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Related papers: Diffraction manipulation by four-wave mixing

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Diffusion models have shown remarkable success across a wide range of generative tasks. However, they often suffer from spatially inconsistent generation, arguably due to the inherent locality of their denoising mechanisms. This can yield…

Machine Learning · Computer Science 2026-02-04 Wenshuai Zhao , Zhiyuan Li , Yi Zhao , Mohammad Hassan Vali , Martin Trapp , Joni Pajarinen , Juho Kannala , Arno Solin

Deviations from the perfect atomic arrangements in crystals play an important role in affecting their properties. Similarly, diffusion of such deviations is behind many microstructural changes in solids. However, observation of point defect…

Materials Science · Physics 2014-07-28 Jani Kotakoski , Clemens Mangler , Jannik C. Meyer

Adaptive optics in combination with multi-photon techniques is a powerful approach to image deep into a specimen. Remarkably, virtually all adaptive optics schemes today rely on wavefront modulators which are reflective, diffractive, or…

Metagratings have been shown to form an agile and efficient platform for extreme wavefront manipulation, going beyond the limitations of gradient metasurfaces. Previous approaches for transmissive metagratings have resorted on compound…

We introduce a class of variational wavefunctions that capture the long-range interaction between neutral systems (atoms and molecules) without changing the diagonal of the density matrix of each monomer. The corresponding energy…

Chemical Physics · Physics 2019-03-26 Derk P. Kooi , Paola Gori-Giorgi

We consider image denoising using a nonlinear diffusion process, where we solve unsteady partial differential equations with nonlinear coefficients. The noised image is given as an initial condition, and nonlinear coefficients are used to…

Numerical Analysis · Mathematics 2025-05-14 Maria Vasilyeva , Aleksei Krasnikov , Kelum Gajamannage , Mehrube Mehrubeoglu

Diffusion models are capable of generating impressive images conditioned on text descriptions, and extensions of these models allow users to edit images at a relatively coarse scale. However, the ability to precisely edit the layout,…

Computer Vision and Pattern Recognition · Computer Science 2024-02-01 Daniel Geng , Andrew Owens

An optical field will undergo coherent diffusion when it is mapped into thermal-motioned atoms, e.g., in a slow or storage light process. As was demonstrated before, such diffusion effect is equivalent to a spatial low-pass filter…

Quantum Physics · Physics 2022-07-15 Yun Chen , Chengyuan Wang , Zibin Jiang , Wei Zhang , Zehao Shen , Hong Gao , Fuli Li

Super-resolution imaging using sub-diffraction field localization by micron sized transparent beads (microspheres) was recently demonstrated [1]. Practical applications in microscopy require control over the positioning of the microspheres.…

Optics · Physics 2013-12-25 Leonid A. Krivitsky , Jia Jun Wang , Zengbo Wang , Boris Lukiyanchuk

We develop a model to calculate nonlinear polarization in a nondegenerate four-wave mixing in diamond configuration which includes the effects of hyperfine structure and Doppler broadening. We verify the model against the experiment with…

Atomic Physics · Physics 2015-02-24 Michał Parniak , Wojciech Wasilewski

We theoretically describe the quasi one-dimensional transverse spreading of a light pulse propagating in a nonlinear optical material in the presence of a uniform background light intensity. For short propagation distances the pulse can be…

Pattern Formation and Solitons · Physics 2019-07-30 M. Isoard , A. M. Kamchatnov , N. Pavloff

Low-light photography produces images with low signal-to-noise ratios due to limited photons. In such conditions, common approximations like the Gaussian noise model fall short, and many denoising techniques fail to remove noise…

Computer Vision and Pattern Recognition · Computer Science 2025-07-08 Liying Lu , Raphaël Achddou , Sabine Süsstrunk

The nonlinear optical response of materials is the foundation upon which applications such as frequency conversion, all-optical signal processing, molecular spectroscopy, and nonlinear microscopy are built. However, the utility of all such…

The reorientational nonlinearity of nematic liquid crystals enables a self-localized spatial soliton and its waveguide to be deflected or destroyed by a control beam propagating across the cell. We demonstrate a simple all-optical…

Exciting electrons in solids with intense light pulses offers the possibility of generating new states of matter through nonthermal means and controlling their macroscopic properties on femto- to picosecond timescales. One way to manipulate…

Materials Science · Physics 2021-10-07 Alfred Zong , Anshul Kogar , Nuh Gedik

We propose an efficient method for spatial filtering of light beams by propagating them through 2D (also 3D) longitudinally chirped photonic crystals, i.e. through the photonic structures with fixed transverse lattice period and with the…

Optics · Physics 2015-05-13 Kestutis Staliunas , Victor J. Sanchez-Morcillo

We propose a time-domain boundary integral method to model linear wave propagation with refractive, focusing, and Doppler effects arising from medium heterogeneities and moving obstacles. In contrast to existing techniques, our method…

Numerical Analysis · Mathematics 2026-05-13 Raaghav Ramani

We employ ptychography, a phase-retrieval imaging technique, to show experimentally for the first time that a partially coherent high-energy matter (electron) wave emanating from an extended source can be decomposed into a set of mutually…

Mesoscale and Nanoscale Physics · Physics 2017-01-04 S. Cao , P. Kok , P. Li , A. M. Maiden , J. M. Rodenburg

Spatial filtering is an important mechanism to improve the spatial quality of laser beams. Typically, a confocal arrangement of lenses with a diaphragm in the focal plane is used for intracavity spatial filtering. Such conventional…

Quantum simulations with ultracold atoms typically create atomic wavefunctions with structures at optical length scales, where direct imaging suffers from the diffraction limit. In analogy to advances in optical microscopy for biological…

Quantum Gases · Physics 2019-04-10 Sarthak Subhankar , Yang Wang , Tsz-Chun Tsui , Steven L. Rolston , James V. Porto