Matrix Photodetector Research Articles

Algorithm for Estimating the Laser Beam, Matrix Photo Receiver on the Background of the Gaussian Noise Using Full Sufficient Statistics of the Received Scattered Radiation

An algorithm for estimating the position of the laser beam by the component scattered in the atmosphere by a matrix photodetector against a background of Gaussian noise is developed. The algorithm is based on the Lehman-Scheffe theorem, which allows one to obtain effective estimates of the distribution parameters using complete sufficient statistics for reports of the observed implementation of scattered laser radiation. The obtained estimates provide the best quality of parameter estimation for any finite sample sizes and do not require additional studies

Dependence of the Spatial Resolution of a Matrix Photodetector Based on Indium Antimonide on the Thickness of the Photosensitive Layer

The photoelectric interconnection of matrix photodetectors in the medium-wave IR range of 320 × 256 elements with a step of 30 μm and 640 × 512 elements with a step of 15 μm based on indium antimonide is investigated. The dependence of the crosstalk value on the thickness of a thinned InSb bulk structure was determined. The interrelation of the elements of matrix photodetectors based on epitaxial indium antimonide is significantly less than the interrelation based on bulk indium antimonide.

Analysis of changes in the detection range of radiation by photodetector when using a matrix photodetector

Analysis of changes in the detection range of radiation by photodetector when using a matrix photodetector

Analysis of changes in the detection range of radiation by a photodetector when using a matrix photodetector

Analysis of changes in the detection range of radiation by a photodetector when using a matrix photodetector

Evaluation And Selection Of Colour Spaces For Digital Systems

The research examined the changing of colour difference by the control colours depending on the choice of colour space when working with matrix photo detector. The spectral characteristics of photo detectors from different manufacturers noticeably differ from each other and from the addition the difference in colour quality between different digital devices. A software method for studying the colour rendition of the image obtained by digital devices based on the selection of an individual colour space for each matrix photo detector is proposed. To analyze and evaluate the capabilities of the spectral characteristics of matrix photo detectors, the control colour method based on the Mansell Atlas was used. The analysis of the obtained parameters of 14 colours was carried out according to various criteria for seven colour spaces: sRGB, AdobeRGB, DCI-P3 RGB, M1N1P1, PAL / SECAM, Wide Gamut RGB, ProPhoto RGB. Also studied the influence of the choice of colour space on the change in the coordinates of the source 6,500 K. Based on the colour differences of the control colours, it is possible to choose the optimal colour space for working with a specific matrix photo detector. The latter will reduce colour distortion at the initial stage of image registration. The ways for improving the colorimetric method of control colours are proposed as applied to digital devices at the software level.

Multispectral matrix silicon photodetectors with the IR range registration

The paper presents a multi-layer digital camera matrix photodetectors modifications. Modifications are a matrix photodetectors two main types hybrid: spatial structure and multilayer. The matrix photodetectors issue current state with the registering images function in both the visible and IR range is considered in detail. Such well-known manufacturers photo matrices analysis is carried out. To obtain a multispectral image, it is proposed to introduce light-sensitive layers for the near and mid-IR ranges. The developed matrices patterns are presented that allow achieving a balance of each of the five channels (red, green, blue, near and mid-IR) so that the spectrum each selected range has the matrix surface equal share. A layers’ combination is also proposed that allows to apply them separately-a layer that will minimize the noise in this area and focus on the infrared region, and use the visible one as an auxiliary one. At the same time, to get a full-fledged image, you need to apply each pixel interpolation. The light-sensitive layers’ distribution principle in each pattern is described.

Application of a Warm Aperture Diaphragm in Cooled Small-Format Matrix Photodetectors

The designs of a warm (uncooled) aperture diaphragm in a gas-filled cryostat with a matrix photodetector sensitive in the infrared spectral range are studied numerically and experimentally. It is shown that for the chosen design of a warm aperture diaphragm, a $$384\times 288$$ pixel matrix photodetector is cooled by liquid nitrogen to operating temperatures (85 K) in less than 40 seconds, and by a throttle microcooler in 15 seconds, while maintaining the standard sensitivity of photodetectors based on cadmium–mercury–tellurium (CMT) structures.

