Wide-range calibration of optical radiation power meters

Abstract This work is devoted to the development of a method for the quantitative comparison of the luminosity of weakly luminous samples, such as self-glowing crystals. A self-glowing crystal is an efficient scintillator, whose self-luminescence is due to the decay of a radioactive isotope introduced into the crystal matrix during its growth. Such crystals can be used as low current sources with a service life of 50 years or more. This technique takes into account the luminescence spectra of the samples under study, the spectral functions of the spectrometer and photodetector. Information on the luminescence spectra of samples can be obtained based on their cathodoluminescence spectra. Thanks to the calculations performed according to this technique, it becomes possible to estimate the optical radiation power of a self-glowing crystal, which can be converted into an electric current using a photodiode. Also, the proposed technique can be applied to assess the luminosities of any materials under the influence of radioactive radiation.

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Optical-electronic monitoring system of biomedical indicators

Фізика і хімія твердого тіла ◽

10.15330/pcss.21.4.779-784 ◽

2020 ◽

Vol 21 (4) ◽

pp. 779-784

Author(s):

G.I. Barylo ◽

M.S. Ivakh ◽

Z.M. Mykytiuk ◽

I.P. Kremer

Keyword(s):

Optical Radiation ◽

Electronic Monitoring ◽

The Internet ◽

Medical Systems ◽

Biological Objects ◽

Wide Range ◽

Signal Path ◽

Measurement Transformation ◽

The Internet Of Things ◽

Methods Of Measurement

The work is devoted to the development of medical systems for monitoring biomedical indicators. The problem of developing a universal hardware software-controlled control system for the diagnosis of biological objects is solved. The main requirements for such a system are a wide range of functionality for combining different methods of measurement transformation and compliance with modern trends in the development of microelectronic sensors. Given the requirements for modern microcircuitry, in particular for sensing devices of the Internet of Things, the signal path of the sensors is implemented on the basis of PSoC family 5LP Family Cypress. Approbation of the developed system is carried out in the course of research of the character of optical radiation in the course of measurement of biomedical indicators.

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Research of multisensor characteristics based on optical fiber

Doklady BGUIR ◽

10.35596/1729-7648-2021-19-1-70-78 ◽

2021 ◽

Vol 19 (1) ◽

pp. 70-78

Author(s):

A. O. Zenevich ◽

S. V. Zhdanovich ◽

H. V. Vasilevski ◽

A. A. Lagutik ◽

T. G. Kovalenko ◽

...

Keyword(s):

Optical Fiber ◽

Minimum Distance ◽

Optical Radiation ◽

Radiation Power ◽

Optical Loss ◽

Single Mode ◽

Optical Reflectometry ◽

Optimal Values ◽

The Impact ◽

To Receive

The research results of multisensors based on optical fiber, the principle of which is to change the conditions of propagation of optical radiation in the optical fiber in the places where macro-bends are formed at the points of impact, are presented in the paper. The formation of macro-bends leads to an additional attenuation of the power of optical radiation propagating through the optical fiber. A single-mode optical fiber was used with the parameters, which are supported by numerous manufacturers and comply with the recommendations of ITU-T G.655. The measurements were carried out for four wavelengths of optical radiation (1310, 1490, 1550, 1625 nm), corresponding to the transparency windows of the optical loss spectrum of the optical fiber. Using optical reflectometry methods, it was determined that the amount of attenuation of optical radiation of each macro-bend formed at the point of action of the multisensor does not depend on the number of simultaneously formed macro-bends and also does not depend on the location of the point of action along the length of the multisensor. The dependences of the attenuation of the optical radiation power introduced by the macro-bends of the optical fiber on the radius, length, or angle of the macro-bends formed at the multisensory impact points are determined experimentally. The obtained dependences also allow one to determine the optimal parameters of the formed macro-bends of the multisensor to obtain the maximum range of attenuation change for each value of the wavelength. The values of the minimum distance between the impact points, the maximum number of impact points and the optimal values of the radius and angle of the optical fiber macro-bend at the impact points are determined. The results obtained provide opportunities to continue the development of multisensors that allow us to receive information about parameters from several impact points, that are located on a single optical fiber, simultaneously.

