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Related papers: Bessel Speckles

200 papers

Random optical fields with two widely different correlation lengths generate far field speckle spots that are themselves highly speckled. We call such patterns speckled speckle, and study their critical points (singularities and stationary…

Optics · Physics 2009-11-13 Isaac Freund , David A. Kessler

This work introduces the causal bootstrap, a framework for bounding smeared spectral observables from finite non-perturbative Euclidean data. The method optimizes over the convex set of positive spectral densities compatible with the data…

High Energy Physics - Lattice · Physics 2026-05-21 Ryan Abbott , Sarah Fields , William I. Jay , Patrick Oare , Matteo Saccardi

We present a ring aperture with independently switchable segments for the three-dimensional control of quasi propagation invariant beams. We demonstrate that our liquid crystal design concept preserves coherence and generates the Bessel…

Optics · Physics 2016-10-10 Angelina Müller , Matthias C. Wapler , Ulrike Wallrabe

We developed a Bessel-beam photoacoustic microscopical simulation platform by using the k-Wave: MATLAB toolbox. The simulation platform uses the ring slit method to generate Bessel beam. By controlling the inner and outer radius of the ring…

Medical Physics · Physics 2020-09-23 Xianlin Song , Jianshuang Wei , Lingfang Song

Elastic light scattering has been extensively used to study samples showing a non uniform refraction index on lengthscales from a fraction of a micrometer to a fraction of a millimeter. Typically, a wide laser beam is sent through the…

Optics · Physics 2009-07-21 Doriano Brogioli

Imaging through scattering is an important, yet challenging problem. Tremendous progress has been made by exploiting the deterministic input-output "transmission matrix" for a fixed medium. However, this "one-to-one" mapping is highly…

Image and Video Processing · Electrical Eng. & Systems 2018-09-27 Yunzhe Li , Yujia Xue , Lei Tian

Several image pattern recognition tasks rely on superpixel generation as a fundamental step. Image analysis based on superpixels facilitates domain-specific applications, also speeding up the overall processing time of the task. Recent…

Computer Vision and Pattern Recognition · Computer Science 2018-02-19 Marcelo Santos , Luciano Oliveira

Sensor noise sources cause differences in the signal recorded across pixels in a single image and across multiple images. This paper presents a Bayesian approach to decomposing and characterizing the sensor noise sources involved in imaging…

Modeling the distribution of natural images is a landmark problem in unsupervised learning. This task requires an image model that is at once expressive, tractable and scalable. We present a deep neural network that sequentially predicts…

Computer Vision and Pattern Recognition · Computer Science 2016-08-22 Aaron van den Oord , Nal Kalchbrenner , Koray Kavukcuoglu

The scattering of coherent X-rays from dynamically evolving systems is currently becoming experimentally feasible. The scattered beam produces a pattern of bright and dark speckles, which fluctuate almost independently in time and can be…

Condensed Matter · Physics 2015-06-25 Gregory Brown , Per Arne Rikvold , Martin Grant

(abridged) Imaging observations are generally affected by a fluctuating background of speckles, a particular problem when detecting faint stellar companions at small angular separations. Knowing the distribution of the speckle intensities…

Astrophysics · Physics 2009-11-13 Michael P. Fitzgerald , James R. Graham

Speckle patterns are ubiquitous in optics and have multiple applications for which the control of their spatial correlations is essential. Here, we report on a method to engineer speckle correlations behind a scattering medium through the…

Ultrasound imaging is widely used for real-time, noninvasive diagnosis, but speckle and related artifacts reduce image quality and can hinder interpretation. We present a diffusion-based ultrasound despeckling method built on the Image…

Computer Vision and Pattern Recognition · Computer Science 2026-02-27 Shuoqi Chen , Yujia Wu , Geoffrey P. Luke

The existing research on spectral algorithms, applied within a Reproducing Kernel Hilbert Space (RKHS), has primarily focused on general kernel functions, often neglecting the inherent structure of the input feature space. Our paper…

Machine Learning · Statistics 2024-03-08 Weichun Xia , Lei Shi

The study of astrophysical plasma lensing, such as in the case of extreme scattering events, has typically been conducted using the geometric limit of optics, neglecting wave effects. However, for the lensing of coherent sources such as…

High Energy Astrophysical Phenomena · Physics 2021-10-15 Dylan L. Jow , Fang Xi Lin , Emily Tyhurst , Ue-Li Pen

We generate conical second-harmonic radiation by transverse excitation of a two-dimensional annular periodically-poled nonlinear photonic structure with a fundamental Gaussian beam. We show that these conical waves are the far-field images…

Pattern Formation and Solitons · Physics 2009-11-13 Solomon M. Saltiel , Dragomir N. Neshev , Robert Fischer , Wieslaw Krolikowski , Ady Arie , Yuri S. Kivshar

In this paper we address the uncertainty issues involved in the low-level vision task of image segmentation. Researchers in computer vision have worked extensively on this problem, in which the goal is to partition (or segment) an image…

Artificial Intelligence · Computer Science 2013-03-08 Steven M. LaValle , Seth A. Hutchinson

Correlated states of light, both classical and quantum, can find useful applications in the implementation of several imaging techniques. Among the employed sources, pseudo-thermal states, generated by the passage of a laser beam through a…

Quantum Physics · Physics 2024-03-18 Silvia Cassina , Gabriele Cenedese , Alessia Allevi , Maria Bondani

Even though image signals are typically acquired on a regular two dimensional grid, there exist many scenarios where non-regular sampling is possible. Non-regular sampling can remove aliasing. In terms of the non-regular sampling patterns,…

Image and Video Processing · Electrical Eng. & Systems 2022-03-02 Simon Grosche , Jürgen Seiler , André Kaup

We introduce Biphoton Entanglement Light Spectroscopy (BELS), a quantum spectroscopic technique that employs polarization entangled Bell pairs and two photon interference to probe material properties. In BELS, the measured signal arises not…

Quantum Physics · Physics 2026-03-25 V. V. Desai , N. P. Armitage