The paper presents an analysis of designing an optical-electronic imaging system designed to operate in a turbulent atmosphere. The optoelectronic system design is based on hill-climbing and phase conjugation technique using a bimorph adaptive mirror and a Shack-Hartmann-type wavefront sensor. The system corrects the wavefront distortion of the laser radiation passing through the test object and an inhomogeneous medium that simulates a turbulent atmosphere. Criteria for restoring the geometric characteristics of the test object are analyzed using the proposed hybrid algorithm, including spatial-frequency analysis of the recorded spectrum.
A high-quality flat wavefront is usually used to calibrate the Shack-Hartmann wavefront sensors. The article discusses the possibility of calibrating sensors with spherical wavefronts. Special attention is paid to the consideration of calibration in standard laboratory conditions. The mathematical apparatus and the scheme of the experiment are considered. A statistical analysis of the calibration accuracy of the Shack-Hartmann wavefront sensor is carried out. Spherical wavefronts from a point source were used as references. As a result, the parameters of the wavefront sensor were determined: the focal length and the dimensions of the digital camera pixel. This calibration method is considered in comparison with the traditional calibration using flat wavefronts.
In this work, the task was to investigate the properties of niobium oxide layers (geometric thickness, their optical constants n and k) in the design of a multilayer interference filter, in the manufacture of which a system for indirect control of the thickness of the deposited films is used. As an indirect control system, we used both quartz control and optical broadband control. The experiment was based on using a 6-position changer, which makes it possible to change the substrate on which the coating is deposited during the process of making a light filter by the electron beam evaporation. Thanks to this, we obtained substrates with a niobium oxide film, which corresponded to 1, 9, 17, 25 and 31 layers of an interference filter. Analysis of the obtained samples allows us to determine the geometric layer thickness, refractive index and absorption and to evaluate the effect of a change in the solid angle of the flow of the evaporated substance due to a change in the amount of substance in the crucible on the thickness of the sprayed film on the substrate, when we use indirect methods of thickness control. We used Ferrotec EV M-10 electron beam guns to evaporate the construction materials of the interference filter. For the evaporation of SiO2, a stock stream crucible was used; for the evaporation of Nb2O5, we ourselves made a special crucible in order to optimize the evaporation mode of this material. We managed to optimize the power of the electron beam and at the same time to obtain the desired form of the flow of the evaporated substance. Analysis of the obtained samples made it possible to answer the question of whether physicochemical changes in niobium oxide in the crucible occur when exposed to an electron beam for a sufficiently long time. In the course of the research, an X-ray phase analysis of the Nb2O5 film-forming material from various manufacturers was carried out.
KEYWORDS: Control systems, Optical filters, Glasses, Optical coatings, Monochromators, Optical amplifiers, Control systems design, Thin film coatings, Fabry–Perot interferometers, Quartz
The principle of construction and design of the optical control system of the thickness of thin-film interference coatings applied in vacuum with the low-cost realization has been developed. The optical control system is built on the principle of measurement directly on the product - direct control at one wavelength (monochromatic). Model, allowing to evaluate technical capabilities of introduced system was made.
A high-quality flat wave front is usually used to calibrate the Shach-Hartmann wave-front sensors. The article discusses the possibility of calibrating sensors with spherical wave fronts. Special attention is paid to the consideration of calibration in standard laboratory conditions. The mathematical apparatus and the scheme of the experiment are considered.
In this paper we consider two approaches widely used in testing of spherical optical surfaces: Fizeau interferometer and Shack-Hartmann wavefront sensor. Fizeau interferometer that is widely used in optical testing can be transformed to a device using Shack-Hartmann wavefront sensor, the alternative technique to check spherical optical components. We call this device Hartmannometer, and compare its features to those of Fizeau interferometer.
In this paper we consider two approaches widely used in testing of wide aperture optics: Fizeau interferometer and Shack-Hartmann wavefront sensor. Fizeau interferometer that is common instrument in optical testing can be transformed to a device using Shack-Hartmann wavefront sensor, the alternative technique to check wide aperture optical components. We call this device Hartmannometer, and compare its features to those of Fizeau interferometer.
In this paper we consider two approaches widely used in optical testing: Shack-Hartmann wavefront sensor and Fizeau
interferometer technique. Fizeau interferometer that is widely used in optical testing can be easily transformed to a device
using Shack-Hartmann wavefront sensor, the alternative technique to check optical components. We call this device
Hartmannometer, and compare its features to those of Fizeau interferometer.
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