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Description and Characterization of a 114-kWe High-Flux Solar Simulator

Journal of Solar Energy Engineering ◽

10.1115/1.4047295 ◽

2020 ◽

Vol 143 (1) ◽

Author(s):

Shunzhou Chu ◽

Fengwu Bai ◽

Fuliang Nie ◽

Zhifeng Wang

Keyword(s):

Conversion Efficiency ◽

Focal Plane ◽

Radiation Power ◽

Thermal Power ◽

Mapping Method ◽

Stagnation Temperature ◽

High Flux ◽

Power Module ◽

Solar Simulator ◽

Wide Range

Abstract A high-flux solar simulator is essential for evaluating solar thermal components under controlled and adjustable flux input conditions. This study presents a newly built high-flux solar simulator composed of 19 individual units. Each unit includes a xenon short-arc lamp (each consuming up to 6 kW electricity power) coupled with a truncated ellipsoidal reflector, a cooling blower, and a power module. The power module yields a current in the range of 50–160 A. The number of lamps in use is flexible, which allows for a wide range of radiation flux (10%–100%) on the focal plane. The radiation power, peak value, flux distribution on the circular target plane, and conversion efficiency are evaluated based on a flux mapping method. The results indicate that the proposed solar simulator is capable of achieving thermal power of 23.3 kW, peak flux in excess of 1.78 MW/m2, a stagnation temperature exceeding 2360 °C, and average irradiance of 773.4 kW/m2 on the focal plane (diameter of 260 mm). The electro-thermal conversion efficiency of the simulator is 35.7%. A ray-tracing method was employed, and the simulation results were found to be in good agreement with those in the experiments. An experimental test of a volumetric ceramic receiver was conducted, and the results indicate the availability and applicability of the high-flux solar simulator when carrying out studies about solar receivers.

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Depth-of-Field-Extended Plenoptic Camera Based on Tunable Multi-Focus Liquid-Crystal Microlens Array

Sensors ◽

10.3390/s20154142 ◽

2020 ◽

Vol 20 (15) ◽

pp. 4142 ◽

Cited By ~ 2

Author(s):

Mingce Chen ◽

Wenda He ◽

Dong Wei ◽

Chai Hu ◽

Jiashuo Shi ◽

...

Keyword(s):

Liquid Crystal ◽

Radiation Power ◽

Focal Length ◽

Microlens Array ◽

Oxide Semiconductor ◽

Depth Of Field ◽

Digital Refocusing ◽

Wide Range ◽

Cmos Sensor ◽

Plenoptic Camera

Plenoptic cameras have received a wide range of research interest because it can record the 4D plenoptic function or radiance including the radiation power and ray direction. One of its important applications is digital refocusing, which can obtain 2D images focused at different depths. To achieve digital refocusing in a wide range, a large depth of field (DOF) is needed, but there are fundamental optical limitations to this. In this paper, we proposed a plenoptic camera with an extended DOF by integrating a main lens, a tunable multi-focus liquid-crystal microlens array (TMF-LCMLA), and a complementary metal oxide semiconductor (CMOS) sensor together. The TMF-LCMLA was fabricated by traditional photolithography and standard microelectronic techniques, and its optical characteristics including interference patterns, focal lengths, and point spread functions (PSFs) were experimentally analyzed. Experiments demonstrated that the proposed plenoptic camera has a wider range of digital refocusing compared to the plenoptic camera based on a conventional liquid-crystal microlens array (LCMLA) with only one corresponding focal length at a certain voltage, which is equivalent to the extension of DOF. In addition, it also has a 2D/3D switchable function, which is not available with conventional plenoptic cameras.

