Article
Multidisciplinary Sciences
Sheila Seidel, Hoover Rueda-Chacon, Iris Cusini, Federica Villa, Franco Zappa, Christopher Yu, Vivek K. Goyal
Summary: This research demonstrates a non-line-of-sight imaging method that can reconstruct dynamic scenes by utilizing occlusion and a sensor array to estimate the locations and sizes of moving foreground objects and generate a static background map.
NATURE COMMUNICATIONS
(2023)
Article
Computer Science, Artificial Intelligence
Xiaofeng Yang
Summary: Target tracking provides important location-based services, and this paper proposes a novel online sequential learning algorithm IRELM to address the NLOS target tracking problem. IRELM can train RNN inputs one-by-one and adaptively update the weights. Extensive simulations and experiments demonstrate the superior tracking performance and feasible complexity of IRELM over existing Deep Learning methods.
COMPLEX & INTELLIGENT SYSTEMS
(2023)
Letter
Optics
Yasaman Ghasempour, Yasith Amarasinghe, Chia-Yi Yeh, Edward Knightly, Daniel M. Mittleman
Summary: This paper investigates the usage of reflected non-line-of-sight (NLOS) paths for communication in directional networks at frequencies above 100 GHz. The study explores how high-gain directional antennas bring new challenges and opportunities for exploiting NLOS paths, demonstrating that NLOS paths can offer higher data rates under certain circumstances, distinguishing THz wireless systems from those operating at lower frequencies.
Article
Multidisciplinary Sciences
Cheng Wu, Jianjiang Liu, Xin Huang, Zheng-Ping Li, Chao Yu, Jun-Tian Ye, Jun Zhang, Qiang Zhang, Xiankang Dou, Vivek K. Goyal, Feihu Xu, Jian-Wei Pan
Summary: NLOS imaging reconstructs hidden objects from indirect light paths, achieving breakthroughs in long-range imaging. Hardware and software innovations have successfully increased the standoff distance of NLOS imaging, opening up new possibilities for related applications.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Article
Optics
JinHui He, ShuKong Wu, Ran Wei, YuNing Zhang
Summary: This study proposes a deep learning framework combined with a standard RGB camera to achieve object imaging and dynamic tracking. Through simulation experiments and physical scene tests, the method demonstrates superior positioning accuracy and imaging speed. The technique has diverse applications, including security surveillance, military reconnaissance, and autonomous driving.
Article
Engineering, Electrical & Electronic
Jianjiang Liu, Yijun Zhou, Xin Huang, Zheng-Ping Li, Feihu Xu
Summary: Non-line-of-sight (NLOS) imaging techniques have the ability to look around corners, which attracts growing interest for diverse applications. This paper proposes a photon-efficient method to recover hidden scenes using only one detected photon at each scanning point. The method estimates the intensity information and utilizes convex optimization with joint regularization terms to recover the 3D information of the hidden scene. Simulations and experiments show that this method outperforms previous approaches under low-flux conditions.
IEEE TRANSACTIONS ON COMPUTATIONAL IMAGING
(2022)
Article
Engineering, Electrical & Electronic
Jiahui Chen, Shisheng Guo, Haolan Luo, Nian Li, Guolong Cui
Summary: This paper investigates multiple target localization in a non-line-of-sight (NLOS) scenario, and analyzes the propagation paths of electromagnetic waves in an L-shaped NLOS scenario. A multipath echoes model for the multiple-input-multiple-output (MIMO) radar is established. Time of arrivals (ToAs) with respect to different paths are estimated using the matrix pencil algorithm. A path recognition strategy is proposed to pair the ToAs with different types of multipath and targets based on the estimated delays.
IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Ji Hyun Nam, Eric Brandt, Sebastian Bauer, Xiaochun Liu, Marco Renna, Alberto Tosi, Eftychios Sifakis, Andreas Velten
Summary: The study introduces a multipixel time-of-flight non-line-of-sight imaging approach combining array detectors and a fast algorithm, allowing for live reconstruction of scenes with natural non-retroreflective objects.
NATURE COMMUNICATIONS
(2021)
Article
Engineering, Electrical & Electronic
Tian Cao, Xinyu Gao, Tianfeng Wu, Changyong Pan, Jian Song
Summary: This paper proposes a method to improve the received optical power and reduce the path loss in non-line-of-sight ultraviolet communication systems by using a reflective plane. A channel model considering both scattering and reflection is proposed, and it is shown that the reflective plane can reduce the path loss and time delay, benefiting the design of high data-rate non-line-of-sight ultraviolet communication systems.
JOURNAL OF LIGHTWAVE TECHNOLOGY
(2022)
Article
Physics, Multidisciplinary
Bin Wang, Ming-Yang Zheng, Jin-Jian Han, Xin Huang, Xiu-Ping Xie, Feihu Xu, Qiang Zhang, Jian-Wei Pan
Summary: The research built an up-conversion single-photon detector with high temporal resolution and low noise count rate, demonstrating high-resolution and low-noise non-line-of-sight imaging technology successfully.
