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Articles de revues sur le sujet « Photon counting »

Auteur : Grafiati
Publié le 4 juin 2021
Mis à jour le 16 novembre 2024

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1

Reutov, Aleksei, et Denis Sych. « Photon counting statistics with imperfect detectors ». Journal of Physics : Conference Series 2086, no 1 (1 décembre 2021) : 012096. http://dx.doi.org/10.1088/1742-6596/2086/1/012096.

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Abstract Measurement of photon statistics is an important tool for the verification of quantum properties of light. Due to the various imperfections of real single photon detectors, the observed statistics of photon counts deviates from the underlying statistics of photons. Here we analyze statistical properties of coherent states, and investigate a connection between Poissonian distribution of photons and sub-Poissonian distribution of photon counts due to the detector dead-time corrections. We derive a functional dependence between the mean number of photons and the mean number of photon counts, as well as connection between higher-order statistical moments, for the pulsed or continuous wave coherent light sources, and confirm the results by numerical simulations.
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Jang, Jae-Young, et Myungjin Cho. « Lensless Three-Dimensional Imaging under Photon-Starved Conditions ». Sensors 23, no 4 (20 février 2023) : 2336. http://dx.doi.org/10.3390/s23042336.

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In this paper, we propose a lensless three-dimensional (3D) imaging under photon-starved conditions using diffraction grating and computational photon counting method. In conventional 3D imaging with and without the lens, 3D visualization of objects under photon-starved conditions may be difficult due to lack of photons. To solve this problem, our proposed method uses diffraction grating imaging as lensless 3D imaging and computational photon counting method for 3D visualization of objects under these conditions. In addition, to improve the visual quality of 3D images under severely photon-starved conditions, in this paper, multiple observation photon counting method with advanced statistical estimation such as Bayesian estimation is proposed. Multiple observation photon counting method can estimate the more accurate 3D images by remedying the random errors of photon occurrence because it can increase the samples of photons. To prove the ability of our proposed method, we implement the optical experiments and calculate the peak sidelobe ratio as the performance metric.
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Pile, David. « Photon counting ». Nature Photonics 6, no 1 (22 décembre 2011) : 4. http://dx.doi.org/10.1038/nphoton.2011.340.

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Hu, Huiqin, Xinyi Ren, Zhaoyang Wen, Xingtong Li, Yan Liang, Ming Yan et E. Wu. « Single-Pixel Photon-Counting Imaging Based on Dual-Comb Interferometry ». Nanomaterials 11, no 6 (24 mai 2021) : 1379. http://dx.doi.org/10.3390/nano11061379.

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We propose and experimentally demonstrate single-pixel photon counting imaging based on dual-comb interferometry at 1550 nm. Different from traditional dual-comb imaging, this approach enables imaging at the photon-counting regime by using single-photon detectors combined with a time-correlated single-photon counter to record the returning photons. The illumination power is as low as 14 pW, corresponding to 2.2 × 10−3 photons/pulse. The lateral resolution is about 50 μm. This technique paves the way for applying dual-comb in remote sensing and imaging.
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Yeo, Gilsu, et Myungjin Cho. « Three-Dimensional Digital Zooming of Integral Imaging under Photon-Starved Conditions ». Sensors 23, no 5 (28 février 2023) : 2645. http://dx.doi.org/10.3390/s23052645.

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In this paper, we propose new three-dimensional (3D) visualization of objects at long distance under photon-starved conditions. In conventional three-dimensional image visualization techniques, the visual quality of three-dimensional images may be degraded because object images at long distances may have low resolution. Thus, in our proposed method, we utilize digital zooming, which can crop and interpolate the region of interest from the image to improve the visual quality of three-dimensional images at long distances. Under photon-starved conditions, three-dimensional images at long distances may not be visualized due to the lack of the number of photons. Photon counting integral imaging can be used to solve this problem, but objects at long distance may still have a small number of photons. In our method, a three-dimensional image can be reconstructed, since photon counting integral imaging with digital zooming is used. In addition, to estimate a more accurate three-dimensional image at long distance under photon-starved conditions, in this paper, multiple observation photon counting integral imaging (i.e., N observation photon counting integral imaging) is used. To show the feasibility of our proposed method, we implement the optical experiments and calculate performance metrics, such as peak sidelobe ratio. Therefore, our method can improve the visualization of three-dimensional objects at long distances under photon-starved conditions.
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Ma, Rujia, Wei Kong, Tao Chen, Rong Shu et Genghua Huang. « KNN Based Denoising Algorithm for Photon-Counting LiDAR : Numerical Simulation and Parameter Optimization Design ». Remote Sensing 14, no 24 (9 décembre 2022) : 6236. http://dx.doi.org/10.3390/rs14246236.

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Photon-counting LiDAR can obtain long-distance, high-precision target3D geographic information, but extracting high-precision signal photons from background noise photons is the key premise of photon-counting LiDAR data processing and application. This study proposes an adaptive noise filtering algorithm that adjusts parameters according to the background photon count rate and removes noise photons based on the local mean Euclidean distance. A simulated photon library that provides different background photon count rates and detection probabilities was constructed. It was then used to fit the distribution relationship between the background photon count rate and the average KNN (K-Nearest Neighbor) distance (k = 2–6) and to obtain the optimal denoising threshold under different background photon count rates. Finally, the proposed method was evaluated by comparing it with the modified density-based spatial clustering (mDBSCAN) and local distance-based statistical methods. The experimental results show that various methods are similar when the background noise rate is high. However, at most non-extreme background photon count rate levels, the F of this algorithm was maintained between 0.97–0.99, which is an improvement over other classical algorithms. The new strategy eliminated the artificial introduction of errors. Due to its low error rates, the proposed method can be widely applied in photon-counting LiDAR signal extraction under various conditions.
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Kim, Hyun-Woo, Min-Chul Lee et Myungjin Cho. « Three-Dimensional Image Visualization under Photon-Starved Conditions Using N Observations and Statistical Estimation ». Sensors 24, no 6 (7 mars 2024) : 1731. http://dx.doi.org/10.3390/s24061731.

