English
Related papers

Related papers: Diffraction manipulation by four-wave mixing

200 papers

We report the experimental demonstration of the superluminal propagation of multi-spatial-mode images via four-wave mixing in hot atomic vapor, in which all spatial sub-regions propagate with negative group velocities. We investigate the…

Quantum Physics · Physics 2012-06-06 Ryan T. Glasser , Ulrich Vogl , Paul D. Lett

Solitons are localized nonlinear wave packets that propagate without spreading because nonlinearity balances dispersion. Their robustness is well understood in effectively one-dimensional systems, but introducing additional spatial…

In recent years, a great deal of emphasis has been placed on achieving the diffraction limit with large aperture telescopes. For a well matched focal-plane instrument, the diffraction limit provides the highest possible angular resolution…

Astrophysics · Physics 2009-11-11 J. Bland-Hawthorn , A. Horton

Diffusion models, which learn to reverse a signal destruction process to generate new data, typically require the signal at each step to have the same dimension. We argue that, considering the spatial redundancy in image signals, there is…

Machine Learning · Computer Science 2022-11-30 Han Zhang , Ruili Feng , Zhantao Yang , Lianghua Huang , Yu Liu , Yifei Zhang , Yujun Shen , Deli Zhao , Jingren Zhou , Fan Cheng

Matter-wave optics is often viewed as a linear analogue of photonics, where noninteracting particles are coherently split, diffracted, and recombined, and interference arises from single-particle coherence. In ultracold quantum gases,…

Quantum Gases · Physics 2025-11-18 RuGway Wu , Maximilian Prüfer , Jörg Schmiedmayer

A simple physical mechanism of stimulated light scattering on nanoscale objects in water suspension similar to Langmuir waves mechanism in plasma is proposed. The proposed mechanism is based on a dipole interaction between the light wave…

The diffraction of electromagnetic plane waves by a rectangular grating formed by discrete steps in the interface of a homogeneous, isotropic, linear, negative phase--velocity (negative index) material with free space is studied using the…

Optics · Physics 2009-11-11 Ricardo A. Depine , Akhlesh Lakhtakia , David R. Smith

Discrete element method simulations of confined bidisperse granular shear flows elucidate the balance between diffusion and segregation that can lead to either mixed or segregated states, depending on confining pressure. Results indicate…

Soft Condensed Matter · Physics 2018-09-24 Alexander M. Fry , Paul B. Umbanhowar , Julio M. Ottino , Richard M. Lueptow

We experimentally probe complex bio-photonic architecture of microstructures on the transparent insect wings by a simple, non-invasive, real time optical technique. A stable and reproducible far-field diffraction pattern in transmission was…

We describe a time-resolved monitoring technique for heterogeneous media. Our approach is based on the spatial variations of the cross-coherence of coda waveforms acquired at fixed positions but at different dates. To locate and…

Data Analysis, Statistics and Probability · Physics 2015-05-19 Vincent Rossetto , Ludovic Margerin , Thomas Planès , Éric Larose

Currently, applying diffusion models in pixel space of high resolution images is difficult. Instead, existing approaches focus on diffusion in lower dimensional spaces (latent diffusion), or have multiple super-resolution levels of…

Computer Vision and Pattern Recognition · Computer Science 2023-12-13 Emiel Hoogeboom , Jonathan Heek , Tim Salimans

Pixel size in cameras and other refractive imaging devices is typically limited by the free-space diffraction. However, a vast majority of semiconductor-based detectors are based on materials with substantially high refractive index. We…

Optics · Physics 2018-03-28 Bo Fan , Sandeep Inampudi , Viktor A. Podolskiy

We introduce a framework for scalable and broadband free-space phase-matched four-wave mixing in ring resonators. This method for four-wave mixing reduces the complexity of coupling an emitter to a quantum network by combining the spatial…

We present a parameter-decoupled superresolution framework for estimating sub-wavelength separations of passive two-point sources without requiring prior knowledge or control of the source. Our theoretical foundation circumvents the need to…

We address the properties of surface solitons supported by optical lattices imprinted in photorefractive media with asymmetric diffusion nonlinearity. Such solitons exist only in finite gaps of lattice spectrum. In contrast to latticeless…

Optics · Physics 2009-11-13 Yaroslav V. Kartashov , Victor A. Vysloukh , Lluis Torner

Point Spread Function (PSF) for imaging through inhomogeneous refractive medium, such as atmospheric turbulence is bounded by three constraints [Charnotskii, Opt. Eng., 52, 04600, (2013)]. PSF is non-negative, band-limited, and the third…

Optics · Physics 2022-07-06 Mikhail Charnotskii

A method is presented for generation of a subwavelength (0.43 lambda) longitudinally polarized beam, which propagates without divergence over lengths of about 4 lambda in free space. This is achieved by controlling the amplitude, phase and…

Popular Physics · Physics 2007-09-19 Haifeng Wang , L. P. Shi , B. S. Luk`yanchuk , C. J. R. Sheppard , T. C. Chong , G. Q. Yuan

Many adaptive optics systems operate by measuring the distortion of the wavefront in one wavelength range and performing the scientific observations in a second, different wavelength range. One common technique is to measure wavefront…

Astrophysics · Physics 2009-11-07 Henry G. Roe

The quantum wave nature of matter is a cornerstone of modern physics, which has been demonstrated for a wide range of fundamental and composite particles. While diffraction at nanomechanical masks is usually regarded to be independent of…

We control the diffusion of light in a disordered photonic waveguide by modulating the waveguide geometry. In a single waveguide of varying cross-section, the diffusion coefficient changes spatially in two dimensions due to localization…

Optics · Physics 2014-07-30 Raktim Sarma , Timofey Golubev , Alexey Yamilov , Hui Cao
‹ Prev 1 3 4 5 6 7 10 Next ›