Optoinformation method of subdiffraction angular measurements

 Борейшо А.С., Савин А.В., Страхов С.Ю., Ершов А.Г., Суханов Г.А., Джгамадзе Г.Т., Сотникова Н.В. Оптоинформационный метод субдифракционных угловых измерений // Оптический журнал. 2024. Т. 91. № 12. С. 13–23. http://doi.org/10.17586/1023-5086-2024-91-12-13-23

Boreisho A.S., Savin A.V., Strakhov S.Yu., Ershov A.G., Sukhanov G.A., Jgamadze G.T., Sotnikova N.V. Optoinformation method of subdiffraction angular measurements [in Russian] // Opticheskii Zhurnal. 2024. V. 91. № 12. P. 13–23. http://doi.org/10.17586/1023-5086-2024-91-12-13-23

Subject of the study. Optical-information method for angle measuring between a laser beam and the normal to a flat surface with an error of the order of 1% of the diffraction limit or less. Purpose of the study. Studying of the metrological properties of the optical-information method of sub-diffraction angular measurements and their dependence on the volume of processed images, on spatial resolution, sampling error as well as the signal-to-noise ratio. Metod of investigation. Simulation of interference patterns; mock-up of the processing algorithm building; numerical and analytical solving of equations for angular deviation of the laser beam. Main results. New method for measuring the angular position of a laser beam relative to the normal to a flat surface have been proposed in the paper, which, in principle, provides an error of about 1/10–1/100 of the diffraction limit. The method is based on the specially developed algorithm for mathematical processing of an array of two-dimensional interference patterns created by a Michelson interferometer with a moving retro-reflector. This optical design does not require large longitudinal dimensions, like in the autocollimation method, and is, in principle, insensitive to vibration. The proposed method is essentially an optical information method, since its implementation requires huge calculations based on the mathematical model of the measurement process. The optical circuit and data processing algorithm are described. The results of numerical simulation of the measurement process are presented. It is shown that the algorithm works well even for highly noisy data and gives much better accuracy even with low spatial resolution of images. The effect is achieved by increasing the number of processed interference patterns and correspondingly reducing the bandwidth of the measuring system. Practical significance. The relationships obtained in the work make it possible to develop a practical implementation of a sub-diffraction angle meter and the corresponding experimental research methodology.

 this study was financially supported by the Ministry of Science and Higher Education of Russian Federation during implementation of the project “Development and research of methods for managing groups of autonomous unmanned aerial vehicles based on advanced information support systems and interaction between individual devices in the group”, № FZWF-2024-0002