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Soil is a scattering medium that inhibits imaging of plant-microbial-mineral interactions that are essential to plant health and soil carbon sequestration. However, optical imaging in the complex medium of soil has been stymied by the seemingly intractable problems of scattering and contrast. Here, we develop a wavefront shaping method based on adaptive stochastic parallel gradient descent optimization with a Hadamard basis to focus light through soil mineral samples. Our approach allows a sparse representation of the wavefront with reduced dimensionality for the optimization. We further divide the used Hadamard basis set into subsets and optimize a certain subset at once. Simulation and experimental optimization results demonstrate our method has an approximately seven times higher convergence rate and overall better performance compared to that with optimizing all pixels at once. The proposed method can benefit other high-dimensional optimization problems in adaptive optics and wavefront shaping.
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http://dx.doi.org/10.1364/AO.442957 | DOI Listing |
Nanophotonics
August 2025
Department of Electronic Engineering, Hanyang University, Seoul, 04763, Republic of Korea.
Under-display camera (UDC) systems enable full-screen displays in smartphones by embedding the camera beneath the display panel, eliminating the need for notches or punch holes. However, the periodic pixel structures of display panels introduce significant optical diffraction effects, leading to imaging artifacts and degraded visual quality. Conventional approaches to mitigate these distortions, such as deep learning-based image reconstruction, are often computationally expensive and unsuitable for real-time applications in consumer electronics.
View Article and Find Full Text PDFControlling light to multiple focal locations through complex scattering media is becoming increasingly significant in various realms. Although wavefront shaping (WFS) has been demonstrated as a promising solution to counteracting optical scattering, current WFS methods for multifocal control through scattering media suffer from low focal quality, extensive measurements, or complexity of system configurations and signal reconstructions. Here, we report a WFS concept, called binary-intensity-synthetic digital optical phase conjugation (BIS-DOPC), to mitigate these drawbacks.
View Article and Find Full Text PDFSci Rep
August 2025
Photonics Research Laboratory, Center of Excellence on Applied Electromagnetic Systems, School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran, Iran.
In order to focus light at a desired depth, wavefront shaping of the incident light is required. Light focusing is used in applications such as medical imaging, sensing, power dividers, etc. For this purpose, various phase plates can be exploited, but we propose a periodic phase plate.
View Article and Find Full Text PDFNat Commun
August 2025
Department of Electrical and Computer Engineering, Princeton University, Princeton, NJ, USA.
The line-of-sight blockage is one of the main challenges in sub-terahertz wireless networks. Interestingly, the extended near-field range of sub-terahertz nodes gives rise to near-field wavefront shaping as a feasible remedy to tackle this issue. Recently, Airy beams emerged as one promising solution that opens significant opportunities to circumvent blockers with unique self-accelerating properties and curved trajectories.
View Article and Find Full Text PDFMetaoptics are thin, planar surfaces consisting of many subwavelength optical resonators that can be designed to simultaneously control the amplitude, phase, and polarization to arbitrarily shape an optical wavefront much in the same manner as a traditional lens but with a much smaller form factor. Incorporation of metaoptics into a conventional optical system spans multiple length scales between that of the individual metaoptic elements (<λ) and that of the entire size of the optic (≫λ), making computational techniques that accurately simulate the optical response of metaoptics computationally intractable, while more efficient techniques utilizing various approximations suffer from inaccuracies in their prediction of the optical response. To overcome the trade-off between speed and accuracy, we implement a transformer-based neural network solver to calculate the optical response of metaoptics and combine it with commercial ray optics software incorporating Fourier propagation methods to simulate an entire optical system.
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