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In this paper, we propose a method for the three-dimensional (3D) image visualization of objects under photon-starved conditions using multiple observations and statistical estimation. To visualize 3D objects under these conditions, photon counting integral imaging was used, which can extract photons from 3D objects using the Poisson random process. However, this process may not reconstruct 3D images under severely photon-starved conditions due to a lack of photons. Therefore, to solve this problem, in this paper, we propose N-observation photon-counting integral imaging with statistical estimation. Since photons are extracted randomly using the Poisson distribution, increasing the samples of photons can improve the accuracy of photon extraction. In addition, by using a statistical estimation method, such as maximum likelihood estimation, 3D images can be reconstructed. To prove our proposed method, we implemented the optical experiment and calculated its performance metrics, which included the peak signal-to-noise ratio (PSNR), structural similarity (SSIM), peak-to-correlation energy (PCE), and the peak sidelobe ratio (PSR).
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8

Hadfield, Robert H. « Superfast photon counting ». Nature Photonics 14, no 4 (27 mars 2020) : 201–2. http://dx.doi.org/10.1038/s41566-020-0614-0.

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9

Graydon, Oliver. « Practical photon counting ». Nature Photonics 11, no 11 (31 octobre 2017) : 684. http://dx.doi.org/10.1038/s41566-017-0042-y.

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10

Candy, B. H. « Photon counting circuits ». Review of Scientific Instruments 56, no 2 (février 1985) : 194–200. http://dx.doi.org/10.1063/1.1138328.

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Savage, Neil. « Single-photon counting ». Nature Photonics 3, no 12 (décembre 2009) : 738–39. http://dx.doi.org/10.1038/nphoton.2009.232.

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Mannil, Manoj, Tilman Hickethier, Jochen von Spiczak, Matthias Baer, André Henning, Madeleine Hertel, Bernhard Schmidt, Thomas Flohr, David Maintz et Hatem Alkadhi. « Photon-Counting CT ». Investigative Radiology 53, no 3 (mars 2018) : 143–49. http://dx.doi.org/10.1097/rli.0000000000000420.

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Pfenning, Andreas, Sebastian Krüger, Fauzia Jabeen, Lukas Worschech, Fabian Hartmann et Sven Höfling. « Single-Photon Counting with Semiconductor Resonant Tunneling Devices ». Nanomaterials 12, no 14 (9 juillet 2022) : 2358. http://dx.doi.org/10.3390/nano12142358.

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Optical quantum information science and technologies require the capability to generate, control, and detect single or multiple quanta of light. The need to detect individual photons has motivated the development of a variety of novel and refined single-photon detectors (SPDs) with enhanced detector performance. Superconducting nanowire single-photon detectors (SNSPDs) and single-photon avalanche diodes (SPADs) are the top-performer in this field, but alternative promising and innovative devices are emerging. In this review article, we discuss the current state-of-the-art of one such alternative device capable of single-photon counting: the resonant tunneling diode (RTD) single-photon detector. Due to their peculiar photodetection mechanism and current-voltage characteristic with a region of negative differential conductance, RTD single-photon detectors provide, theoretically, several advantages over conventional SPDs, such as an inherently deadtime-free photon-number resolution at elevated temperatures, while offering low dark counts, a low timing jitter, and multiple photon detection modes. This review article brings together our previous studies and current experimental results. We focus on the current limitations of RTD-SPDs and provide detailed design and parameter variations to be potentially employed in next-generation RTD-SPD to improve the figure of merits of these alternative single-photon counting devices. The single-photon detection capability of RTDs without quantum dots is shown.
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14

Shashurin, D. A., E. V. Suslova, V. A. Rozhkov, R. V. Sotenskiy, O. S. Medvedev et G. A. Shelkov. « Gd2O3–Carbon Nanoflakes (CNFs) as Contrast Agents for Photon-Counting Computed Tomography (PCCT) ». Журнал прикладной химии, no 4 (15 décembre 2023) : 337–44. http://dx.doi.org/10.31857/s0044461823040023.

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2–3 nm Gd2O3 nanoparticles deposited on carbon nanoflakes were prepared. These are new contrast agents for photon-counting computed tomography based on detectors allowing counting of separate photons. Contrast agents of the Gd2O3@C core–shell structure were prepared by graphitization of the surface of these particles. The Gd2O3 and Gd2O3@C nanoparticles obtained, aqueous solution of Gd(NO3)3·6H2O, and a dispersion of 300–500 nm Gd2O3 particles in gelatin were studied by photon-counting computed tomography. At equal gadolinium concentrations, the highest X-ray absorption was noted for Gd(NO3)3·6H2O and Gd2O3, which is associated with higher density of these samples. Carbon in the contrast agents does not affect the absorption. An algorithm was developed for semiquantitative determination of gadolinium by photon-counting computed tomography.
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15

Yang, Haodong, Qiurong Yan, Ming Wang, Yuhao Wang, Peng Li et Wei Wang. « Synchronous Clock Recovery of Photon-Counting Underwater Optical Wireless Communication Based on Deep Learning ». Photonics 9, no 11 (21 novembre 2022) : 884. http://dx.doi.org/10.3390/photonics9110884.

