V. N. Vasil’ev

Virtual-display optical devices

Modern optical systems of virtual displays are organized on various principles, including holographic, geometrical, and diffraction. This article discusses the most widely used types and features of these systems.

Using prism elements to construct flat waveguide screens

This paper discusses questions of the design of structured optical systems with a periodically repeated group of elements in the form of rhomb–prisms for transmitting an image from a microdisplay to the observer’s eyes. Recommendations are given for selecting the parameters of the prism elements that make up the waveguide screen.

Systems design of augmented-reality collimator displays

This paper describes the optical systems of helmet-mounted augmented-reality displays. Designs are presented that are based both on a nonplanar combiner and a flat combiner that brings a supplementary image into coincidence with an image of ambient space. Examples of systems are given for various implementations that use an opaque image generator.

Modelling interferometric apparatus for recording variable-period Bragg gratings in an optical fiber

This paper discusses a layout for recording variable-period Bragg gratings in optical fibers, based on the use of a modified Talbot interferometer with cylindrical lenses. An analysis is given of how the parameters of the apparatus, including the cylindrical lenses, affect the characteristics of the gratings.

Development and analysis of reflective and catadioptric optical systems for Earth remote sensing

Objectives for Earth remote sensing are traditionally based on reflective or catadioptric optical systems. In this paper, we discuss and describe the characteristics of basic optical systems for Earth remote sensing and provide several sample calculated objectives.

Mechanism for forming internal correlation when concepts are generated on a neural network with connections produced by Fourier holography

The interaction of two competing mechanisms that participate in the formation of a concept is considered in developing an approach to the implementation of inductive generalization in a Fourier-holography setup as a method of generating abstract concepts on the basis of sensory-pattern processing. These mechanisms are nonlinear iterative mapping in the correlation plane, which breaks down the internal correlation of the concept, and diffraction on a rerecorded hologram, which restores the internal correlation. It is shown that the characteristics of the index (reference) pattern that represents reality and the characteristics of the hologram, determined by the properties of the recording medium and by the method of recording it, have an effect on the formation of the internal correlation of the generated concept that prevails over the characteristics of the iterative mapping.

Models of the advancement of hypotheses in a Fourier-holography layout

As applied to the description of a Fourier-holography layout with phase conjugation in the correlation plane as the implementation of a two-layer neural network, this paper discusses two models of the advancement of hypotheses: linear regression of the conditions of a problem from knowledge, and inductive inference. The factors that influence the adequacy of the hypotheses generated for the conditions of a problem are determined and numerically investigated. It is shown that the adequacy of the hypotheses increases as the number of spatial degrees of freedom of the patterns that represent the conditions of the problem (the generalized frequency) increases; moreover, because of internal correlation (as an attribute of the information), increasing the size of the pattern influences the adequacy more effectively than does high-frequency filtering.

Modern video informatics: problems and prospects

This paper discusses modern problems of video informatics in the area of the formation, transmission, processing, analysis, and visualization of video information. The distinguishing feature of video informatics is that it treats these problems from a unified theoretical viewpoint, and this allows the characteristics of video-information systems to be developed and optimized as a unified whole. It is shown to be effective to use a theoretical–informational approach to analyze and optimize video-information systems, starting from the optical channel of radiation propagation in free space when images or multi-dimensional video data are being formed and concluding with the visualization system. Promising directions of further development of the methods of video informatics are highlighted.