N
N. Takai
Researcher at Hokkaido University
Publications - 38
Citations - 671
N. Takai is an academic researcher from Hokkaido University. The author has contributed to research in topics: Speckle pattern & Diffraction. The author has an hindex of 17, co-authored 38 publications receiving 659 citations.
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Real-time velocity measurement for a diffuse object using zero-crossings of laser speckle
TL;DR: In this paper, a new method for measuring the in-plane velocity of a moving diffuse object by using the technique of zero-crossings for the intensity fluctuation of spatially integrated laser speckles is proposed.
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Statistical properties of laser speckles produced under illumination from a multimode optical fiber
N. Takai,Toshimitsu Asakura +1 more
TL;DR: In this article, the authors studied the statistical properties of both speckle patterns incident upon and emerging from a diffuse object under illumination of the laser light generated from a multimode optical fiber.
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New common-path phase shifting interferometer using a polarization technique.
TL;DR: The present interferometer is different from a shearing type in that the phase distribution of an object beam is directly analyzed from the acquired intensity variations obtained by a 2-D detector such as a TV camera.
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Correlation distance of dynamic speckles.
TL;DR: The translational and boiling motions of dynamic speckles produced in the Fresnel diffraction field under illumination of a Gaussian beam are investigated in detail and the characteristics for the correlation distance of time-varying speckle intensity fluctuations are verified by several experiments.
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Dynamic statistical properties of laser speckle due to longitudinal motion of a diffuse object under Gaussian beam illumination
TL;DR: In this article, the authors investigated the statistical properties of laser speckle produced in the far-field diffraction region from a diffuse object moving longitudinally along the optical axis under illumination of a Gaussian beam.