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In photon-counting underwater optical wireless communication (UOWC), the recovery of the time slot synchronous clock is extremely important, and it is the basis of symbol synchronization and frame synchronization. We have previously proposed a time slot synchronous clock extraction method based on single photon pulse counting, but the accuracy needs to be further improved. Deep learning is very effective for feature extraction; synchronous information is already implicit in the discrete single photon pulse signal output by single photon avalanche diode (SPAD), which is used as a communication receiver. Aiming at this characteristic, a method of time slot synchronous clock recovery for photon-counting UOWC based on deep learning is proposed in this paper. Based on the establishment of the underwater channel model and SPAD receiver model, the Monte Carlo method is used to generate discrete single photon pulse sequences carrying synchronous information, which are used as training data. Two neural network models based on regression problem and classification problem are designed to predict the phase value of the time slot synchronous clock. Experimental results show that when the average number of photons per time slot is eight, photon-counting UOWC with a data rate of 1Mbps and a bit error rate (BER) of 5.35 × 10−4 can be achieved.
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Jiang, Zhongzhi, et Qiliang Ni. « A Photon Imaging Detector Model with High Resolution and High Counting Rate ». Applied Sciences 13, no 9 (8 mai 2023) : 5798. http://dx.doi.org/10.3390/app13095798.

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A cross strip (XS) anode detector is a photon-counting imaging detector with high spatial resolution. However, due to the Poisson distribution characteristics of the photons emitted by the target, photons with a small time interval will cause signal superposition and resolution degradation. This is particularly significant at a high photon count rate. The key link that restricts the counting rate of the XS detector is the electronic system. In this paper, we propose a new electronic signal processing system scheme using a digital trapezoidal shaping filter instead of a traditional Gaussian shaping filter, which enables the detector to maintain a high resolution at high count rates. In order to verify the feasibility of the scheme, the relationship between shaping errors and shaping parameters is studied. Furthermore, the relationship between spatial resolution and photon-counting rate at different noise levels is revealed by numerical simulation. The results show that the detector can achieve a spatial resolution of <50 μm at a photon count rate of >6 MHz for 1000 e RMS noise.
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Pickford Scienti, Oliver L. P. Pickford, et Dimitra G. Darambara. « Demonstrating a Novel, Hidden Source of Spectral Distortion in X-ray Photon Counting Detectors and Assessing Novel Trigger Schemes Proposed to Avoid It ». Sensors 23, no 9 (1 mai 2023) : 4445. http://dx.doi.org/10.3390/s23094445.

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X-ray photon counting spectral imaging (x-CSI) determines a detected photon’s energy by comparing the charge it induces with several thresholds, counting how many times each is crossed (the standard method, STD). This paper is the first to demonstrate that this approach can unexpectedly delete counts from the recorded energy spectrum under some clinically relevant conditions: a process we call negative counting. Four alternative counting schemes are proposed and simulated for a wide range of sensor geometries (pixel pitch 100–600 µm, sensor thickness 1–3 mm), number of thresholds (3, 5, 8, 24 and 130) and medically relevant X-ray fluxes (106–109 photons mm−2 s−1). Spectral efficiency and counting efficiency are calculated for each simulation. Performance gains are explained mechanistically and correlated well with the improved suppression of “negative counting”. The best performing scheme (Shift Register, SR) entirely eliminates negative counting, remaining close to an ideal scheme at fluxes of up to 108 photons mm−2 s−1. At the highest fluxes considered, the deviation from ideal behaviour is reduced by 2/3 in SR compared with STD. The results have significant implications both for generally improving spectral fidelity and as a possible path toward the 109 photons mm−2 s−1 goal in photon-counting CT.
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18

Huang, Bo, Thomas D. Perroud et Richard N. Zare. « Photon Counting Histogram : One-Photon Excitation ». ChemPhysChem 5, no 10 (18 octobre 2004) : 1523–31. http://dx.doi.org/10.1002/cphc.200400176.

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Meloni, Antonella, Francesca Frijia, Daniele Panetta, Giulia Degiorgi, Carmelo De Gori, Erica Maffei, Alberto Clemente, Vincenzo Positano et Filippo Cademartiri. « Photon-Counting Computed Tomography (PCCT) : Technical Background and Cardio-Vascular Applications ». Diagnostics 13, no 4 (9 février 2023) : 645. http://dx.doi.org/10.3390/diagnostics13040645.

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Photon-counting computed tomography (PCCT) is a new advanced imaging technique that is going to transform the standard clinical use of computed tomography (CT) imaging. Photon-counting detectors resolve the number of photons and the incident X-ray energy spectrum into multiple energy bins. Compared with conventional CT technology, PCCT offers the advantages of improved spatial and contrast resolution, reduction of image noise and artifacts, reduced radiation exposure, and multi-energy/multi-parametric imaging based on the atomic properties of tissues, with the consequent possibility to use different contrast agents and improve quantitative imaging. This narrative review first briefly describes the technical principles and the benefits of photon-counting CT and then provides a synthetic outline of the current literature on its use for vascular imaging.
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Hofmann, K. H. « Photon-counting speckle imaging : the photon-counting hole in triple correlation ». Journal of the Optical Society of America A 10, no 2 (1 février 1993) : 329. http://dx.doi.org/10.1364/josaa.10.000329.