Spatial-frequency characteristics of photo matrices for colour image

The paper presents a spatial-frequency characteristics comparative analysis for obtaining a colour’s image several methods. The modern colour image matrix spatial-frequency characteristics photodetectors spatial-frequency characteristics are presented. Both unique and advanced matrix photodetectors of both multilayer type and standard systems with mosaic filters are being investigated. The author’s matrix photodetector input signal distortion estimation, where two-layer sensors are presented, is carried out. Spatial-frequency characteristics comparative analysis showed that three-matrix colour image systems provide the best spatial resolution and the highest spatial (contrast) sensitivity than mosaic-type photodetectors.

An Apparatus for Measuring the Characteristics of the High-Speed Image Converter Cameras Operating in the Range of Soft X-Rays and Vacuum UV

A pumped vacuum apparatus is described that contains an electron gun with an adjustable high-voltage voltage source, interchangeable metal targets, and flanges to which the object under study is connected. The apparatus is especially designed to measure the spatial and temporal characteristics of high-speed image converter streak cameras that operate in the soft X-ray range. It can be used for research and measurements in the design of soft X-ray photodetectors and their main parts, for example, microprobe detectors, imaging devices, solid-state linear and matrix photodetectors, photoemitters operating in vacuum, etc.

The Use of Raman Spectroscopy for the Rapid Analysis of Chemical Compounds

The use of Raman spectroscopy for the rapid analysis of chemical substances is considered. To reduce the time of the analysis, it is proposed to use a Fourier-transform spectrometer based on a static Michelson interferometer, in which a spatial scan of the interferogram occurs. Two schemes of implementation of a model of a static Fourier-transform spectrometer are represented: with a matrix photodetector device (PD) that makes it possible to obtain better spectral resolution and with a linear PD, which is more sensitive. The Raman spectra are recorded in the spectral range of 800 to 1050 nm, which makes it possible to perform the analysis in the daytime. A laser with wavelength λ = 785 nm and power of 1.5 W is used as the source of excitation radiation. The interferograms obtained on both models of Fourier-transform spectrometers are presented; the Raman spectra of the following test substances are restored: 1,4-bis(5-phenyl-2-oxazolyl)benzene (POPOP, C24H16N2O2), stilbene (C14H12), chloroform (CHCl3), and ethanol (C2H5OH), and their correlation matrices are presented.

Diffraction model of a laser speckle interferometer for measuring micro-displacements of objects with scattering surface

On the basis of diffraction transformations of an optical wave field a mathematical model for the formation of speckle modulated interference patterns and signals at the output of a speckle interferometer is developed, which allows us to identify their properties and quantitative parameters. Speckle interferometers based on a Michelson arrangement are considered, where objects with scattering surfaces are used instead of mirrors in the reference and object arms. Results of numerical simulation of speckle modulated interference patterns on the basis of diffraction transformations of wave fields in an interferometer are discussed. Simulated images obtained at the output of the interferometer when focusing laser beams on the scattering surfaces of the controlled and reference objects are considered. Experimental results of using a speckle interferometer with a digital matrix photodetector for measuring the temperature micro-displacements of an object with a scattering surface and a quantitative comparison of experimental data with the results obtained by a numerical experiment using a diffraction model of a speckle interferometer are presented.

Matched Filtering of Small-Sized Objects in Images Containing Constant Spatial Interference

The influence of spatial inhomogeneity of the photoelectric characteristics of a matrix photodetector (PDD) on the quality of detection of small-sized objects in the image formed by it is considered. It is shown that in the conditions of spatially inhomogeneous natural noise of the PDD, the traditionally applied two-point correction is not optimal for subsequent matched image filtering performed in order to increase the reliability of object detection. A two-stage algorithm for constructing a linear spatially invariant matched filter is proposed, which provides a significant increase in the reliability of detecting weak small-sized objects against the background of uncorrelated noise in images containing interference due to the spatial heterogeneity of the PDD characteristics.

HgCdTe-Based 640 × 512 Matrix Midwave Infrared Photodetector

Matrix photosensitive elements based on a HgCdTe semiconductor solid solution on silicon substrates with 640 × 512 elements at a pitch of 25 μm with a long-wavelength sensitivity of 5 μm at half maximum are designed and produced. The scheme and topology are developed according to which matrix multiplexers with 640 × 512 elements at a pitch of 25 μm, which ensure operating modes at a clock frequency up to 10 MHz, are manufactured. Using a hybrid assembly method on indium bumps, a matrix photodetector with 640 × 512 elements at a pitch of 25 μm is produced. The best photodetector specimens are characterized by the following parameters: average NETD value 99.5%.