PHYSICAL REVIEW LETTERS
(2021)
Article
Engineering, Marine
Ying Liu, Yingmin Wang, Cheng Chen, Chenxi Liu
Summary: This paper proposes a practical and innovative algebraic solution for source localization in underwater sensor networks (UWSNs) in shallow seas. The proposed solution effectively addresses the challenges caused by sensor position errors and multipath effects, resulting in significantly improved positioning accuracy.
JOURNAL OF MARINE SCIENCE AND ENGINEERING
(2023)
Article
Computer Science, Software Engineering
Diego Royo, Jorge Garcia, Adolfo Munoz, Adrian Jarabo
Summary: This paper introduces a set of simple yet effective subpath sampling techniques for transient light transport simulation in occluded scenes. By analyzing the usual capture setups of non-line-of-sight (NLOS) scenes and leveraging the specific configuration, the integration path space is reduced. The research findings can be applied to range imaging, reflectance estimation, and other fields in transient light transport.
COMPUTERS & GRAPHICS-UK
(2022)
Article
Computer Science, Artificial Intelligence
Siyuan Shen, Zi Wang, Ping Liu, Zhengqing Pan, Ruiqian Li, Tian Gao, Shiying Li, Jingyi Yu
Summary: This paper presents a neural modeling framework for non-line-of-sight imaging, achieving state-of-the-art performance in experiments with synthetic and real datasets.
IEEE TRANSACTIONS ON PATTERN ANALYSIS AND MACHINE INTELLIGENCE
(2021)
Article
Optics
X. I. A. O. M. E. N. G. Zhou, J. I. A. N. Y. A. N. G. Shi, N. A. N. Chi, C. H. A. O. Shen, Z. I. W. E. I. LI
Summary: Visible light communication (VLC) is popular for indoor communication due to its high transmission speed and robustness against electromagnetic interference. This paper proposes a wavefront shaping method to enhance VLC in indoor scenarios with multiple users in line-of-sight (LOS) and non-line-of-sight (NLOS) paths. The method achieves significant improvement in light intensity and data rates for both LOS and NLOS links.
Article
Optics
Ruizhi Cao, Frederic de Goumoens, Baptiste Blochet, Jian Xu, Changhuei Yang
Summary: Non-line-of-sight (NLOS) imaging is a rapidly developing research direction with significant applications in autonomous vehicles, remote sensing, and other areas. This study introduces a method called UNCOVER focusing, which manipulates light to counter scattering and achieves NLOS imaging with unprecedented resolution. By actively focusing light onto hidden targets using wavefront shaping, the method forms a near diffraction-limited focus smaller than the object itself, enabling high-resolution imaging.
Article
Instruments & Instrumentation
Chrisy Sparling, Alice Ruget, Jonathan Leach, Dave Townsend
Summary: The inverse Abel transform is widely used in charged particle imaging, but it has limitations due to cylindrical symmetry constraints. This study shows how artificial neural networks can replace the inverse Abel transform and directly reconstruct 2D projections into 3D distributions.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Multidisciplinary Sciences
Abhinandan Bhattacharjee, Mritunjay K. Joshi, Suman Karan, Jonathan Leach, Anand K. Jha
Summary: This article investigates the behavior of entanglement in different continuous-variable bases and demonstrates the revival of entanglement in the angle-orbital angular momentum (OAM) bases during photon propagation.
Article
Chemistry, Analytical
Khaled Kassem, Piergiorgio Caramazza, Kevin J. Mitchell, Mitch Miller, Azadeh Emadi, Daniele Faccio
Summary: Researchers propose a wearable device that uses radar and haptic feedback technology to detect the movement of deaf-blind individuals in real time, providing potential assistance for multi-sensory impaired individuals in the future.
Article
Optics
Imogen Morland, Feng Zhu, Paul Dalgarno, Jonathan Leach
Summary: This study presents a technique for measuring target depth using non-linear optical methods with high precision on very small length scales. By utilizing statistical estimation theory and sCMOS camera data, it achieves approximately 30 nm depth precision for each pixel in 30 seconds.
Article
Chemistry, Analytical
Taylor Shields, Adetunmise C. Dada, Lennart Hirsch, Seungjin Yoon, Jonathan M. R. Weaver, Daniele Faccio, Lucia Caspani, Marco Peccianti, Matteo Clerici
Summary: The THz electro-optical sampling technique using single-photon detectors and squeezed vacuum field as the optical probe has been successfully demonstrated in experiments. The sensitivity of the field measurement is limited by the statistical properties of the probe state, which can be improved by using phase-locked single-photon detectors.
Article
Multidisciplinary Sciences
Stirling Scholes, German Mora-Martin, Feng Zhu, Istvan Gyongy, Phil Soan, Jonathan Leach
Summary: Single-Photon Avalanche Detector (SPAD) arrays are cutting-edge technology that can rapidly generate depth images with millimeter precision. They are crucial for autonomous systems as they provide guidance and situational awareness. This study establishes a numerical procedure to determine the depth imaging limits of SPAD arrays under real-world conditions, allowing for accurate and cost-effective performance evaluation without field testing. This procedure has applications in object detection, tracking, and imaging systems for various scenarios.