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Zhang, Hanfu, Jie Liu, Qichang An et Jianli Wang. « Time Coding-Based Single-Photon-Counting Lidar for Obtaining Spatial Location ». Photonics 10, no 4 (15 avril 2023) : 457. http://dx.doi.org/10.3390/photonics10040457.

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This paper proposes a single-photon-counting lidar based on time coding that can obtain the target’s spatial location and measure the distance and azimuth angle in real time without needing a scanning device. Multiple optical fibers were used to introduce laser echo photons into a single-pixel single-photon detector. According to the deviation in the detection time of the echo photons passing through different optical fibers, multiple distances can be obtained simultaneously. Combining the measured distances with the fiber spacing allows the calculation of the distance, azimuth angle, and spatial coordinates of the target. This lidar has the advantages of high photon detection efficiency, short signal acquisition time, and low cost compared to array detectors.
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Wang, Xiaofang, Tongyi Zhang, Yan Kang, Weiwei Li et Jintao Liang. « High-Flux Fast Photon-Counting 3D Imaging Based on Empirical Depth Error Correction ». Photonics 10, no 12 (25 novembre 2023) : 1304. http://dx.doi.org/10.3390/photonics10121304.

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The time-correlated single-photon-counting (TCSPC) three-dimensional (3D) imaging lidar system has broad application prospects in the field of low-light 3D imaging because of its single-photon detection sensitivity and picoseconds temporal resolution. However, conventional TCSPC systems always limit the echo photon flux to an ultra-low level to obtain high-accuracy depth images, thus needing to spend amounts of acquisition time to accumulate sufficient photon detection events to form a reliable histogram. When the echo photon flux is increased to medium or even high, the data acquisition time can be shortened, but the photon pile-up effect can seriously distort the photon histogram and cause depth errors. To realize high accuracy TCSPC depth imaging with a shorter acquisition time, we propose a high-flux fast photon-counting 3D imaging method based on empirical depth error correction. First, we derive the photon flux estimation formula and calculate the depth error of our photon-counting lidar under different photon fluxes with experimental data. Then, a function correction model between the depth errors and the number of echo photons is established by numerical fitting. Finally, the function correction model is used to correct depth images at high photon flux with different acquisition times. Experimental results show that the empirical error correction method can shorten the image acquisition time by about one order of magnitude while ensuring a moderate accuracy of the depth image.
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Chef, Samuel, Chung Tah Chua et Chee Lip Gan. « Machine Learning for Time-Resolved Emission : Image Resolution Enhancement ». EDFA Technical Articles 23, no 3 (1 août 2021) : 24–31. http://dx.doi.org/10.31399/asm.edfa.2021-3.p024.

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Abstract This article describes a novel method for improving image resolution achieved using time-resolved photon emission techniques. Instead of directly generating images from photon counting, all detected photons are displayed as a point cloud in 3D space and a new higher-resolution image is generated based on probability density functions associated with photon distributions. Unsupervised learning algorithms identify photon distribution patterns as well as fainter emission sources.
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Sergienko, Alexander V. « Beyond single-photon counting ». Nature Photonics 2, no 5 (mai 2008) : 268–69. http://dx.doi.org/10.1038/nphoton.2008.59.

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Cova, Sergio D., et Massimo Ghioni. « Single-Photon Counting Detectors ». IEEE Photonics Journal 3, no 2 (avril 2011) : 274–77. http://dx.doi.org/10.1109/jphot.2011.2130518.

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Karellas, Andrew. « Photon-Counting Digital Mammography ». Academic Radiology 19, no 8 (août 2012) : 913–15. http://dx.doi.org/10.1016/j.acra.2012.05.007.

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Scott, R. Q., et Humio Inaba. « Single photon counting imagery ». Journal of Bioluminescence and Chemiluminescence 4, no 1 (juillet 1989) : 507–11. http://dx.doi.org/10.1002/bio.1170040166.

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Flohr, Thomas, Martin Petersilka, Andre Henning, Stefan Ulzheimer, Jiri Ferda et Bernhard Schmidt. « Photon-counting CT review ». Physica Medica 79 (novembre 2020) : 126–36. http://dx.doi.org/10.1016/j.ejmp.2020.10.030.

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Perroud, Thomas D., Bo Huang, Mark I. Wallace et Richard N. Zare. « Photon Counting Histogram for One-Photon Excitation ». ChemPhysChem 4, no 10 (7 octobre 2003) : 1121–23. http://dx.doi.org/10.1002/cphc.200300824.

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Perroud, Thomas D., Bo Huang, Mark I. Wallace et Richard N. Zare. « Photon Counting Histogram for One-Photon Excitation ». ChemPhysChem 4, no 12 (8 décembre 2003) : 1280. http://dx.doi.org/10.1002/cphc.200390122.

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LESTONE, J. P. « BLACK-BODY PHOTON CLUSTERING BY SEMICLASSICAL MEANS ». Modern Physics Letters A 23, no 15 (20 mai 2008) : 1067–77. http://dx.doi.org/10.1142/s0217732308027199.

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If stimulated emission could be turned off, then only uncorrelated photons would be emitted from black bodies and the photon counting statistics would be Poissonian. Through the process of stimulated emission, some fraction of the photons emitted from a black body are correlated and thus emitted in clusters. This photon clustering can be calculated by semiclassical means. The corresponding results are in agreement with quantum theory.
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Ma, Yue, Wenhao Zhang, Jinyan Sun, Guoyuan Li, Xiao Wang, Song Li et Nan Xu. « Photon-Counting Lidar : An Adaptive Signal Detection Method for Different Land Cover Types in Coastal Areas ». Remote Sensing 11, no 4 (25 février 2019) : 471. http://dx.doi.org/10.3390/rs11040471.

