This paper reviews the state of the art of single-photon avalanche diode (SPAD) image sensors for time-resolved imaging. The focus of the paper is on pixel architectures featuring small pixel size (<25 μm) and high fill factor (>20%) as a key enabling technology for the successful implementation of high spatial resolution SPAD-based image sensors. A summary of the main CMOS SPAD implementations, their characteristics and integration challenges, is provided from the perspective of targeting large pixel arrays, where one of the key drivers is the spatial uniformity. The main analog techniques aimed at time-gated photon counting and photon timestamping suitable for compact and low-power pixels are critically discussed. The main features of these solutions are the adoption of analog counting techniques and time-to-analog conversion, in NMOS-only pixels. Reliable quantum-limited single-photon counting, self-referenced analog-to-digital conversion, time gating down to 0.75 ns and timestamping with 368 ps jitter are achieved.
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http://dx.doi.org/10.3390/s16050745 | DOI Listing |
Sci Rep
December 2024
School of Electronics Engineering, Vellore Institute of Technology, Vellore, India.
Autonomous vehicles, often known as self-driving cars, have emerged as a disruptive technology with the promise of safer, more efficient, and convenient transportation. The existing works provide achievable results but lack effective solutions, as accumulation on roads can obscure lane markings and traffic signs, making it difficult for the self-driving car to navigate safely. Heavy rain, snow, fog, or dust storms can severely limit the car's sensors' ability to detect obstacles, pedestrians, and other vehicles, which pose potential safety risks.
View Article and Find Full Text PDFComput Biol Med
December 2024
Complex Systems Laboratory, University Politehnica of Bucharest, Bucharest, Romania; Centre for Elderly and Nursing Home Medicine, University of Bergen, Bergen, Norway; Neuro-SysMed Center, University of Bergen, Bergen, Norway. Electronic address:
Heart rate response to physical activity is widely investigated in clinical and training practice, as it provides information on a person's physical state. For emerging digital phenotyping approaches, there is a need for individualized model estimation. In this study, we propose a zero-poles model and a data-driven evolutionary learning method for identification.
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December 2024
School of Electrical and Electronic Engineering, Nanyang Technological University, 639798, Singapore, Singapore.
The outstanding performance of superconducting nanowire single-photon detectors (SNSPDs) has expanded their application areas from quantum technologies to astronomy, space communication, imaging, and LiDAR. As a result, there has been a surge in demand for these devices, that commercial products cannot readily meet. Consequently, more research and development efforts are being directed towards establishing in-house SNSPD manufacturing, leveraging existing nano-fabrication capabilities that can be customized and fine-tuned for specific needs.
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December 2024
Physical Research Laboratory, Ahmedabad, Gujarat, 380009, India.
Talbot length, the distance between two consecutive self-image planes along the propagation axis for a periodic diffraction object (grating) illuminated by a plane wave, depends on the period of the object and the wavelength of illumination. This property makes the Talbot effect a straightforward technique for measuring the period of a periodic object (grating) by accurately determining the Talbot length for a given illumination wavelength. However, since the Talbot length scale is proportional to the square of the grating period, traditional Talbot techniques face challenges when dealing with smaller grating periods and minor changes in the grating period.
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December 2024
Advanced Research and Innovation Center (ARIC), Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates.
The fourth industrial revolution witnessed significant advancements in automating numerous aircraft inspection tasks. Still, certain critical procedures continue to rely on manual execution, including the aero-engine blade weighing process. This task is of paramount importance for blade mass inspection and engine dynamic balancing.
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