Optical interferometry enables distance measurement with record-high precision. However, the conventional interference intensity shows fast spatial variations, limiting photodetection to a single spot. The light intensity at this spot is affected by various noises, restricting the signal-to-noise ratio (SNR) of a coherent system. Here, we generate uniform interference patterns based on zero-index metawaveguides, enabling the photodetection of spatially extended intensity through multiple-pixel measurements of a charge-coupled device. Averaging the intensities measured across multiple pixels cancels uncorrelated noise, significantly improving the SNR and allowing the detection of weakly reflected optical power. Experiments show that nanoscale displacements down to 26 nm (/59) can be converted into high-contrast intensity changes over a macroscopic area, leading to an SNR 10+ times higher (11.68 dB) than that of conventional single-spot photodetection. Our nanophotonic zero-index platform can be implemented in any coherent system, possibly leading to a transformative impact in precise measurement of the distance, profile, and spectrum.
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http://dx.doi.org/10.1021/acs.nanolett.4c06421 | DOI Listing |
Jpn J Radiol
March 2025
Department of Radiology, Mie University Graduate School of Medicine, 2-174 Edobashi, Tsu, Mie, 514-8507, Japan.
Purpose: Myocardial computed tomography (CT) late enhancement (LE) allows assessment of myocardial scarring. Super-resolution deep learning image reconstruction (SR-DLR) trained on data acquired from ultra-high-resolution CT may improve image quality for CT-LE. Therefore, this study investigated image noise and image quality with SR-DLR compared with conventional DLR (C-DLR) and hybrid iterative reconstruction (hybrid IR).
View Article and Find Full Text PDFGround Water
March 2025
Department of Civil Engineering, MVGR College of Engineering, Vizianagaram, India.
Transient hydraulic tomography (THT) is proven to be effective in representing hydraulic and storage properties in diverse hydrogeologic settings. Sequential inversion of THT is computationally efficient, however, its accuracy is constrained by the number and sequence of pumping datasets used in the inversion. While signal-to-noise ratio (SNR) is commonly used to regulate the order of pumping datasets, it often disregards the information content.
View Article and Find Full Text PDFCan Assoc Radiol J
March 2025
Department of Radiology, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
This study investigates the impact of deep learning-based contrast boosting (DL-CB) on image quality and measurement reliability in low-contrast media (low-CM) CT for pre-transcatheter aortic valve replacement (TAVR) assessment. This retrospective study included TAVR candidates with renal dysfunction who underwent low-CM (30-mL: 15-mL bolus of contrast followed by 50-mL of 30% iomeprol solution) pre-TAVR CT between April and December 2023, along with matched standard-CM controls (n = 68). Low-CM images were reconstructed as conventional, 50-keV, and DL-CB images.
View Article and Find Full Text PDFGlob Chall
March 2025
Faculty of Computer and Informatics Engineering, Computer Engineering Department Istanbul Technical University Istanbul 34469 Turkey.
Advancements in electronic textiles over the past decade have significantly transformed the field of wearable technology, with recent developments leading to the production of a wide array of textile-based sensing and actuation systems. Beyond sensors and actuators, textile-based technologies can benefit from the integration of additional electronic solutions within the framework of textilization. One such solution is filtering, which has primarily been explored in the context of high-frequency applications in e-textiles.
View Article and Find Full Text PDFJ Biomed Opt
March 2025
University of Minnesota, Department of Biomedical Engineering, Minneapolis, Minnesota, United States.
Significance: We introduce a visible-light polarization-sensitive optical coherence tomography (PS-OCT) system that operates in the spectral domain with balanced detection (BD) capability. While the BD improves the signal-to-noise ratio (SNR), the use of shorter wavelengths improves spatial resolution and birefringence sensitivity.
Aim: We aim to implement a new optical design, characterize its performance, and investigate the imaging potential for biological tissues.
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