Compressed ultrafast photography(CUP)is a burgeoning single-shot computational imaging technique that provides an imaging speed as high as 10 trillion frames per second and a sequence depth of up to a few hundred fram...Compressed ultrafast photography(CUP)is a burgeoning single-shot computational imaging technique that provides an imaging speed as high as 10 trillion frames per second and a sequence depth of up to a few hundred frames.This technique synergizes compressed sensing and the streak camera technique to capture nonrepeatable ultrafast transient events with a single shot.With recent unprecedented technical developments and extensions of this methodology,it has been widely used in ultrafast optical imaging and metrology,ultrafast electron diffraction and microscopy,and information security protection.We review the basic principles of CUP,its recent advances in data acquisition and image reconstruction,its fusions with other modalities,and its unique applications in multiple research fields.展开更多
Orbital angular momentum (OAM) spectrum diagnosis is a fundamental building block for diverseOAM-based systems. Among others, the simple on-axis interferometric measurement can retrieve theamplitude and phase informat...Orbital angular momentum (OAM) spectrum diagnosis is a fundamental building block for diverseOAM-based systems. Among others, the simple on-axis interferometric measurement can retrieve theamplitude and phase information of complex OAM spectra in a few shots. Yet, its single-shot retrievalremains elusive, due to the signal–signal beat interference inherent in the measurement. Here, weintroduce the concept of Kramers–Kronig (KK) receiver in coherent communications to the OAM domain,enabling rigorous, single-shot OAM spectrum measurement. We explain in detail the working principle andthe requirement of the KK method and then apply the technique to precisely measure variouscharacteristic OAM states. In addition, we discuss the effects of the carrier-to-signal power ratio and thenumber of sampling points essential for rigorous retrieval and evaluate the performance on a large set ofrandom OAM spectra and high-dimensional spaces. Single-shot KK interferometry shows enormouspotential for characterizing complex OAM states in real time.展开更多
A new terahertz dispersive device designed for single-shot spectral measurements of broadband terahertz pulses is proposed. With two-dimensional quasi-randomly distributed element design, the device exhibits approxima...A new terahertz dispersive device designed for single-shot spectral measurements of broadband terahertz pulses is proposed. With two-dimensional quasi-randomly distributed element design, the device exhibits approximately the dispersive property of single-order diffraction in far field. Its far-field diffraction pattern is experimentally verified employing a continuous terahertz source centered at 2.52 THz and a pyroelectric focal-plane-array camera, which is in good agreement with the numerical result. The device provides a new approach for direct single-shot spectral measurements of broadband terahertz waves.展开更多
In this paper,a single-shot 360-degree cranial deformity detection system using digital image correlation(DIC)is presented to quickly obtain and detect accurate 3D data of infants’cra-nium.By introducing plane mirror...In this paper,a single-shot 360-degree cranial deformity detection system using digital image correlation(DIC)is presented to quickly obtain and detect accurate 3D data of infants’cra-nium.By introducing plane mirrors into a stereo 3D DIC measurement system,a multi-view 3D imaging model is established to convert 3D data from real and virtual perspectives into 360-degree 3D data of the tested infant cranium,achieving single-shot and panoramic 3D measurement.Exper-imental results showed that the performance and measurement accuracy of the proposed system can meet the requirements for cranial deformity detection,which provides a fast,accurate,and low-cost solution medically.展开更多
Terahertz(THz) waves have shown a broad prospect in the analysis of some dielectric materials because of their special properties. For the ultrafast irreversible processes, the THz single-shot measurement is a good ch...Terahertz(THz) waves have shown a broad prospect in the analysis of some dielectric materials because of their special properties. For the ultrafast irreversible processes, the THz single-shot measurement is a good choice. In this paper,a single-shot system is investigated, where a pump beam is used to generate THz pulses with high electrical field by optical rectification in LiNbO3, the probe beam with wavefront tilted by a blazed grating is used for single-shot measurement. The time window is up to 90 ps, the signal to noise ratio is 2000 : 1, the spectrum covers from 0.1 THz to about 2.0 THz, and the spectral resolution is 0.011 THz. The single-shot measurement result agrees well with that of a traditional electrical-optic sampling method.展开更多
Based on the frequency-to-time mapping relation of the linearly chirped pulse, the temporal phase shift induced by a laser-excited wake in a helium gas jet is measured using a chirped-pulse spectral interferometry wi...Based on the frequency-to-time mapping relation of the linearly chirped pulse, the temporal phase shift induced by a laser-excited wake in a helium gas jet is measured using a chirped-pulse spectral interferometry with ～ 140 fs resolution over a temporal region of I ps in a single shot. In this measurement, the image of the wake is obtained with one-dimensional spatial resolution and temporal resolution limited only by the bandwidth and chirp of the pulse. The ＇bubbles＇ feature of the wake structure, along with multiple wakes excited by the main lobe and the side lobe of a laser focal-spot, is captured simultaneously.展开更多
基金This work was partially supported by the National Natural Science Foundation of China(Grant Nos.91850202,11774094,11727810,11804097,and 61720106009)the Science and Technology Commission of Shanghai Municipality(Grant Nos.19560710300 and 17ZR146900)the China Postdoctoral Science Foundation(Grant No.2018M641958).
