Journal ArticleDOI
Time-average readout of speckle photographs by laser illumination from a vibrating optical fiber
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TLDR
In this paper, the time-averaging effect on fringes produced from a specklegram under time-varying speckle illumination, by which undesirable specckle noise is successfully reduced, is studied.Abstract:
The time-averaging effect on fringes produced from a specklegram under time-varying speckle illumination, by which undesirable speckle noise is successfully reduced, is studied. In this method, a specklegram is illuminated by laser speckles emerging from a vibrating multimode optical fiber. The characteristics of time-averaged fringes are revealed theoretically and experimentally by taking into consideration the deformation of speckles recorded on the specklegram and the correlation area of speckles from the multimode optical fiber.read more
Citations
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Journal ArticleDOI
Ultrashort pulse train generation through induced modulational polarization instability in a birefringent Kerr-like medium
Stefano Trillo,Stefan Wabnitz +1 more
TL;DR: In this article, the authors predict that, by inducing modulational polarization instabilities, one may generate a train of ultrashort pulses from continuous-wave (cw) radiation propagating in a birefringent optical fiber.
Journal ArticleDOI
Spatiotemporal supermodes: Rapid reduction of spatial coherence in highly multimode lasers
Ronen Chriki,Simon Mahler,Simon Mahler,Chene Tradonsky,Vishwa Pal,Asher A. Friesem,Nir Davidson +6 more
TL;DR: In this paper, the spatial coherence of highly multimode laser in the regime of short timescales was investigated and it was shown that in this regime, the temporal (longitudinal) modes play a crucial role in spatiotemporal reduction.
Patent
Reflection monitor optical fiber coupler manufacturing system and method
Eisuke Sasaoka,Masumi Fukuma,Hiroaki Takimoto,Hiroshi Suganuma,Hiroshi Yokota,Junichi Yoshikawa,Arimoto Kazuhiko +6 more
TL;DR: In this article, an exact splitting ratio for optical fiber coupler fabrication is obtained by exploiting the advantageous feature of the reflection monitor method, where the fiber connection work for each fiber coupling is not required.
Journal ArticleDOI
Laser speckles produced by a diffuse object under illumination from a multimode optical fiber: an experimental study
N. Takai,Toshimitsu Asakura +1 more
TL;DR: The size and displacement of speckles produced by a diffuse object under illumination from a multimode optical fiber are investigated experimentally to confirm the theory presented in a previous paper.
Journal ArticleDOI
Color digital holography using speckle illumination by means of a multi-mode fiber
TL;DR: In this article, a multi-mode fiber is used for color digital holography using speckle illumination by means of a multiuser vibrator, and a number of holograms are acquired to average reconstructed images.
References
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Journal ArticleDOI
Recording of In-plane Surface Displacement by Double-exposure Speckle Photography
TL;DR: In this article, the authors measured local displacements in the plane of an object surface illuminated by coherent light by recording double-exposure photographs of it and using the optical transform of the negative image.
Journal ArticleDOI
Displacement Measurement from Double-exposure Laser Photographs
E. Archbold,A.E. Ennos +1 more
TL;DR: In this paper, surface displacement can be measured by recording a double-exposure photograph of the laser-illuminated object, followed by optical processing of the recorded speckle-pattern image.
Dynamic Laser Speckles and their Application to Velocity Measurements of the Diffuse Object
TL;DR: In this paper, the statistical properties of dynamic speckles produced in the diffraction and image fields by the diffuse object moving in a plane with constant velocity are examined in detail, and two typical speckle motions of translation and boiling are interpreted for various optical configurations in the Diffraction and Image Fields.
Journal ArticleDOI
Dynamic laser speckles and their application to velocity measurements of the diffuse object
Toshimitsu Asakura,N. Takai +1 more
TL;DR: In this article, the statistical properties of dynamic speckles produced in the diffraction and image fields by the diffuse object moving in a plane with constant velocity are examined in detail, and two typical speckle motions of translation and boiling are interpreted for various optical configurations in the Diffraction and Image Fields.
Journal ArticleDOI
Application of Speckling for In-plane Vibration Analysis
TL;DR: In this paper, the Fourier transform of in-plane moving objects is used to measure the lateral displacement of the moving object and its time averaged and doubly exposed speckle patterns.