Single-photon detectors possess the ultra-high sensitivity, but they cannot directly respond to signal intensity. Conven- tional methods adopt sampling gates with fixed width and count the triggered number of sampling...Single-photon detectors possess the ultra-high sensitivity, but they cannot directly respond to signal intensity. Conven- tional methods adopt sampling gates with fixed width and count the triggered number of sampling gates, which is capable of obtaining photon counting probability to estimate the echo signal intensity. In this paper, we not only count the number of triggered sampling gates, but also record the triggered time position of photon counting pulses. The photon counting probability density distribution is obtained through the statistics of a series of the triggered time positions. Then Minimum Variance Unbiased Estimation （MVUE） method is used to estimate the echo signal intensity. Compared with conventional methods, this method can improve the estimation accuracy of echo signal intensity due to the acquisition of more detected information. Finally, a proof-of-principle laboratory system is established. The estimation accuracy of echo signal intensity is discussed and a high accuracy intensity image is acquired under low-light level environments.展开更多
A novel FPGA-based pulse pile-up rejection method for single photon imaging detectors is reported. Tile method is easy to implement in FPGAs for real-time data processing. The rejection principle and entire design are...A novel FPGA-based pulse pile-up rejection method for single photon imaging detectors is reported. Tile method is easy to implement in FPGAs for real-time data processing. The rejection principle and entire design are introduced in detail. The photon counting imaging detector comprises a micro-channel plate （MCP） stack, and a wedge and strip anode （WSA）. The resolution mask pattern in front of the MCP can be reconstructed after data processing in the FPGA. For high count rates, the rejection design can effectively reduce the impact of the pulse pile-up on the image. The resolution can reach up to 140μm. The pulse pile-up rejection design can also be applied to high-energy physics and particle detection.展开更多
Photon counting detectors(PCDs) have attained w ide use in X-ray imaging for various preclinical and clinical applications in the past decade. This paper briefly review s the preclinical and clinical applications of P...Photon counting detectors(PCDs) have attained w ide use in X-ray imaging for various preclinical and clinical applications in the past decade. This paper briefly review s the preclinical and clinical applications of PCDs based X-ray imaging systems.Starting with an introduction of X-ray single photon detection mechanism,the brief review first describes tw o major advantages of utilizing PCDs: photon energy resolving capability and electronic noise elimination. Compared to energy integrating detectors(EIDs),the aforementioned advantages make PCDs more favorable in X-ray imaging with profound benefits such as enhanced tissue contrast,decreased image noise,increased signal to noise ratio,decreased radiation dose to the small animals and patients,and more accurate material decomposition. The utilizations of PCDs in X-ray projection radiography and computed tomography(CT)including micro-CT,dedicated breast CT,K-edge CT,and clinical CT are then review ed for the imaging applications ranging from phantoms to small animals and humans. In addition,optimization methods aiming to improve the imaging performance using PCDs are briefly review ed. PCDs are not flaw less though,and their limitations are also discussed in this review. Nevertheless,PCDs may continuously contribute to the advancement of X-ray imaging techniques in future preclinical and clinical applications.展开更多
Optical spectrum analysis provides a wealth of information about the physical world.Throughout the development of optical spectrum analysis,sensitivity has been one of the major topics and has become essential in appl...Optical spectrum analysis provides a wealth of information about the physical world.Throughout the development of optical spectrum analysis,sensitivity has been one of the major topics and has become essential in applications dealing with faint light.Various high-sensitivity optical detection technologies have been applied in optical spectrum analysis to enhance its sensitivity to single-photon level.As an emerging single-photon detection technology,superconducting nanowire single-photon detectors(SNSPDs)have many impressive features such as high detection efficiency,broad operation bandwidth,small timing jitter,and so on,which make them promising for enhancing the performance of optical spectral analysis.Diverse schemes for photon-counting spectrometers based on SNSPDs have been demonstrated.This article reviews these impressive works and prospects for the future development of this technology.Further breakthroughs can be expected in its theories,device performance,applications,and combinations with in-sensor computing,promoting it to be a mature and versatile solution for optical spectrum analysis on ultra-faint light.展开更多
