Calibration simulation for stereoscopic optical systems using optical design software

To reconstruct three-dimensional (3D) structure of objects and measure their geometric parameters using stereoscopic imaging systems, it is necessary to implement a number of image processing algorithms. For higher system efficiency, the choice of these algorithms and mathematical models should be taken into account at the stage of optical system design. We demonstrate the capabilities of optical design software to perform computer simulation of geometrical calibration for stereoscopic systems. The simulation allows comparison of mathematical models used for 3D reconstruction and estimation of 3D measurements errors caused by tolerances of optical elements, temperature variations and other factors. Using this technique, we analyze the design of prism-based stereoscopic system and show that the proposed ray tracing camera model considering pupil aberrations provides higher measurement precision. The results of computer simulation are confirmed by experiments with the self-developed stereoscopic system

Multi-spectral image processing for the measurement of a spatial temperature distribution on the surface of a laser-heated microscopic object

In this paper, we demonstrate that combining a laser heating (LH) system with a tandem acousto-optical tunable filter (TAOTF) allows us to measure the temperature distribution (TD) across a laser-heated microscopic specimen. Spectral image processing is based on one-dimensional (1D) non-linear least squares fitting of the Planck radiation function. It is applied for determining the temperature T at each point (x, y) of the specimen surface. It is shown that spectral image processing using the 1D non-linear least squares fitting allows measurement of the TD of the laser-heated microscopic specimen with higher precision and stability than those of the conventional linear least-squares fitting of the Wien approximation of Planck’s law.The Russian Science Foundation (project #17-12-01535) financially supported the work

Resistance investigation of diamond-like carbon coatings to cyclic temperature changes

Optical elements used in outer space must be designed considering the effects of such factors as space vacuum, atomic oxygen in low Earth orbit, solar and space radiation, large temperature drops, gas release of spacecraft materials and structural elements, space dust and debris. In order to harden and protect mirror surfaces of optical elements from external factors, it has been promisingly applied diamond-like carbon coatings on their surface. These coatings are characterized by high strength and wear-resistant properties, in particular, high hardness, low friction coefficient, high wear resistance and chemical inertness. This leads to their widespread use in various fields of science and technology, including optical instrumentation. This paper presents the results of testing an aluminum mirror with a diamond-like carbon coating under the effect of cyclic temperature changes for determining their ability to withstand a rapid cyclic ambient temperature change, and specifically, to maintain optical and mechanical properties. © 2021 Institute of Physics Publishing. All rights reserved