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We propose methods that use specular, multibounce lidar returns to detect and map specular surfaces that might be invisible to conventional lidar systems that rely on direct, single-scatter returns. We derive expressions that relate the…

Computer Vision and Pattern Recognition · Computer Science 2023-02-22 Connor Henley , Siddharth Somasundaram , Joseph Hollmann , Ramesh Raskar

Speckle metrology is a powerful tool in the measurement of wavelength and spectra. Recently, speckle produced by multiple reflections inside an integrating sphere has been proposed and showed high performance. However, to our knowledge, a…

Optics · Physics 2021-10-19 Morgan Facchin , Kishan Dholakia , Graham D. Bruce

Light rays incident on a transparent object of uniform refractive index undergo deflections, which uniquely characterize the surface geometry of the object. Associated with each point on the surface is a deflection map (or spectrum) which…

Computer Vision and Pattern Recognition · Computer Science 2015-07-15 Prasad Sudhakar , Laurent Jacques , Xavier Dubois , Philippe Antoine , Luc Joannes

We present 36 observations of 17 visual binaries of moderate separation (range from 0.15'' to 0.79'') made with the 50 cm Cassegrain telescope of the Jagiellonian University in Cracow. The speckle interferometry technique was combined with…

Astrophysics · Physics 2009-11-11 Artur Rutkowski , Waclaw Waniak

This manuscript will unify inverse freeform reflector design and surface light scattering to design freeform reflectors with a scattering surface. We use microfacets, which are small, tilted mirrors superimposed on a smooth surface. We form…

Remote sensing hyperspectral and more generally spectral instruments are common tools to decipher surface features in Earth and Planetary science. While linear mixture is the most common approximation for compounds detection (mineral,…

Earth and Planetary Astrophysics · Physics 2023-05-03 Frédéric Schmidt

Optical spectroscopy techniques such as differential reflectance and transmittance have proven to be very powerful techniques to study 2D materials. However, a thorough description of the experimental setups needed to carry out these…

Simultaneously sensing and resolving the position of measurands along an optical fiber enables numerous opportunities, especially for application in environments where massive sensor deployment is not feasible. Despite significant progress…

Optics · Physics 2023-01-25 Luis Costa , Zhongwen Zhan , Alireza Marandi

Transmission spectra of metallic films or membranes perforated by arrays of subwavelength slits or holes have been widely interpreted as resonance absorption by surface plasmon polaritons (SPPs). Alternative interpretations involving…

Optics · Physics 2009-11-11 G. Gay , O. Alloschery , B. Vairis de Lesegno , J. Weiner , H. J. Lezec

Optical interferometry has proven extremely powerful to investigate some of the most fundamental laws of physics, using light with very precisely controlled geometry. In the past few decades, various speckle metrology methods have emerged…

Optics · Physics 2022-11-07 Guillaume Graciani , Marcel Filoche , Francois Amblard

I propose a spatial-mode demultiplexing (SPADE) measurement scheme for the far-field imaging of spatially incoherent optical sources. For any object too small to be resolved by direct imaging under the diffraction limit, I show that SPADE…

Optics · Physics 2017-03-01 Mankei Tsang

Optical stellar interferometers have demonstrated milli-arcsecond resolution with few apertures spaced hundreds of meters apart. To obtain rich direct images, many apertures will be needed, for a better sampling of the incoming wavefront.…

Instrumentation and Methods for Astrophysics · Physics 2014-09-17 Arun Surya , Swapan K. Saha , Antoine Labeyrie

Spectroastrometry is a technique which has the potential to resolve flux distributions on scales of milliarcseconds. In this study, we examine the application of spectroastrometry to binary point sources which are spatially unresolved due…

Astrophysics · Physics 2009-11-10 John M. Porter , Rene D. Oudmaijer , Debbie Baines

Diffraction-based methods have become an invaluable tool for the detailed assessment of residual strain and stress within experimental mechanics. These methods typically measure a component of the average strain within a gauge volume. It is…

Applied Physics · Physics 2019-02-25 J. N. Hendriks , C. M. Wensrich , A. Wills , V Luzin , A. W. T Gregg

The useful dynamic range of an image in the diffraction limited regime is usually limited by speckles caused by residual phase errors in the optical system forming the image. The technique of speckle decorrelation involves introducing many…

Astrophysics · Physics 2007-05-23 Anand Sivaramakrishnan , James P. Lloyd , Philip E. Hodge , Bruce A. Macintosh

The displacement field in highly non uniformly strained crystals is obtained by addition of constraints to an iterative phase retrieval algorithm. These constraints include direct space density uniformity and also constraints to the sign…

Materials Science · Physics 2009-11-11 A. A. Minkevich , M. Gailhanou , J. -S. Micha , B. Charlet , V. Chamard , O. Thomas

Reflectometry is a technique that uses the light reflected by a sample to determine properties of the sample. Interferometric reflectometry uses interference between two beams, one of which is incident on ---and reflected back by--- a…

Optics · Physics 2019-10-10 Alexander Nahmad-Rohen , Wolfgang Langbein

The imaging sharpness of an X-ray telescope is chiefly determined by the optical quality of its focusing optics, which in turn mostly depends on the shape accuracy and the surface finishing of the grazing-incidence X-ray mirrors that…

Instrumentation and Methods for Astrophysics · Physics 2014-12-10 Lorenzo Raimondi , Daniele Spiga

Infrared (IR) spectroscopy is an indispensable tool for many practical applications including material analysis and sensing. Existing IR spectroscopy techniques face challenges related to the inferior performance and the high cost of…

Optics · Physics 2017-03-13 Anna Paterova , Shaun Lung , Dmitry Kalashnikov , Leonid Krivitsky

The detection of exoplanets in coronographic images is severely limited by residual starlight speckles. Dedicated post-processing can drastically reduce this "stellar leakage" and thereby increase the faintness of detectable exoplanets.…

Instrumentation and Methods for Astrophysics · Physics 2017-11-08 Nicholas Devaney , Éric Thiébaut
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