X-ray charge-coupled-device（CCD） camera working in single photon counting mode is a type of x-ray spectrometer with high-sensitivity and superior signal-to-noise performance. In this study, two single photon countin...X-ray charge-coupled-device（CCD） camera working in single photon counting mode is a type of x-ray spectrometer with high-sensitivity and superior signal-to-noise performance. In this study, two single photon counting CCD cameras with the same mode（model： PI-LCX： 1300） are calibrated with quasi-monochromatic x-rays from radioactive sources and a conventional x-ray tube. The details of the CCD response to x-rays are analyzed by using a computer program of multi-pixel analyzing and event-distinguishing capability. The detection efficiency, energy resolution, fraction of multi-pixel events each as a function of x-ray energy, and consistence of two CCD cameras are obtained. The calibrated detection efficiency is consistent with the detection efficiency from Monte Carlo calculations with XOP program. When the multi-pixel event analysis is applied, the CCDs may be used to measure x-rays up to 60 ke V with good energy resolution（E /？E ≈ 100 at60 ke V）. The difference in detection efficiency between two CCD cameras is small（5.6% at 5.89 ke V）, but the difference in fraction of the single pixel event between them is much larger（25% at 8.04 ke V）. The obtained small relative error of detection efficiency（2.4% at 5.89 ke V） makes the high accurate measurement of x-ray yield possible in the laser plasma interaction studies. Based on the discrete calibration results, the calculated detection efficiency with XOP can be used for the whole range of 5 ke V–30 ke V.展开更多
Photon number resolving detectors with high accuracy bring broad applications in long-distance laser ranging, ultrafast spectroscopy, and quantum optics. In this paper, we observed the non-classical photon number dist...Photon number resolving detectors with high accuracy bring broad applications in long-distance laser ranging, ultrafast spectroscopy, and quantum optics. In this paper, we observed the non-classical photon number distribution directly with a multi-pixel photon counter (MPPC) instead of a classic Hanbury-Brown and Twiss (HBT) system. The detector’s photon-number resolving ability was characterized by quantum detector tomography. To show the quantum feature of the detector, we further plotted the Wigner function, which was obtained corresponding to the positive operator value measure (POVM) elements. Finally, we declared the observation of non-classical photon statistics from a single color center in nanodiamond by using this detector.展开更多
基金supported by the Fundamental Research Funds for the Central Universities,China(Grant No.AUGA5710056414)the Program for Innovation Research of Science in Harbin Institute of Technology(Grant Nos.PIRS OF HIT A201412 and PIRS OF HIT Q201505)+3 种基金the National Natural Science Foundation of China(Grant No.11675046)the Doctoral Fund of the Ministry of Education of China(Grant No.20122302120003)the Natural Science Foundation of Heilongjiang Province of China(Grant No.A201303)the Postdoctoral Scientific Research Developmental Fund of Heilongjiang Province,China(Grant No.LBH-Q15060)
文摘Single-photon detectors possess the ultra-high sensitivity, but they cannot directly respond to signal intensity. Conven- tional methods adopt sampling gates with fixed width and count the triggered number of sampling gates, which is capable of obtaining photon counting probability to estimate the echo signal intensity. In this paper, we not only count the number of triggered sampling gates, but also record the triggered time position of photon counting pulses. The photon counting probability density distribution is obtained through the statistics of a series of the triggered time positions. Then Minimum Variance Unbiased Estimation （MVUE） method is used to estimate the echo signal intensity. Compared with conventional methods, this method can improve the estimation accuracy of echo signal intensity due to the acquisition of more detected information. Finally, a proof-of-principle laboratory system is established. The estimation accuracy of echo signal intensity is discussed and a high accuracy intensity image is acquired under low-light level environments.
基金Supported by the National Natural Science Foundation of China under Grant No 11375179
文摘A novel FPGA-based pulse pile-up rejection method for single photon imaging detectors is reported. Tile method is easy to implement in FPGAs for real-time data processing. The rejection principle and entire design are introduced in detail. The photon counting imaging detector comprises a micro-channel plate （MCP） stack, and a wedge and strip anode （WSA）. The resolution mask pattern in front of the MCP can be reconstructed after data processing in the FPGA. For high count rates, the rejection design can effectively reduce the impact of the pulse pile-up on the image. The resolution can reach up to 140μm. The pulse pile-up rejection design can also be applied to high-energy physics and particle detection.
