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This paper presents a digital interferometric method to demodulate Placido fringe patterns. This method uses a computer-stored conic-wavefront as reference carrier. Even though, Placido mires are widely used in corneal topographers. This is…

Optics · Physics 2012-04-18 Manuel Servin

Precise modeling of extended sources is a central challenge in modern optical engineering, laser physics, and computational lithography. Unlike ideal point sources or completely incoherent thermal radiation sources, real-world light sources…

Optics · Physics 2025-12-09 Rongqi Shang , Donglin Ma

We propose a number of variational regularisation methods for the estimation and decomposition of motion fields on the $2$-sphere. While motion estimation is based on the optical flow equation, the presented decomposition models are…

Optimization and Control · Mathematics 2014-03-05 Clemens Kirisits , Lukas F. Lang , Otmar Scherzer

Direct imaging of exoplanets requires very high contrast levels, which are obtained using coronagraphs. But residual quasi-static aberrations create speckles in the focal plane downstream of the coronagraph which mask the planet. This…

Instrumentation and Methods for Astrophysics · Physics 2015-06-16 J. Mazoyer , P. Baudoz , R. Galicher , M. Mas , G. Rousset

Imaging faint objects, such as exoplanets or disks, around nearby stars is extremely challenging because host star images are dominated by the telescope diffraction pattern. Using a coronagraph is an efficient solution for removing…

For the simulation of anisoplanatic optical turbulence, split-step propagation is the gold standard. Within the context of the degradations being limited to phase distortions, one instead may focus on generating the phase realizations…

Optics · Physics 2023-05-17 Nicholas Chimitt , Stanley H. Chan

In space-based gravitational wave detection, the estimation of far-field wavefront error of the distorted beam is the precondition for the noise reduction. Zernike polynomials is used to describe the wavefront error of the transmitted…

Instrumentation and Methods for Astrophysics · Physics 2023-02-08 Ya-Zheng Tao , Hong-Bo Jin , Yue-Liang Wu

We discuss computing with hierarchies of families of (potentially weighted) semiclassical Jacobi polynomials which arise in the construction of multivariate orthogonal polynomials. In particular, we outline how to build connection and…

Numerical Analysis · Mathematics 2024-07-11 Ioannis P. A. Papadopoulos , Timon S. Gutleb , Richard M. Slevinsky , Sheehan Olver

Analysis of the imaging of some simple distributions of object phase by a phase plate of Zernike type shows that sharp transitions in the object phase are well transmitted. The low-frequency components of the complete object function are…

Instrumentation and Detectors · Physics 2013-07-26 C. J. Edgcombe

Nowadays, pre-trained encoders are widely used in medical image segmentation due to their strong capability in extracting rich and generalized feature representations. However, existing methods often fail to fully leverage these features,…

Computer Vision and Pattern Recognition · Computer Science 2025-07-29 Xiaolin Gou , Chuanlin Liao , Jizhe Zhou , Fengshuo Ye , Yi Lin

In this paper we develop a plane wave type method for discretization of homogeneous Helmholtz equations with variable wave numbers. In the proposed method, local basis functions (on each element) are constructed by the geometric optics…

Numerical Analysis · Mathematics 2021-07-22 Qiya Hu , Zezhong Wang

In this work, a numerical modal decomposition approach is applied to model the optical field of laser light after propagating through a highly multi-mode fiber. The algorithm for the decomposition is based on the reconstruction of measured…

Optics · Physics 2020-10-20 Hao Pang , Tobias Haecker , Alexandre Bense , Tobias Haist , Daniel Flamm

This paper presents the basic principle and theoretical relationships of an original method allowing to retrieve the Wavefront Errors (WFE) of a ground or space-borne telescope when combining its main pupil with a second, decentered…

Optics · Physics 2011-05-19 Francois Henault

Microlocal analysis provides deep insight into singularity structures and is often crucial for solving inverse problems, predominately, in imaging sciences. Of particular importance is the analysis of wavefront sets and the correct…

Image and Video Processing · Electrical Eng. & Systems 2019-07-11 Héctor Andrade-Loarca , Gitta Kutyniok , Ozan Öktem , Philipp Petersen

We first describe how the Kashiwara involution on crystals of affine type $A$ is encoded by the combinatorics of aperiodic multisegments. This yields a simple relation between this involution and the Zelevinsky involution on the set of…

Representation Theory · Mathematics 2009-04-22 Nicolas Jacon , Cédric Lecouvey

The present paper develops a general methodology for the morphological segmentation of hyperspectral images, i.e., with an important number of channels. This approach, based on watershed, is composed of a spectral classification to obtain…

Image and Video Processing · Electrical Eng. & Systems 2020-10-05 Guillaume Noyel , Jesus Angulo , Dominique Jeulin

The time-dependent fields obtained by solving partial differential equations in two and more dimensions quickly overwhelm the analytical capabilities of the human brain. A meaningful insight into the temporal behaviour can be obtained by…

Numerical Analysis · Mathematics 2024-04-04 Miha Rot , Martin Horvat , Gregor Kosec

The performance of tip-enhanced optical microscopy is often limited by inefficient coupling of the excitation field to the plasmonic tip apex, as well as by thermal drift and optical aberrations. Here, we demonstrate that adaptive wavefront…

A point spread function of hexagonally segmented telescopes is derived by a new symmetrical formulation. By introducing three variables on a pupil plane, the Fourier transform of pupil functions is derived by a three-dimensional Fourier…

Instrumentation and Methods for Astrophysics · Physics 2018-11-28 Satoshi Itoh , Taro Matsuo , Shibai Hiroshi , Takahiro Sumi

High-quality flat optical elements require efficient light deflection to large angles and over a wide wavelength spectrum. Although phase gradient metasurfaces achieve this by continuously adding phase shifts in the range of 0 to 2{\pi} to…

Optics · Physics 2018-10-26 Claudio U. Hail , Dimos Poulikakos , Hadi Eghlidi
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