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Airborne or space-borne photon-counting lidar can provide successive photon clouds of the Earth’s surface. The distribution and density of signal photons are very different because different land cover types have different surface profiles and reflectance, especially in coastal areas where the land cover types are various and complex. A new adaptive signal photon detection method is proposed to extract the signal photons for different land cover types from the raw photons captured by the MABEL (Multiple Altimeter Beam Experimental Lidar) photon-counting lidar in coastal areas. First, the surface types with 30 m resolution are obtained via matching the geographic coordinates of the MABEL trajectory with the NLCD (National Land Cover Database) datasets. Second, in each along-track segment with a specific land cover type, an improved DBSCAN (Density-Based Spatial Clustering of Applications with Noise) algorithm with adaptive thresholds and a JONSWAP (Joint North Sea Wave Project) wave algorithm is proposed and integrated to detect signal photons on different surface types. The result in Pamlico Sound indicates that this new method can effectively detect signal photons and successfully eliminate noise photons below the water level, whereas the MABEL result failed to extract the signal photons in vegetation segments and failed to discard the after-pulsing noise photons. In the Atlantic Ocean and Pamlico Sound, the errors of the RMS (Root Mean Square) wave height between our result and in-situ result are −0.06 m and 0.00 m, respectively. However, between the MABEL and in-situ result, the errors are −0.44 m and −0.37 m, respectively. The mean vegetation height between the East Lake and Pamlico Sound was also calculated as 15.17 m using the detecting signal photons from our method, which agrees well with the results (15.56 m) from the GFCH (Global Forest Canopy Height) dataset. Overall, for different land cover types in coastal areas, our study indicates that the proposed method can significantly improve the performance of the signal photon detection for photon-counting lidar data, and the detected signal photons can further obtain the water levels and vegetation heights. The proposed approach can also be extended for ICESat-2 (Ice, Cloud, and land Elevation Satellite-2) datasets in the future.
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Caccia, Michele, Elisa Camozzi, Maddalena Collini, Manuela Zaccolo et Giuseppe Chirico. « Photon Moment Analysis in Cells in the Presence of Photo-Bleaching ». Applied Spectroscopy 59, no 2 (février 2005) : 227–36. http://dx.doi.org/10.1366/0003702053084981.

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The photon counting histogram (PCH) analysis of the fluorescence fluctuations provides the molecular brightness (ε) and the average number of fluorophores (〈Nn〉) in an open observation volume. PCH, which is based on the analysis of the whole of the photon counting histogram, has been recently improved by taking into account the detector dead time effect, which is relevant at high fluorescence rates. We investigate here the possibility of quantitatively applying the PCH analysis in the simplified form of photon moment analysis, in which only the first two moments of the photon counting histogram are computed. We have applied this analysis to low fluorescence signals from living cells in the presence of cell micro-movements and molecular photo-bleaching and describe a simple algorithm for its routine application. The algorithm has been tested on Saccharomyces Cerevisiæ (yeast) cells labeled with Dimethyl-pepep and Rhodamine 6G, and Chinese Hamster Ovary (CHO) cells stably expressing the regulatory subunit (RII) of protein kinase A fused to the cyan-emitting variant of GFP (CFP). Our statistical analysis allows us to estimate the local concentrations and the brightness of the fluorophores in different cellular compartments (nucleus, membrane, and cytoplasm) despite the occurrence of microscopic cell movements and significant photo-bleaching.
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Shen, Xue, Wei Kong, Peng Chen, Tao Chen, Genghua Huang et Rong Shu. « A Shipborne Photon-Counting Lidar for Depth-Resolved Ocean Observation ». Remote Sensing 14, no 14 (12 juillet 2022) : 3351. http://dx.doi.org/10.3390/rs14143351.

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Depth-resolved information is essential for ocean research. For this study, we developed a shipborne photon-counting lidar for depth-resolved oceanic plankton observation. A pulsed fiber laser with frequency doubling to 532 nm acts as a light source, generating a single pulse at the micro-joule level with a pulse width of less than 1 ns. The receiver is capable of simultaneously detecting the elastic signal at two orthogonal polarization states, the Raman scattering from seawater, and the fluorescence signal from chlorophyll A. The data acquisition system utilizes the photon-counting technique to record each photon event, after which the backscattering signal intensity can be recovered by counting photons from multiple pulses. Benefitting from the immunity of this statistical detection method to the ringing effect of the detector and amplifier circuit, high-sensitivity and high-linearity backscatter signal measurements are realized. In this paper, we analyze and correct the after-pulse phenomenon of high-linearity signals through experiments and theoretical simulations. Through the after-pulse correction, the lidar attenuation coefficient retrieved from the corrected signal are in good agreement with the diffuse attenuation coefficients calculated from the in situ instrument, indicating the potential of this shipborne photon-counting lidar for ocean observation applications.
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Xia, Z. Q. « FLASH LiDAR SINGLE PHOTON IMAGING OVER 50 KM ». International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLVIII-1/W2-2023 (13 décembre 2023) : 1601–6. http://dx.doi.org/10.5194/isprs-archives-xlviii-1-w2-2023-1601-2023.