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Research into Influence from Different Ranges of PAR Radiation on Efficiency and Biochemical Composition of Green Salad Foliage Biomass

Light & Engineering ◽

10.33383/2018-077 ◽

2018 ◽

pp. 38-47

Author(s):

Leonid B. Prikupets ◽

George V. Boos ◽

Vladislav G. Terekhov ◽

Ivan G. Tarakanov

Keyword(s):

Biochemical Composition ◽

Optical Radiation ◽

Spectral Radiation ◽

Irradiance Level ◽

Capacity Curves ◽

Radiation Action ◽

Wide Range

Results of the first photobiological studies of optimisation of LED phyto irradiators spectrum and irradiance level, when growing saladgreengrocers plants in greenhouses and plant factories in photoculture conditions, are presented in the article. The results are given as a series of producing capacity curves for salad and basil plants when irradiating by quasimonochromatic spectrum for three PAR ranges: blue, green and red. In the experiment, levels of photosynthetic photon irradiance (70 ? 230) µmol/s·m2 and of irradiance (13 ? 60) W/m2 were varied within a wide range. “Rough” spectra of optical radiation action estimated over producing capacity of plants with different irradiance levels are given, and questions of additivity of different spectral radiation influence in forming vegetable biomass are considered. Evaluations of efficiency of various PAR intervals for synthesis of biochemical combinations determining nutrition facts of the studied cultures are performed.

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Optical-radiation power limiting in high-scattering media

Doklady Physics ◽

10.1134/1.1810575 ◽

2004 ◽

Vol 49 (9) ◽

pp. 512-515

Author(s):

S. A. Tereshchenko ◽

V. M. Podgaetskii

Keyword(s):

Optical Radiation ◽

Radiation Power ◽

Scattering Media

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AMPLITUDE CHARACTERISTICS OF SILICON PHOTO-ELECTRON MULTIPLIER’S PHOTORESPORENSE

Visnyk Universytetu “Ukraina” ◽

10.36994/2707-4110-2019-1-22-03 ◽

2019 ◽

Author(s):

Maryna Asayonak ◽

Andrey Zenevich ◽

Yauhen Novikau

Keyword(s):

Optical Radiation ◽

Supply Voltage ◽

Block Diagram ◽

Wave Length ◽

Photon Counting ◽

Current Mode ◽

Average Amplitude ◽

Avalanche Photodetectors ◽

Operating Modes ◽

Wide Range

Currently, in many applications, photodetectors are needed that provide registration of optical radiation in a wide range of intensities and allow combining two operating modes: current mode and photon counting. These devices include silicon photoelectronic multipliers (SiPM), which have a number of advantages compared to electrovacuum photomultipliers and avalanche photodetectors. However, the influence on the photoresponse characteristics of SiPM of such important factors as the supply voltage and temperature has not been studied enough. The influence of these factors on the amplitude parameters of the photoresponse of SiPM is studied. The block diagram of the experimental setup is presented, with the help of which the photoresponse characteristics of SiPM with n+-n-p+ and p+-p-n+ structures manufactured by Integral OJSC (Republic of Belarus) were measured. The dependences of the average amplitude of the photoresponse on the supply voltage and temperature of silicon photomultipliers for various wave-lengths of optical radiation are presented. It was found that when SiPM were exposed to optical pulses with the same duration and energy exposure at the same temperature at the same overvoltage, the photoresponse amplitude was larger for a SiPMr with p+-p-n+ structure regardless of the wave-length of optical radiation. It was found that, when the overvoltage changes, the increase in the photoresponse amplitude is observed only in the overvoltage range ΔU = 0 ¸ 3 V for all the studied SiPM, irrespective of the wave-length of the detected optical radiation and temperature. It was determined that a decrease in temperature led to an increase in the amplitude of the photoresponse pulses. The temperature dependence of the amplitude of the photoresponse was most pronounced for SiPM with the p+-p-n+ structure. It was shown that the dependences of the average amplitude of the photomonitor Si-PM on the energy exposure have a linear section, the length of which depends on the wavelength of the detected optical radiation.

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