SCIENTIFIC REPORTS
(2023)
Article
Multidisciplinary Sciences
Alice Ruget, Max Tyler, German Mora Martin, Stirling Scholes, Feng Zhu, Istvan Gyongy, Brent Hearn, Steve McLaughlin, Abderrahim Halimi, Jonathan Leach
Summary: Single-photon-sensitive depth sensors have a growing application in human pose and gesture recognition in next-generation electronics. This study presents a temporal to spatial mapping to significantly enhance the resolution of a simple time-of-flight sensor. The developed explainable framework offers insight into how the network utilizes input data and relevant parameters.
Article
Optics
Stirling Scholes, Lehloa Mohapi, Jonathan Leach, Andrew Forbes, Angela Dudley
Summary: In this study, a Liquid Crystal on Silicon Spatial Light Modulator (LCoS-SLM) is used to imitate the mechanical design of a deformable mirror, and the effect of the number of mirror segments and their geometrical structure on resulting structured modes is quantitatively analysed. This approach can serve as a test bed prior to designing a deformable mirror for high power beam shaping.
APPLIED PHYSICS B-LASERS AND OPTICS
(2023)
Article
Optics
Mohamed Amir Alaa Belmekki, Jonathan Leach, Rachael Tobin, Gerald S. Buller, Stephen McLaughlin, Abderrahim Halimi
Summary: 3D single-photon LiDAR imaging is crucial for many applications, but requires analysis of low signal-to-noise ratio returns and high data volume. This paper proposes a multiscale approach for 3D surface detection, reducing data volume while obtaining background-free surfaces for depth and reflectivity inference. A hierarchical Bayesian model is also introduced for 3D reconstruction and spectral classification. Results demonstrate the superiority of these approaches compared to state-of-the-art algorithms.
Article
Physics, Multidisciplinary
Suraj Goel, Max Tyler, Feng Zhu, Saroch Leedumrongwatthanakun, Mehul Malik, Jonathan Leach
Summary: Efficient manipulation, sorting, and measurement of optical modes and single-photon states are achieved in this study. The researchers use a specially designed multiplane light converter to simultaneously and efficiently sort nonorthogonal, overlapping states of light encoded in the transverse spatial degree of freedom. This has implications for optimal image identification and classification in optical networks.
PHYSICAL REVIEW LETTERS
(2023)
Article
Chemistry, Analytical
Gyles E. Cozier, Rachael C. Andrews, Anca Frinculescu, Ranjeet Kumar, Benedict May, Tom Tooth, Peter Collins, Andrew Costello, Tom S. F. Haines, Tom P. Freeman, Ian S. Blagbrough, Jennifer Scott, Trevor Shine, Oliver B. Sutcliffe, Stephen M. Husbands, Jonathan Leach, Richard W. Bowman, Christopher R. Pudney
Summary: Synthetic cannabinoids (SCs) are a class of new psychoactive substances (NPS) primarily used in prisons and homeless communities in the U.K. SCs have severe side effects and are associated with numerous deaths. The detection of SCs is challenging due to their chemical diversity and their adsorption onto physical matrices. This study presents a portable and rapid generic test for SCs using fluorescence analysis.
ANALYTICAL CHEMISTRY
(2023)
Review
Optics
Robert h. Hadfield, Jonathan Leach, Fiona Fleming, Douglas j. Paul, Chee hing Tan, Jo shien Ng, Robert k. Henderson, Gerald s. Buller
Summary: The development of single-photon detectors with picosecond timing resolution has driven progress in time-correlated single-photon counting applications, including quantum optics, life sciences, and remote sensing. Advanced optoelectronic device architectures offer high-performance single-pixel devices and the ability to scale up to detector arrays, increasing single-photon sensitivity.
Article
Optics
German Mora-Martin, Stirling Scholes, Lice Ruget, Robert Henderson, Jonathan Leach, Istvan Gyongy
Summary: In this paper, a 3D convolutional neural network (CNN) is trained using synthetic depth sequences to denoise and upscale (x4) depth data. Experimental results using synthetic and real ToF data demonstrate the effectiveness of the approach. With GPU acceleration, the approach achieves processing speeds of >30 frames per second, making it suitable for low-latency imaging.
Article
Quantum Science & Technology
Chane Moodley, Alice Ruget, Jonathan Leach, Andrew Forbes
Summary: In order to improve image acquisition speed, researchers implemented four machine learning algorithms and trained them on a dataset with noise and blur. The results showed that logistic regression algorithm achieved a 10x speed up in image acquisition time with a prediction accuracy of 99%. This method does not require image denoising or enhancement prior to recognition, reducing training and implementation time, as well as computational intensity, making it suitable for real-time quantum imaging and recognition of light sensitive structures.
ADVANCED QUANTUM TECHNOLOGIES
(2023)
Article
Optics
Imogen Morland, Hanna Ostapenko, Feng Zhu, Derryck T. Reid, Jonathan Leach
Summary: In this study, correlated photon pairs were generated at 790nm wavelength using a compact GHz-rate cavity laser. The indistinguishability of the photons produced by SPDC was verified using Hong-Ou-Mandel interferometry, and a dip in coincidence counts with a visibility of 81.8% was observed.
