The article presents the development of a software tool for modeling the influence of physical processes occurring in a single-mode optical fiber as a result of bending deformation. Model of bending deformation of single-mode optical fiber is considered. Classical and refined models of deformation and their influence on the optical fiber params are given. The initial data required to implement the software tool is discussed in detail. The development of the modeling program was gradually considered. The specifics of the implemented program obtained during the computational experiment are indicated.

Keywords: mathematical modeling, optical fiber, bending deformation, modeling of deformed fiber behavior, computational experiment, software

The paper considers a model of a multi-aperture wave-front sensor for an active laser beam control system based on the iterative image reconstruction algorithms with limitations, particularly, on the Gerchberg-Saxton algorithm. The specifics of these algorithms is the presence of the so-called divergence factor which is characterized by obtaining “successful” and “unsuccessful” solutions, and may be clarified by stagnation conditions available (or by local extrema). The use of global optimization methods allows to avoid this constraint and to build quite an effective strategy for retrieving phase information. An experimental research was conducted to restore phase information using this method. For this purpose, a model of a seven-channel laser system with a different phase shift was developed.

Keywords: multichannel laser systems, wavefront sensor, Gerchberg-Saxton algorithm, physical modeling, image reconstruction, phase retrieval

A method for recording holograms using digital cameras with high spatial resolution is considered. To register holograms obtained in optical setups with an inclined reference beam, a high resolution of registration systems is required. To do this, it is necessary to use media with a resolution of 2000-4000 lines per mm. The use of photographic plates requires a fairly long exposure and development time, which is usually done separately from the optical setup. In the case of holographic interferometry systems, it is necessary to provide for mounting the hologram back into the optical setup with sufficiently high accuracy. Therefore, digital holography methods have been developed to record holograms on photomatrices with limited resolution. These methods are based on the use of optical schemes at small angles (less than 5 degrees) between interfering beams. Recently, sensors with a single element size of 1.33 µm and 0.56 µm have appeared. This resolution makes it possible to return to registration schemes with angles between interfering beams of 30-60 degrees. This allows us to hope for the revival of holographic methods and methods of holographic interferometry at the modern level without the use of intermediate recording media.

Keywords: holography, holographic interferometry, photomatrices with high spatial resolution, holography with an inclined reference beam, digital holography, Fourier transform

The article presents and substantiates the structure of the original combined pathospecific measuring device for the diagnosis of glaucoma, which will allow for a comprehensive analysis of the hydro- and hemodynamics of the eye and thereby improve the quality of glaucoma diagnosis. Based on this structure, a detailed metrological analysis of this installation as a means of biomedical measurements was given in the work. Brief conclusions on the work are given and prospects for the further development of the project are determined.

Keywords: combined pathospecific measuring device, tonometry, rheography, sphygmography

Methods for determining the position of the center of gravity and the static stability margin of an aircraft in flight are considered. Based on the analysis of the motion of an aircraft as a rigid body, possible methods for determining the position of the center of gravity are determined and their errors are calculated. Comparison of the errors of various methods made it possible to conclude that it is expedient to use a method based on the use of information on the fuel reserve.

Keywords: center of gravity, moments of inertia of the aircraft, free vibrations, fuel consumption