文摘Compressed ultrafast photography(CUP)is a burgeoning single-shot computational imaging technique that provides an imaging speed as high as 10 trillion frames per second and a sequence depth of up to a few hundred frames.This technique synergizes compressed sensing and the streak camera technique to capture nonrepeatable ultrafast transient events with a single shot.With recent unprecedented technical developments and extensions of this methodology,it has been widely used in ultrafast optical imaging and metrology,ultrafast electron diffraction and microscopy,and information security protection.We review the basic principles of CUP,its recent advances in data acquisition and image reconstruction,its fusions with other modalities,and its unique applications in multiple research fields.
基金supported by the National Key Research and Development Program of China (2018YFB1801803, 2019YFA0706302)the Basic and Applied Basic Research Foundation of Guangdong Province (2021B1515020093, 2021B1515120057)+1 种基金the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program (2017BT01X121)the Swiss National Science Foundation (P2ELP2_199825)
文摘Orbital angular momentum (OAM) spectrum diagnosis is a fundamental building block for diverseOAM-based systems. Among others, the simple on-axis interferometric measurement can retrieve theamplitude and phase information of complex OAM spectra in a few shots. Yet, its single-shot retrievalremains elusive, due to the signal–signal beat interference inherent in the measurement. Here, weintroduce the concept of Kramers–Kronig (KK) receiver in coherent communications to the OAM domain,enabling rigorous, single-shot OAM spectrum measurement. We explain in detail the working principle andthe requirement of the KK method and then apply the technique to precisely measure variouscharacteristic OAM states. In addition, we discuss the effects of the carrier-to-signal power ratio and thenumber of sampling points essential for rigorous retrieval and evaluate the performance on a large set ofrandom OAM spectra and high-dimensional spaces. Single-shot KK interferometry shows enormouspotential for characterizing complex OAM states in real time.
基金Project supported by the Foundation of Science and Technology Development of China Academy of Engineering Physics(Grant No.2011B0102023)the Foundation of Plasma Physics Laboratory(Grant No.9140C680304110C6806)
文摘A new terahertz dispersive device designed for single-shot spectral measurements of broadband terahertz pulses is proposed. With two-dimensional quasi-randomly distributed element design, the device exhibits approximately the dispersive property of single-order diffraction in far field. Its far-field diffraction pattern is experimentally verified employing a continuous terahertz source centered at 2.52 THz and a pyroelectric focal-plane-array camera, which is in good agreement with the numerical result. The device provides a new approach for direct single-shot spectral measurements of broadband terahertz waves.
基金supported by the National Natural Science Found-ation of China(No.62075096)Leading Technology of Ji-angsu Basic Research Plan(No.BK20192003)+4 种基金National De-fense Science and Technology Foundation of China(No.2019-JCJQ-JJ-381)“333 Engineering”Research Project of Jiangsu Province(No.BRA2016407)Jiangsu Provincial“One Belt and One Road”Innovation Cooperation Project(No.BZ2020007)Fundamental Research Funds for the Central Universities(Nos.30921011208,30919011222 and 30920032101)Open Research Fund of Jiangsu Key Laboratory of Spectral Imaging&Intelligent Sense(No.JS-GP202105).
文摘In this paper,a single-shot 360-degree cranial deformity detection system using digital image correlation(DIC)is presented to quickly obtain and detect accurate 3D data of infants’cra-nium.By introducing plane mirrors into a stereo 3D DIC measurement system,a multi-view 3D imaging model is established to convert 3D data from real and virtual perspectives into 360-degree 3D data of the tested infant cranium,achieving single-shot and panoramic 3D measurement.Exper-imental results showed that the performance and measurement accuracy of the proposed system can meet the requirements for cranial deformity detection,which provides a fast,accurate,and low-cost solution medically.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61427814 and 61575161)the National Key Research and Development Program of China(Grant No.2017YFA0701005)the Natural Science Foundation of Shaanxi Province,China(Grant No.2019JZ-04)。
文摘Terahertz(THz) waves have shown a broad prospect in the analysis of some dielectric materials because of their special properties. For the ultrafast irreversible processes, the THz single-shot measurement is a good choice. In this paper,a single-shot system is investigated, where a pump beam is used to generate THz pulses with high electrical field by optical rectification in LiNbO3, the probe beam with wavefront tilted by a blazed grating is used for single-shot measurement. The time window is up to 90 ps, the signal to noise ratio is 2000 : 1, the spectrum covers from 0.1 THz to about 2.0 THz, and the spectral resolution is 0.011 THz. The single-shot measurement result agrees well with that of a traditional electrical-optic sampling method.
基金Supported by the National Natural Science Foundation of China under Grant No 61377102the Defense Industrial Technology Development Program under Grant No B1520133010
文摘Based on the frequency-to-time mapping relation of the linearly chirped pulse, the temporal phase shift induced by a laser-excited wake in a helium gas jet is measured using a chirped-pulse spectral interferometry with ～ 140 fs resolution over a temporal region of I ps in a single shot. In this measurement, the image of the wake is obtained with one-dimensional spatial resolution and temporal resolution limited only by the bandwidth and chirp of the pulse. The ＇bubbles＇ feature of the wake structure, along with multiple wakes excited by the main lobe and the side lobe of a laser focal-spot, is captured simultaneously.