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Abstract. In order to demonstrate the feasibility of single-photon imaging of flash lidar in the permanent shadow area of the moon, a set of space-based single-photon imaging system is designed, including the lidar based on VCSEL array, the optical emitting system based on the uniform beam shaping meta-lens using propagation phase and geometric phase joint control method, the two-axis three-mirror optical receiving system, and the single-photon detector array based on photon counting mode. According to the heavy-tailed pulse laser function, Poisson statistical filtering theory and Monte Carlo simulation method, the echo photon number, the photon counting process, the ranging accuracy and the intensity image are simulated in the condition of 50 km detection distance by setting different of the object reflectivity, the repetition times and the gating interval time. The results show that according to the parameter settings in this paper, the number of echo photons is as low as about 10-4 orders. However, the photon counting waveform can better restore the transmission waveform. The setting of the repetition number and the gating interval time should not only consider the missing detection phenomenon, but also consider the noise accumulation. When the repetition number is 2000 and the gate number is 200, the ranging accuracy can reach 0.075m, and the imaging in the crater without light is realized.
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Song, Yue, Yue Ma, Zhibiao Zhou, Jian Yang et Song Li. « Signal Photon Extraction and Classification for ICESat-2 Photon-Counting Lidar in Coastal Areas ». Remote Sensing 16, no 7 (22 mars 2024) : 1127. http://dx.doi.org/10.3390/rs16071127.

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The highly accurate data of topography and bathymetry are fundamental to ecological studies and policy decisions for coastal zones. Currently, the automatic extraction and classification of signal photons in coastal zones is a challenging problem, especially the surface type classification without auxiliary data. The lack of classification information limits large-scale bathymetric applications of ICESat-2 (Ice, Cloud, and Land Elevation Satellite-2). In this study, we propose a photon extraction–classification method to process geolocated photons in coastal areas from the ICESat-2 ATL03 product. The basic idea is to extract the signal photons using an adaptive photon clustering algorithm, and the extracted signal photons are classified based on the accumulated histogram and triangular grid. We also generate the bottom profile using the weighted interpolation. In four typical coastal areas (artificial coast, natural coast, island, and reefs), the extraction accuracy of a signal photons exceeds 0.90, and the Kappa coefficients of four surface types exceed 0.75. This method independently extracts and classifies signal photons without relying on auxiliary data, which can greatly improve the efficiency of obtaining bathymetric points in all kinds of coastal areas and provide technical support for other coastal studies using ICESat-2 data.
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Jemian, P. R., et G. G. Long. « Silicon photodiode detector for small-angle X-ray scattering ». Journal of Applied Crystallography 23, no 5 (1 octobre 1990) : 430–32. http://dx.doi.org/10.1107/s0021889890005167.

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A photodiode X-ray detector was built to measure small-angle X-ray scattering (SAXS) at a synchrotron-radiation source in conjunction with a double-crystal diffractometer SAXS camera at photon energies between 5 and 11 keV. The photodiode detector response in this energy range is linear at photon counting rates up to 1012 photons s−1 and thus it was not necessary to attenuate the monochromatic X-ray beam with calibrated foils. SAXS data taken with a scintillation counter and the photodiode detector are compared, demonstrating marked improvement in counting statistics, rate of data acquisition and signal-to-noise ratio.
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Li, Yingrui, Gangqiang Zha, Yu Guo, Shouzhi Xi, Lingyan Xu et Wanqi Jie. « Investigation on X-ray Photocurrent Response of CdZnTe Photon Counting Detectors ». Sensors 20, no 2 (9 janvier 2020) : 383. http://dx.doi.org/10.3390/s20020383.

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Counting rate is an important factor for CdZnTe photon counting detectors as high-flux devices. Until recently, there has been a lack of knowledge on the relationship between X-ray photocurrent response and the photon counting performance of CdZnTe detectors. In this paper, the performance of linear array 1 × 16-pixel CdZnTe photon counting detectors operated under different applied biases is investigated. The relation between experimental critical flux and applied bias show an approximate quadratic dependence, which agrees well the theoretical prediction. The underlying relationship among X-ray photocurrents, carrier transport properties, and photon counting performance was obtained by analyzing X-ray current–voltage and time current curves. The typical X-ray photocurrent curve can be divided into three regions, which may be explained by the photoconductive gain mechanism and electric field distortion characteristics. To keep CdZnTe photon counting detectors working in a “non-polarized state”, the applied bias should be set on the left side of the “valley region” (high bias direction) in the X-ray I-V curves. This provides an effective measurement for determining the proper working bias of CdZnTe detectors and screening photon counting detector crystals.
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Ortolano, Giuseppe, Elena Losero, Stefano Pirandola, Marco Genovese et Ivano Ruo-Berchera. « Experimental quantum reading with photon counting ». Science Advances 7, no 4 (janvier 2021) : eabc7796. http://dx.doi.org/10.1126/sciadv.abc7796.

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The final goal of quantum hypothesis testing is to achieve quantum advantage over all possible classical strategies. In the protocol of quantum reading, this is achieved for information retrieval from an optical memory, whose generic cell stores a bit of information in two possible lossy channels. We show, theoretically and experimentally, that quantum advantage is obtained by practical photon-counting measurements combined with a simple maximum-likelihood decision. In particular, we show that this receiver combined with an entangled two-mode squeezed vacuum source is able to outperform any strategy based on statistical mixtures of coherent states for the same mean number of input photons. Our experimental findings demonstrate that quantum entanglement and simple optics are able to enhance the readout of digital data, paving the way to real applications of quantum reading and with potential applications for any other model that is based on the binary discrimination of bosonic loss.
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Krzyzanowska, A. « Measurements of charge sharing in a hybrid pixel photon counting CdTe detector ». Journal of Instrumentation 16, no 12 (1 décembre 2021) : C12027. http://dx.doi.org/10.1088/1748-0221/16/12/c12027.

