bessel-Gauss launch, it is shown that in media without active birefringence, it is possible to create a single optical vortex in one of the polarization components of the beam. Mutual transformation between the components is due to the optical activity of the medium for both azimuthal and radial field components. The stable state of the isotropic point is due to the absence of external disturbances of the beam, and in the presence of external disturbances by the active medium, the isotropic point is destroyed. Linear activity and the presence of birefringence are related to each other and affect the isotropic point. The structure of fields in a medium with optical activity is very similar to the structure of Bessel-Gauss beams and can be controlled by them using external disturbances.</p>","PeriodicalId":721,"journal":{"name":"Optical Memory and Neural Networks","volume":"34 2","pages":"S266 - S277"},"PeriodicalIF":0.8,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146043415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
V. E. Dementyev, A. G. Tashlinskii, I. V. Chufarov, A. P. Tereshenok, S. N. Potapov
{"title":"Using Computer Vision Methods for AlSiC Products Quality Control","authors":"V. E. Dementyev, A. G. Tashlinskii, I. V. Chufarov, A. P. Tereshenok, S. N. Potapov","doi":"10.3103/S1060992X25700250","DOIUrl":"10.3103/S1060992X25700250","url":null,"abstract":"<p>This paper explores the application of computer vision for quality control of products, focusing on the challenge of surface defect detection with a limited dataset. Substrate made of AlSiC composite material is a good example. To address the small sample size, data augmentation and transfer learning techniques have been employed, pre-training a model on a public crack dataset. The core of approach is utilization of the YOLOv8-OBB object detector, chosen for its support of oriented bounding boxes, which are crucial for accurately capturing elongated defects like cracks. Furthermore, to enhance detection reliability, a method that combines results from multiple images of the same object captured from different angles has been proposed. This multi-view analysis allows for a reduction in the detection confidence threshold, increasing the true positive rate. Therefore, offered technique in article is a combination of YOLOv8-Obb, Augmentation, Transfer Learning and Multi-View Analysis. The proposed system was tested on a dedicated dataset of AlSiC products, achieving a defect detection rate of over 80% with a false alarm probability of approximately 1%. The results demonstrate the feasibility of using modern neural network-based detectors for automated visual inspection in specialized industrial applications.</p>","PeriodicalId":721,"journal":{"name":"Optical Memory and Neural Networks","volume":"34 2","pages":"S301 - S311"},"PeriodicalIF":0.8,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146043475","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Methods of Spectral Matching for Remote Sensing Data","authors":"A. Borisov","doi":"10.3103/S1060992X25602398","DOIUrl":"10.3103/S1060992X25602398","url":null,"abstract":"<p>Three methods of spectral matching for remote sensing data are studied: a pixelwise linear method, a pixelwise nonlinear method and a generalized nonlinear method. Nonlinear methods are implemented as a pair of multilayer perceptrons and a pair of convolutional neural networks respectively. Training and comparison of methods are performed using Landsat-8 and Sentinel-2 remote sensing images from 2021 IEEE GRSS Data Fusion Contest dataset. The root mean squared error (RMSE), the normalized mutual information (NMI) and the structural similarity index measure (SSIM) are used as metrics. A generalized nonlinear method demonstrates the best quality of spectral matching, achieving average values of RMSE = 0.048, NMI = 1.194 and SSIM = 0.887 over the testing set. A linear pixelwise method achieves RMSE = 0.075, NMI = 1.118 and SSIM = 0.847, a nonlinear pixelwise method achieves RMSE = 0.074, NMI = 1.117 and SSIM = 0.843. All methods show a significant improvement when compared to results without spectral matching (RMSE = 0.158, NMI = 0.119, SSIM = 0.585).</p>","PeriodicalId":721,"journal":{"name":"Optical Memory and Neural Networks","volume":"34 2","pages":"S221 - S229"},"PeriodicalIF":0.8,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146043397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. A. Yarunova, D. S. Riashchikov, A. A. Krents, N. E. Molevich
{"title":"Complex Spatial Structures in the Optically Driven VCSELs","authors":"E. A. Yarunova, D. S. Riashchikov, A. A. Krents, N. E. Molevich","doi":"10.3103/S1060992X25601927","DOIUrl":"10.3103/S1060992X25601927","url":null,"abstract":"<p>This study investigates the spatiotemporal dynamics of broad-area vertical-cavity surface-emitting lasers (VCSELs) under external optical injection. Using a semiconductor-adapted Maxwell-Bloch model, we demonstrate that weak optical injection effectively suppresses modulation instability—a major constraint to achieving coherent VCSEL emission. Through linear stability analysis and numerical simulations, we found and showed the dependence of spatial patterns on pump current and injection amplitude. Our results reveal that controlled optical injection transforms chaotic emission into ordered structures, including stripes, hexagons, labyrinths, and their hybrid forms, with the pattern scale governed by the wavenumber of maximum growth increment. Notably, reducing the laser aperture size promotes the formation of defect-free patterns. These findings offer key insights for stabilizing VCSEL emission and leveraging self-organized patterns for advanced photonic applications, such as optical computing and on-chip communication systems.</p>","PeriodicalId":721,"journal":{"name":"Optical Memory and Neural Networks","volume":"34 2","pages":"S346 - S356"},"PeriodicalIF":0.8,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146043398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Axial and Off-Axis Focal Diffraction Orders Formation Using of Phase Quantized Non-Paraxial Optical Elements","authors":"O. A. Dyukareva","doi":"10.3103/S1060992X2560199X","DOIUrl":"10.3103/S1060992X2560199X","url":null,"abstract":"<p>In this paper, we consider the beam diffraction on quantized non-paraxial optical elements. We show that the formation of diffraction orders depends on both the numerical aperture and the focal length. In non-paraxial propagation, the main energy falls on the first diffraction orders, and it is also possible to eliminate a larger number of orders compared to the paraxial case. To simultaneously increase the number of longitudinal and transverse orders in the non-paraxial region, we propose using multifocal lenses as focusing elements. We expect that the results obtained can be used in (de-)multiplexing and signal detection problems.</p>","PeriodicalId":721,"journal":{"name":"Optical Memory and Neural Networks","volume":"34 2","pages":"S243 - S251"},"PeriodicalIF":0.8,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146043479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Feature Selection for Thick Cloud Classification","authors":"A. S. Minkin","doi":"10.3103/S1060992X25602520","DOIUrl":"10.3103/S1060992X25602520","url":null,"abstract":"<p>A method of feature selection based on hyperspectral data classification is proposed. The features are selected using iterative training of Decision Tree classifiers for further construction of a thick cloud classifier based on spectral features. Classifiers are trained with different hyperparameters for different set of features by recursive elimination. Feature selection is determined by analyzing the correlation between the decrease in Gini impurity and classification accuracy, combined with mean feature importance. Classification model training is performed for three types of surfaces: ocean, vegetation, and urbanized areas. Feature selection improves the accuracy of Random Forest classifier by choosing a limited set of features from the NIR and the lower part of the SWIR spectrum ranges according to their importance.</p>","PeriodicalId":721,"journal":{"name":"Optical Memory and Neural Networks","volume":"34 2","pages":"S327 - S332"},"PeriodicalIF":0.8,"publicationDate":"2026-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146043480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}