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A novel fabrication method for soft x-ray transmission grating and other optical elements is presented. The method uses Focused-Ion-Beam (FIB) technology to fabricate high-quality free standing grating bars on Transmission Electron…

Optics · Physics 2015-06-05 G. Hurvitz , Y. Ehrlich , G. Strum , Z. Shpilman , I. Levy , M. Fraenkel

We discuss the applicability of holographically recorded gratings in photopolymers and holographic polymer-dispersed liquid crystals as neutron optical elements. An experimental investigation of their properties for light and neutrons with…

Metacalibration is a recently introduced method to accurately measure weak gravitational lensing shear using only the available imaging data, without need for prior information about galaxy properties or calibration from simulations. The…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-31 Erin S. Sheldon , Eric M. Huff

This paper addresses the problem of mirror surface reconstruction, and proposes a solution based on observing the reflections of a moving reference plane on the mirror surface. Unlike previous approaches which require tedious calibration,…

Computer Vision and Pattern Recognition · Computer Science 2021-01-26 Kai Han , Miaomiao Liu , Dirk Schnieders , Kwan-Yee K. Wong

We derive from first principles the expression for the angular/wavelength distribution of the intensity diffracted by a blazed reflective grating, according to a scalar theory of diffraction. We considered the most common case of a groove…

Optics · Physics 2015-06-22 R. Casini , P. G. Nelson

Hyperspectral image (HSI) densely samples the world in both the space and frequency domain and therefore is more distinctive than RGB images. Usually, HSI needs to be calibrated to minimize the impact of various illumination conditions. The…

Computer Vision and Pattern Recognition · Computer Science 2024-12-23 Zhuoran Du , Shaodi You , Cheng Cheng , Shikui Wei

Estimating camera poses is a fundamental task for 3D reconstruction and remains challenging given sparsely sampled views (<10). In contrast to existing approaches that pursue top-down prediction of global parametrizations of camera…

Computer Vision and Pattern Recognition · Computer Science 2024-04-05 Jason Y. Zhang , Amy Lin , Moneish Kumar , Tzu-Hsuan Yang , Deva Ramanan , Shubham Tulsiani

Cross-grating phase microscopy (CGM) is a quantitative phase microscopy technique based on the association of a 2-dimensional diffraction grating (cross-grating) and a regular camera sensor, separated by a millimetric distance. This simple…

Optics · Physics 2024-11-04 Baptiste Marthy , Guillaume Baffou

Future observatories utilizing reflection grating spectrometers for extreme ultraviolet (EUV) and soft X-ray (SXR) spectroscopy require high-fidelity gratings with both blazed groove facets and custom groove layouts that are often fanned or…

Instrumentation and Methods for Astrophysics · Physics 2020-03-17 Jake A. McCoy , Randall L. McEntaffer , Drew M. Miles

Nonlinear lens distortion rectification is a common first step in image processing applications where the assumption of a linear camera model is essential. For rectifying the lens distortion, forward distortion model needs to be known.…

Computer Vision and Pattern Recognition · Computer Science 2017-07-05 Burak Benligiray , Cihan Topal

Diffraction gratings disperse light in a rainbow of colors with the opposite order than refractive prisms, a phenomenon known as negative dispersion. While refractive dispersion can be controlled via material refractive index, diffractive…

Optics · Physics 2017-06-21 Ehsan Arbabi , Amir Arbabi , Seyedeh Mahsa Kamali , Yu Horie , Andrei Faraon

A new approach was proposed to accurately determine the thickness of film, especially for ultra-thin film, through spectrum fitting with the assistance of interference layer. The determination limit can reach even less than 1 nm. Its…

Optics · Physics 2016-06-20 Xingxing Liu , Shao-Wei Wang , Hui Xia , Xutao Zhang , Ruonan Ji , Tianxin Li , Wei Lu

The Zero Contrast Grating (ZCG) is a promising candidate for moded and dispersive mid-infrared (MIR) photonics for its broadband transmittance and reflectance greater than 99.9%. The optimal grating design including refractive index and…

Optics · Physics 2023-12-06 Ken Araki , Richard Z. Zhang

Measuring the diffuse, highly-ionized baryonic content in galactic halos and the intergalactic medium through soft x-ray absorption spectroscopy of active galactic nuclei is a main scientific objective of the Lynx X-ray Observatory mission…

Instrumentation and Methods for Astrophysics · Physics 2022-06-17 Jake A. McCoy

Astrophysics demands higher precision in measurements across photometry, spectroscopy, and astrometry. Several science cases necessitate not only precision but also a high level of accuracy. We highlight the challenges involved,…

Instrumentation and Methods for Astrophysics · Physics 2025-01-20 Luca Pasquini , Dinko Milaković

Silicon immersion gratings and grisms enable compact, near-infrared spectrographs with high throughput. These instruments find use in ground-based efforts to characterize stellar and exoplanet atmospheres, and in space-based observatories.…

Instrumentation and Methods for Astrophysics · Physics 2020-12-15 Emily Lubar , Daniel T. Jaffe , Cynthia Brooks , Sierra Hickman , Michael Gully-Santiago , Gregory Mace

In this paper, we present a novel zero-shot camera calibration method that estimates camera parameters with no calibration image. It is common sense that we need at least one or more pattern images for camera calibration. However, the…

Computer Vision and Pattern Recognition · Computer Science 2020-12-01 Jae-Yeong Lee

The diffraction spectrum of coherent waves scattered from fractal supports is calculated exactly. The fractals considered are of the class generated iteratively by successive dilations and translations, and include generalizations of the…

Condensed Matter · Physics 2009-10-28 Daniel A. Hamburger-Lidar

Measurement and analysis of diffraction parameters of thick transmission holographic phase gratings recorded on PHC-488 photopolymer are presented. Precision determination of the spatial grating period is executed by Bragg angle measurement…

Optics · Physics 2015-12-07 E. A. Tikhonov , A. K. Lyamets

Most approaches to camera calibration rely on calibration targets of well-known geometry. During data acquisition, calibration target and camera system are typically moved w.r.t. each other, to allow image coverage and perspective…

Computer Vision and Pattern Recognition · Computer Science 2021-10-15 Annika Hagemann , Moritz Knorr , Christoph Stiller
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