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Abstract Hybrid pixel radiation detectors working in a single-photon counting mode have gained increasing attention due to their noiseless imaging and high dynamic range. Due to the fact that sensors of different materials can be attached to the readout circuit, they allow operation with a wide range of photon energies. The performance of the single photon counting detectors is limited by pile-up. To allow a detector to work under high flux conditions, the pixel size is reduced, which minimizes detector dead time. However, with smaller pixel sizes the charge sharing effect, a phenomenon that deteriorates both detection efficiency and spatial resolution is more profound. The influence of charge sharing on the detector performance can be quantified using parameterization of the s-curve obtained in the spectral response measurements. The article presents the measurements of the response function of a hybrid pixelated photon counting detector for certain primary energy, which corresponds to the probability of detecting a photon as a function of its energy deposition. The measurements were carried out using an X-ray tube by performing a threshold scan during illumination with X-ray photons of a 1.5 mm and 0.75 mm thick CdTe detector with 100 µm pixel pitch. The charge size cloud depends on the sensor material, the bias voltage, and the sensor thickness. Therefore, the experimental data from a sensor biased with different bias voltages are compared to the theoretical results based on a cascaded model of a single-photon counting segmented silicon detector. The study of the charge sharing influence on the spatial resolution of the CdTe detector will serve for a further study of the possible implementations of the algorithms achieving subpixel resolution, in which the charge sharing becomes the desired effect since the charge division in the pixels is used to interpolate the photon interaction position.
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Griffiths, Alexander, Johannes Herrnsdorf, Christopher Lowe, Malcolm Macdonald, Robert Henderson, Michael Strain et Martin Dawson. « Temporal Encoding to Reject Background Signals in a Low Complexity, Photon Counting Communication Link ». Materials 11, no 9 (9 septembre 2018) : 1671. http://dx.doi.org/10.3390/ma11091671.

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Communicating information at the few photon level typically requires some complexity in the transmitter or receiver in order to operate in the presence of noise. This in turn incurs expense in the necessary spatial volume and power consumption of the system. In this work, we present a self-synchronised free-space optical communications system based on simple, compact and low power consumption semiconductor devices. A temporal encoding method, implemented using a gallium nitride micro-LED source and a silicon single photon avalanche photo-detector (SPAD), demonstrates data transmission at rates up to 100 kb/s for 8.25 pW received power, corresponding to 27 photons per bit. Furthermore, the signals can be decoded in the presence of both constant and modulated background noise at levels significantly exceeding the signal power. The system’s low power consumption and modest electronics requirements are demonstrated by employing it as a communications channel between two nano-satellite simulator systems.
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42

Zhu, Xiaoxiao, Sheng Nie, Cheng Wang, Xiaohuan Xi et Zhenyue Hu. « A Ground Elevation and Vegetation Height Retrieval Algorithm Using Micro-Pulse Photon-Counting Lidar Data ». Remote Sensing 10, no 12 (6 décembre 2018) : 1962. http://dx.doi.org/10.3390/rs10121962.

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The Ice, Cloud and Land Elevation Satellite-2 (ICESat-2) mission employs a micro-pulse photon-counting LiDAR system for mapping and monitoring the biomass and carbon of terrestrial ecosystems over large areas. In preparation for ICESat-2 data processing and applications, this paper aimed to develop and validate an effective algorithm for better estimating ground elevation and vegetation height from photon-counting LiDAR data. Our new proposed algorithm consists of three key steps. Firstly, the noise photons were filtered out using a noise removal algorithm based on localized statistical analysis. Secondly, we classified the signal photons into canopy photons and ground photons by conducting a series of operations, including elevation frequency histogram building, empirical mode decomposition (EMD), and progressive densification. At the same time, we also identified the top of canopy (TOC) photons from canopy photons by percentile statistics method. Thereafter, the ground and TOC surfaces were generated from ground photons and TOC photons by cubic spline interpolation, respectively. Finally, the ground elevation and vegetation height were estimated by retrieved ground and TOC surfaces. The results indicate that the noise removal algorithm is effective in identifying background noise and preserving signal photons. The retrieved ground elevation is more accurate than the retrieved vegetation height, and the results of nighttime data are better than those of the corresponding daytime data. Specifically, the root-mean-square error (RMSE) values of ground elevation estimates range from 2.25 to 6.45 m for daytime data and 2.03 to 6.03 m for nighttime data. The RMSE values of vegetation height estimates range from 4.63 to 8.92 m for daytime data and 4.55 to 8.65 m for nighttime data. Our algorithm performs better than the previous algorithms in estimating ground elevation and vegetation height due to lower RMSE values. Additionally, the results also illuminate that the photon classification algorithm effectively reduces the negative effects of slope and vegetation coverage. Overall, our paper provides an effective solution for estimating ground elevation and vegetation height from micro-pulse photon-counting LiDAR data.
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43

Cha, Wonhee, Won-Young Cha, Insub Noh, Shu Seki, Hideo Ohkita et Dongho Kim. « Controlling the charge carrier dynamics by modulating the orientation diversity of perovskites ». Materials Chemistry Frontiers 6, no 8 (2022) : 1026–32. http://dx.doi.org/10.1039/d1qm01586a.