Modeling of image formation with a space-borne Offner hyperspectrometer

In this paper, we developed a mathematical model of image formation that allows a predictive hyperspectral image to be generated. The model takes into account the formation of an optical image using a matrix photodetector. The paper presents a numerical modeling of hyperspectral image formation and gives estimates of spatial and spectral resolution, as well as analyzing the adequacy of the results.

Development of an algorithm for calculating the energy concentration of infrared optical systems, taking into account the effect of the charge flow effect on a matrix photodetector

Development of an algorithm for calculating the energy concentration of infrared optical systems, taking into account the effect of the charge flow effect on a matrix photodetector

Влияние радиации на ключевые параметры матричных фотоприёмных устройств

Влияние радиации на ключевые параметры матричных фотоприёмных устройств

Simulation of Laser Radiation Interaction with InSb Matrix Photodetector in the Software Package Logos

The article is devoted to simulation of the formation and evolution of the temperature field in an InSb matrix photodetector upon exposure of a part of its surface to intense laser radiation. A simulation model has been developed in software package LOGOS that allows the evolution of the temperature field to be predicted. The simulation model is described, and the results of numerical experiments are presented.

Back-Side Electron-Bombarded Silicon pin-Strip

Introduction. In recent decades, in the field of photoelectronics, special attention has been paid to the development of semiconductor matrix photodetectors. These detectors have become an effective alternative to existing television receiving systems. Among such devices, linear position-sensitive sensors are used in cases where the rapid registration of changes to the environment is required (for instance, high-speed locators for flying vehicles).Aim. To develop a strip of silicon pin-diodes as part of a hybrid IR-detector for effective registration of photoelectrons with time resolution less than 10 ns, as well as to model the key electro-physical characteristics of the strip.Materials and methods. In the device under development, the registration of photoelectrons is achieved by the presence of a near-surface field using p ++–p junction formed by diffusion of boron into the silicon with resistivity of 3 kΩ · cm. The pulling field is also formed in the space charge region between p ++ - and n ++ -regions. Diffusion of phosphorus was carried out to create the n ++ -region. Numerical calculations of potential distribution, concentration of free charge carriers and currents were carried out using software for 1D- and 2D-modelling (SimWin and TCAD Synopsys).Results. 2D-calculation of charge carrier concentration and potential distribution was performed. The study determined the minimum bias for the complete depletion of the i-layer, including that for longitudinal grooves of various depths. The strip was tested as part of a hybrid photoelectric device by irradiating light pulses from IR LED. When the voltage on the diodes was reached –270 V, the duration of the signal front on all channels was 5…9 ns.Conclusion. For use in IR-hybrid detectors, a strip of 12 silicon pin-diodes was developed with a sensitive element of 24 × 0.2 mm in dimension. The study of pulse characteristics showed that the necessary duration of the front signal on all channels was achieved without thinning thus satisfying the requirements for high-speed position-sensitive sensor of the infrared radiation.

Methods of spatial and temporal processing of images in optoelectronic control systems

The data about the effect of image quality on accuracy of information parameters are presented. Studies on accuracy of measuring characteristics of objects in their images depending on image quality are described. Studies showed that accuracy of measurement algorithms improves with an increase in sample sizes of frames in the optoelectronic system (OES). Image quality is improved by processing the frame samples with algorithms for increasing resolution and reducing noise levels, both in single-point and multi-position OESs based on digital cameras with matrix photodetectors. The maximum effect of an increase in information content of the image and accuracy of measuring algorithms is determined by variations in the pixel structure of each image in the region of brightness gradient boundaries. In the single-point OESs which ensure high quality of optical images without noise factors and variations of other external parameters, the optimal number of frames in the OES is four.

A Megapixel Matrix Photodetector of the Middle Infrared Range

Abstract—The characteristics of MWIRs focal plane aeeays made in the form of a hybrid chip based on a planar n+–p-HgCdTe focal matrix with 2048 × 2048 elements and a silicon multiplexer are considered. The temperature dependence of the reverse current of elements in the 125–300 K range had a characteristic Arrhenius dependence with an activation energy close to the band gap of the semiconductor and was limited by the diffusion component of the current. At a lower temperature, the current was limited by the generation of carriers with the participation of a deep level near the middle of the forbidden band. The histogram of the detectability of the elements of the matrix had the form of a symmetric curve with a maximum and an average value ≈ 1.3 × 1012 cm Hz1/2/W.