基金supported in part by a grant from the University of Oklahoma Charles and Peggy Stephenson Cancer Center funded by the Oklahoma Tobacco Settlement Endowment Trust
文摘Photon counting detectors(PCDs) have attained w ide use in X-ray imaging for various preclinical and clinical applications in the past decade. This paper briefly review s the preclinical and clinical applications of PCDs based X-ray imaging systems.Starting with an introduction of X-ray single photon detection mechanism,the brief review first describes tw o major advantages of utilizing PCDs: photon energy resolving capability and electronic noise elimination. Compared to energy integrating detectors(EIDs),the aforementioned advantages make PCDs more favorable in X-ray imaging with profound benefits such as enhanced tissue contrast,decreased image noise,increased signal to noise ratio,decreased radiation dose to the small animals and patients,and more accurate material decomposition. The utilizations of PCDs in X-ray projection radiography and computed tomography(CT)including micro-CT,dedicated breast CT,K-edge CT,and clinical CT are then review ed for the imaging applications ranging from phantoms to small animals and humans. In addition,optimization methods aiming to improve the imaging performance using PCDs are briefly review ed. PCDs are not flaw less though,and their limitations are also discussed in this review. Nevertheless,PCDs may continuously contribute to the advancement of X-ray imaging techniques in future preclinical and clinical applications.
基金supported by the National Key R&D Program of China(Grant No.2023YFB2806700)the National Natural Science Foundation of China(Grant No.92365210)the Tsinghua Initiative Scientific Research Program,and the project of Tsinghua University-Zhuhai Huafa Industrial Share Company Joint Institute for Architecture Optoelectronic Technologies(JIAOT).
文摘Optical spectrum analysis provides a wealth of information about the physical world.Throughout the development of optical spectrum analysis,sensitivity has been one of the major topics and has become essential in applications dealing with faint light.Various high-sensitivity optical detection technologies have been applied in optical spectrum analysis to enhance its sensitivity to single-photon level.As an emerging single-photon detection technology,superconducting nanowire single-photon detectors(SNSPDs)have many impressive features such as high detection efficiency,broad operation bandwidth,small timing jitter,and so on,which make them promising for enhancing the performance of optical spectral analysis.Diverse schemes for photon-counting spectrometers based on SNSPDs have been demonstrated.This article reviews these impressive works and prospects for the future development of this technology.Further breakthroughs can be expected in its theories,device performance,applications,and combinations with in-sensor computing,promoting it to be a mature and versatile solution for optical spectrum analysis on ultra-faint light.
基金Project supported by the Science Foundation of China Academy of Engineering Physics(Grant Nos.2013A0103003 and 2012B0102008)the National High-Tech Inertial Confinement Fusion Committee of China
文摘X-ray charge-coupled-device（CCD） camera working in single photon counting mode is a type of x-ray spectrometer with high-sensitivity and superior signal-to-noise performance. In this study, two single photon counting CCD cameras with the same mode（model： PI-LCX： 1300） are calibrated with quasi-monochromatic x-rays from radioactive sources and a conventional x-ray tube. The details of the CCD response to x-rays are analyzed by using a computer program of multi-pixel analyzing and event-distinguishing capability. The detection efficiency, energy resolution, fraction of multi-pixel events each as a function of x-ray energy, and consistence of two CCD cameras are obtained. The calibrated detection efficiency is consistent with the detection efficiency from Monte Carlo calculations with XOP program. When the multi-pixel event analysis is applied, the CCDs may be used to measure x-rays up to 60 ke V with good energy resolution（E /？E ≈ 100 at60 ke V）. The difference in detection efficiency between two CCD cameras is small（5.6% at 5.89 ke V）, but the difference in fraction of the single pixel event between them is much larger（25% at 8.04 ke V）. The obtained small relative error of detection efficiency（2.4% at 5.89 ke V） makes the high accurate measurement of x-ray yield possible in the laser plasma interaction studies. Based on the discrete calibration results, the calculated detection efficiency with XOP can be used for the whole range of 5 ke V–30 ke V.
基金supported by the National Natural Science Foundation of China under Grants No.11722431,No.11674099,No.11704127,and No.11621404the Program of Introducing Talents of Discipline to Universities under Grant No.B12024+2 种基金the Shanghai International Cooperation Project under Grant No.16520710600the Natural Science Foundation of Shanghai under Grant No.16ZR1409400the Shuguang Program under Grant No.15SG22 by Shanghai Education Development Foundation and Shanghai Municipal Education Commission
文摘Photon number resolving detectors with high accuracy bring broad applications in long-distance laser ranging, ultrafast spectroscopy, and quantum optics. In this paper, we observed the non-classical photon number distribution directly with a multi-pixel photon counter (MPPC) instead of a classic Hanbury-Brown and Twiss (HBT) system. The detector’s photon-number resolving ability was characterized by quantum detector tomography. To show the quantum feature of the detector, we further plotted the Wigner function, which was obtained corresponding to the positive operator value measure (POVM) elements. Finally, we declared the observation of non-classical photon statistics from a single color center in nanodiamond by using this detector.
