Journal ArticleDOI
Very efficient speckle contrast reduction realized by moving diffuser device
Shigeo Kubota,Joseph W. Goodman +1 more
TLDR
Very efficient speckle contrast reduction is measured by temporal averaging using a moving diffuser on a tuning fork, which vibrates at 100 Hz over 60 microm in amplitude, a distance that is three times the surface roughness correlation length of the diffuser.Abstract:
Speckle noise reduction is best tested on a precise speckle contrast measurement bench, which should be able to measure 100% contrast in fully developed speckle as well as the smallest contrast (for example, less than 10%) after its reduction. On such a test bench, we have measured very efficient speckle contrast reduction by temporal averaging using a moving diffuser on a tuning fork, which vibrates at 100Hz over 60μm in amplitude, a distance that is three times the surface roughness correlation length of the diffuser.read more
Citations
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Journal ArticleDOI
Suppression of speckle patterns based on temporal angular decorrelation induced by multiple beamlets with diverse optical paths
Sunduck Kim,Young-Geun Han +1 more
TL;DR: In this article, the authors investigate an effective technique to alleviate the speckle contrast based on the temporal angular decorrelation induced by multiple beamlets with diverse optical paths by using a microlens array incorporating a galvo-mirror at the foci of two spherical lenses.
Proceedings ArticleDOI
Quasi noise-free reconstruction of long-wavelength digital holograms
TL;DR: The joint action of numerical ML (thought as a preprocessing filter) and 3D Block Matching in post-processing permits to overcome the theoretical limit of ML and to outperform the BM3D for the denoising of holograms.
Journal ArticleDOI
Speckle free efficient light engine for high power laser projectors and automobile headlamps
TL;DR: In this paper , a laser speckle reduction system is proposed for high-power laser-based projection imaging and illumination, which comprises a metallic ball-mirror connected with the mechanically dynamic and thermally conductive heat sink.
Journal ArticleDOI
Investigations of a wedge-shaped nematic liquid crystal cell using Mach–Zehnder interferometer
TL;DR: In this article, a wedge-shaped nematic liquid crystal cell was placed in one of the arms of the Mach-Zehnder interferometer to observe interference fringes.
Proceedings ArticleDOI
A method for total noise removal in digital holography based on enhanced grouping and sparsity enhancement filtering
TL;DR: In this article, the authors proposed a method specifically suitable to filter digital holography images that combines the two aforementioned strategies to overcome their respective limitations and demonstrate the effectiveness of this framework in three different experimental situations, i.e. reconstructions of single wavelength holograms and color holograms in the visible region and the challenging case of the Infrared Radiation Digital Holography (IRDH)
References
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Journal ArticleDOI
Introduction to Fourier Optics
Joseph W. Goodman,Mary E. Cox +1 more
TL;DR: The second edition of this respected text considerably expands the original and reflects the tremendous advances made in the discipline since 1968 as discussed by the authors, with a special emphasis on applications to diffraction, imaging, optical data processing, and holography.
Book
Introduction to Fourier optics
TL;DR: The second edition of this respected text considerably expands the original and reflects the tremendous advances made in the discipline since 1968 as discussed by the authors, with a special emphasis on applications to diffraction, imaging, optical data processing, and holography.
Journal ArticleDOI
Relation between the angular dependence of scattering and the statistical properties of optical surfaces
J. M. Elson,J. M. Bennett +1 more
TL;DR: In this paper, a relation from vector scattering theory has been used to predict the angular distribution of scattered light from optical surfaces as a function of the wavelength, optical constants of the material, and spectral density function.