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Photo-induced charge carrier dynamics over a wide time domain from sub-nanoseconds to microseconds, via time-correlated single photon counting and flash photolysis time-resolved microwave conductivity measurements.
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44

Hutchings, J. B., J. Postma, D. Asquin et D. Leahy. « Photon Event Centroiding with UV Photon‐counting Detectors ». Publications of the Astronomical Society of the Pacific 119, no 860 (octobre 2007) : 1152–62. http://dx.doi.org/10.1086/522635.

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Loureiro, Jamir S., Paulo A. L. da Cruz, Akira Iwahara, José U. Delgado et Ricardo T. Lopes. « 65Zn and133Ba standardizing by photon-photon coincidence counting ». Journal of Physics : Conference Series 975 (mars 2018) : 012040. http://dx.doi.org/10.1088/1742-6596/975/1/012040.

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Adam, Martin, Roger Durst, Bruce Becker et Joerg Kaercher. « A photon-counting large-area detector – PHOTON III ». Acta Crystallographica Section A Foundations and Advances 73, a2 (1 décembre 2017) : C1143. http://dx.doi.org/10.1107/s2053273317084315.

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Mrosek, Michael, Martin Adam, Bruce Becker, Roger Durst et Joerg Kaercher. « A photon-counting large-area detector – PHOTON III ». Acta Crystallographica Section A Foundations and Advances 74, a2 (22 août 2018) : e297-e297. http://dx.doi.org/10.1107/s205327331809071x.

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48

Klempka, Anna, Eduardo Ackermann, Stefanie Brehmer, Sven Clausen et Christoph Groden. « Advanced Imaging of Shunt Valves in Cranial CT Scans with Photon-Counting Scanner ». Tomography 10, no 5 (25 avril 2024) : 654–59. http://dx.doi.org/10.3390/tomography10050050.

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This brief report aimed to show the utility of photon-counting technology alongside standard cranial imaging protocols for visualizing shunt valves in a patient’s cranial computed tomography scan. Photon-counting CT scans with cranial protocols were retrospectively surveyed and four types of shunt valves were encountered: proGAV 2.0®, M.blue®, Codman Certas®, and proSA®. These scans were compared with those obtained from non-photon-counting scanners at different time points for the same patients. The analysis of these findings demonstrated the usefulness of photon-counting technology for the clear and precise visualization of shunt valves without any additional radiation or special reconstruction patterns. The enhanced utility of photon-counting is highlighted by providing superior spatial resolution compared to other CT detectors. This technology facilitates a more accurate characterization of shunt valves and may support the detection of subtle abnormalities and a precise assessment of shunt valves.
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Xiang, Yu-Yan, Song Li et Yue Ma. « Effect of pile-up of electron flow pulse from photomultiplier tube on ranging by photon counting ». Acta Physica Sinica 71, no 21 (2022) : 214206. http://dx.doi.org/10.7498/aps.71.20220537.

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Photomultiplier tube (PMT) features single photon level sensitivity, low dark count, and low afterpulse probability, and are widely used in photon-counting lidar in the visible spectrum. The PMT has no photon detection dead time, for every photon it responds to, it can output an electron flow pulse, these pulses of electron flow are likely to pile up into larger pulses. When using threshold identification method to identify photon-events, the stacked pulse will introduce additional pulse walking error, directly affecting the ranging precision of photon-counting ranging method in the practical application of laser ranging. Considering the influence of pulse pile-up, a new theoretical model of PMT photon detection is established to describe the influence of pulse pile-up on the detection probability of photon-events by analyzing the relationship between the detection time of photon and the identification time of the PMT final output photon-events. Through Monte Carlo simulation, the relationship among the ranging walking error, ranging accuracy, incident laser pulse width, PMT output electron flow pulse width and photon-events identification threshold is obtained. In order to verify the correctness of the theory, a PMT-based photon-counting lidar system is built. The comparative experiment with GM-APD proves that the influence of pulse pile-up on PMT photon-counting ranging method cannot be ignored, and that the experimental results are in good agreement with results from the theoretical model. The PMT photon detection model based on pulse pile-up can guide the design of PMT photon-counting radar and improve the ranging accuracy and precision of the ranging system.
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Ha, Jin-Ung, Hyun-Woo Kim, Myungjin Cho et Min-Chul Lee. « A Method for Visualization of Images by Photon-Counting Imaging Only Object Locations under Photon-Starved Conditions ». Electronics 13, no 1 (20 décembre 2023) : 38. http://dx.doi.org/10.3390/electronics13010038.

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Recently, many researchers have been studying the visualization of images and the recognition of objects by estimating photons under photon-starved conditions. Conventional photon-counting imaging techniques estimate photons by way of a statistical method using Poisson distribution in all image areas. However, Poisson distribution is temporally and spatially independent, and the reconstructed image has a random noise in the background. Random noise in the background may degrade the quality of the image and make it difficult to accurately recognize objects. Therefore, in this paper, we apply photon-counting imaging technology only to the area where the object is located to eliminate the noise in the background. As a result, it can be seen that the image quality using the proposed method is better than that of the conventional method and the object recognition rate is also higher. Optical experiments were conducted to prove the denoising performance of the proposed method. In addition, we used the structure similarity index measure (SSIM) as a performance metric. To check the recognition rate of the object, we applied the YOLOv5 model. Finally, the proposed method is expected to accelerate the development of astrophotography and medical imaging technologies.
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