Wavefront sensing is a set of techniques providing efficient means to ascertain the shape of an optical wavefront or its deviation from an ideal reference. Owing to its wide dynamical range and high optical efficiency, the Shack-Hartmann wavefront sensor is nowadays the most widely used of these sensors. Here we show that it actually performs a simultaneous measurement of position and angular spectrum of the incident radiation and, therefore, when combined with tomographic techniques previously developed for quantum information processing, the Shack-Hartmann wavefront sensor can be instrumental in reconstructing the complete coherence properties of the signal. We confirm these predictions with an experimental characterization of partially coherent vortex beams, a case that cannot be treated with the standard tools. This seems to indicate that classical methods employed hitherto do not fully exploit the potential of the registered data.
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http://dx.doi.org/10.1038/ncomms4275 | DOI Listing |
Sensors (Basel)
January 2025
Free-Space Optical Communication Technology Research Center, Harbin Institute of Technology, Harbin 150001, China.
To achieve real-time deep learning wavefront sensing (DLWFS) of dynamic random wavefront distortions induced by atmospheric turbulence, this study proposes an enhanced wavefront sensing neural network (WFSNet) based on convolutional neural networks (CNN). We introduce a novel multi-objective neural architecture search (MNAS) method designed to attain Pareto optimality in terms of error and floating-point operations (FLOPs) for the WFSNet. Utilizing EfficientNet-B0 prototypes, we propose a WFSNet with enhanced neural architecture which significantly reduces computational costs by 80% while improving wavefront sensing accuracy by 22%.
View Article and Find Full Text PDFComput Biol Med
January 2025
Centre of Physics of the Universities of Minho and Porto, University of Minho, 4710-057, Braga, Portugal. Electronic address:
The purpose of this study was to use wavefront sensing as an objective method to detect and assess dynamic accommodation in subjects with accommodative dysfunctions and symptoms related to near-vision tasks. Sixty-three subjects were divided into control (N = 18), symptomatic without any accommodative dysfunction (SWD) (N = 18), infacility of accommodation (INFA) (N = 6), excess of accommodation (EA) (N = 9), and insufficiency of accommodation (INSA) (N = 12) groups. Accommodation was stimulated in different cycles of accommodation and disaccommodation while ocular aberrations were measured.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Mechanical Engineering, University of California at Riverside, Riverside, California 92521, United States.
Sensing light's polarization and wavefront direction enables surface curvature assessment, material identification, shadow differentiation, and improved image quality in turbid environments. Traditional polarization cameras utilize multiple sensor measurements per pixel and polarization-filtering optics, which result in reduced image resolution. We propose a nanophotonic pipeline that enables compressive sensing and reduces the sampling requirements with a low-refractive-index, self-assembled optical encoder.
View Article and Find Full Text PDFQuantum backflow (QB), a counterintuitive interference phenomenon where particles with positive momentum can propagate backward, is important in applications involving light-matter interactions. To date, experimental demonstrations of backflow have been restricted to classical optical systems using techniques such as slit scanning or Shack-Hartmann wavefront sensing, which suffer from low spatial resolution due to the inherent limitations in slit width and lenslet array density. Here, we report an observation of azimuthal backflow (AB) both theoretically and experimentally by employing the weak measurement technique, which enables the precise extraction of photon momentum at each pixel.
View Article and Find Full Text PDFACS Nano
January 2025
Department of Mechanical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Optical metasurfaces, arrays of nanostructures engineered to manipulate light, have emerged as a transformative technology in both research and industry due to their compact design and exceptional light control capabilities. Their strong light-matter interactions enable precise wavefront modulation, polarization control, and significant near-field enhancements. These unique properties have recently driven their application in biomedical fields.
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