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Related papers: Holographic laser Doppler ophthalmoscopy

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We present an original heterodyne holography method for digital holography that relies on two-dimensional heterodyne detection to record the phase and the amplitude of a f ield. The technique has been tested on objects as much as 13 mm in…

Optics · Physics 2011-12-22 Frédérique Le Clerc , Laurent Collot , Michel Gross

The comparison of optical reference frequency signals over free-space optical links is limited by the relative motion between local and remote sites. For ground to low earth orbit comparison, the expected Doppler shift and Doppler rate…

Aims: In this work, we discuss a way to combine High Dispersion Spectroscopy and High Contrast Imaging (HDS+HCI). For a planet located at a resolvable angular distance from its host star, the starlight can be reduced up to several orders of…

Optical imaging through scattering media is an important challenge in a variety of fields ranging from microscopy to autonomous vehicles. While advanced wavefront shaping techniques have offered significant breakthroughs in the past decade,…

Optics · Physics 2023-05-23 Omri Haim , Jeremy Boger-Lombard , Ori Katz

Cells alter the path of light, a fact that leads to well-known aberrations in single cell or tissue imaging. Optical diffraction tomography (ODT) measures the biophysical property that causes these aberrations, the refractive index (RI).…

Quantitative Methods · Quantitative Biology 2017-08-14 Mirjam Schürmann , Gheorghe Cojoc , Salvatore Girardo , Elke Ulbricht , Jochen Guck , Paul Müller

In digital holography, the coherent scattered light fields can be reconstructed volumetrically. By refocusing the fields to the sample planes, absorption and phase-shift profiles of sparsely distributed samples can be simultaneously…

Optics · Physics 2023-02-10 Jian Zhao , Yuzhuo Wang , Xing Huang , Saijun Wu

Fourier imaging is an indirect imaging method which records the diffraction pattern of the object scene coherently in the focal plane of the imaging system and reconstructs the image using computational resources. The spatial resolution,…

Optics · Physics 2023-06-05 Hui Yuan , Alvydas Lisauskas , Mark D. Thomson , Hartmut G. Roskos

A laser Doppler imaging scheme combined to an upright microscope is proposed. Quantitative Doppler imaging in both velocity norm and direction, as well as amplitude contrast of either zebrafish flesh or vasculature is demonstrated.

Optics · Physics 2015-01-08 Nicolas Verrier , Daniel Alexandre , Pascal Picart , Michel Gross

We introduce the first method to enable an optical amplification of a coherent Raman spectroscopy signal called radio frequency Doppler Raman spectroscopy. Doppler Raman measurements amplify the optical signals in coherent Raman…

We report on the first spectroscopic observation of the rotational Doppler shift associated with light beams carrying orbital angular momentum. The effect is evidenced as the broadening of a Hanle/EIT coherence resonance on Rb vapor when…

Quantum Physics · Physics 2009-11-13 S. Barreiro , J. W. R. Tabosa , H. Failache , A. Lezama

In both light optics and electron optics, the amplitude of a wave scattered by an object is an observable that is usually recorded in the form of an intensity distribution in a real space image or a diffraction image. In contrast, retrieval…

For measurements designed to accurately determine layer thickness, there is a natural trade-off between sensitivity to optical thickness and lateral resolution due to the angular ray distribution required for a focused beam. We demonstrate…

A lateral shear interferometer based digital holographic microscopy has been realized to study the morphology dynamics of Human red blood cells quantitatively. Here, a lateral shear interferometer is embedded with a conventional microscope…

Image and Video Processing · Electrical Eng. & Systems 2019-09-10 Shital Devinder , Ashish Lal , Tathagato Rai Dastidar , Satish Kumar Dubey

The almost unexplored frequency window from submillimeter to mid-infrared (mid-IR) may bring new clues about the particle acceleration and transport processes and the atmospheric thermal response during solar flares. Because of its…

We are developing a stable and precise spectrograph for the Large Binocular Telescope (LBT) named "iLocater." The instrument comprises three principal components: a cross-dispersed echelle spectrograph that operates in the YJ-bands…

We study Doppler velocity measurements at multiple heights in the solar atmosphere using a set of six filtergrams obtained by the Helioseismic magnetic Imager on board the Solar Dynamics Observatory. There are clear and significant phase…

Solar and Stellar Astrophysics · Physics 2014-01-15 Kaori Nagashima , Laurent Gizon , Aaron Birch , Björn Löptien , Sebastien Couvidat , Bernhard Fleck

It is well known that by modifying the wavefront in a certain manner, the light intensity can be turned into a certain shape. However, all known light modulation techniques allow for limited light modifications only: focusing within a…

Optics · Physics 2016-05-23 Tatiana Latychevskaia , Hans-Werner Fink

We demonstrate wide-angle, broadband and efficient reflection holography by utilizing coupled dipole-patch nano-antenna cells to impose an arbitrary phase profile on of the reflected light. High fidelity images were projected at angles of…

Optics · Physics 2017-02-15 Yuval Yifat , Michal Eitan , Zeev Iluz , Yael Hanein , Amir Boag , Jacob Scheuer

Holography has always held special appeal, for it is able to record and display spatial information in three dimensions. Here, we show how to augment the capabilities of digital holography by using a large number of narrow laser lines at…

Second harmonic generation (SHG) microscopy is a valuable tool for optical microscopy. SHG microscopy is normally performed as a point scanning imaging method, which lacks phase information and is limited in spatial resolution by the…