The Experts below are selected from a list of 177 Experts worldwide ranked by ideXlab platform
Yukihiro Ishii - One of the best experts on this subject based on the ideXlab platform.
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Correction of quadratic phase error in two-wavelength digital Holographic Interferometry using laser diodes
Optics Communications, 2012Co-Authors: Hideki Funamizu, Tsuyoshi Kato, Yoshihisa Aizu, Yukihiro IshiiAbstract:Abstract We present the correction of a quadratic phase error in two-wavelength digital Holographic Interferometry using laser diodes. This phase error arises from numerical reconstructions of wavefronts from digital holograms based on the Fresnel diffraction integral. To correct the quadratic phase error, it is numerically produced by computer on the basis of the theoretical prediction and is subtracted from the phase difference map in two-wavelength digital Holographic Interferometry. Experimental results show that the method of correction in this paper is useful for two-wavelength digital Holographic Interferometry using laser diodes.
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multiple wavelength digital Holographic Interferometry using tunable laser diodes
Applied Optics, 2008Co-Authors: Atsushi Wada, Makoto Kato, Yukihiro IshiiAbstract:Here we present multiple-wavelength digital Holographic Interferometry with a wide measurement range using laser diodes. Small wavelength differences can be easily realized by the wavelength tuning of laser diodes with injection current controls. A contour map of an object with a wide measurement range and a high sensitivity is demonstrated by combining a few contour maps with several measurement sensitivities. Synthetic wavelengths are calibrated using a known height difference. This alleviates the need to have high precise knowledge of the recording wavelengths. The synthetic wavelengths ranged from ~3 mm for high measurement sensitivity to ~4 cm for wide measurement range. An rms error of ~35 μm for a ~1 cm height measurement is shown. The measured profile of Holographic Interferometry agrees with a standard stylus instrument.
Patrice Tankam - One of the best experts on this subject based on the ideXlab platform.
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Wake flows analysis by digital color Holographic Interferometry
Biomedical Optics and 3-D Imaging, 2010Co-Authors: Jean-michel Desse, Pascal Picart, Patrice TankamAbstract:Digital 3? Holographic Interferometry is shown for analyzing the variations in the refractive index induced by the wakeflow around a circular cylinder.
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Candle flame analysis by digital three-wavelength Holographic Interferometry
Fringe 2009, 2009Co-Authors: Jean-michel Desse, Pascal Picart, Patrice TankamAbstract:More and more, computational fluid dynamics needs to be validated by fine measurements in a smaller space or shorter time, or both at once. This is why ONERA has developed optical methods based on real-time true color Holographic Interferometry using transmission or reflection Holographic plates [1]. This last technique combines the advantages of differential Interferometry with those of monochromatic Holographic Interferometry. With this, not only small path differences but also large ones can be measured because the interference fringe diagram obtained is colored, very broad and well-contrasted. Also, color Holographic Interferometry generates the achromatic fringe and also provides absolute data throughout the entire field of observation. But, these methods are depending on Holographic plates. In fact, plates are used as reference hologram and chemical treatment is a disadvantage because it produces variations in the gelatin thickness. A possibility to avoid chemical processing is related to digital three-color Holographic Interferometry.
Liyun Zhong - One of the best experts on this subject based on the ideXlab platform.
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Caustic phenomena in Holographic Interferometry
Practical Holography XVII and Holographic Materials IX, 2003Co-Authors: Bingheng Xiong, Liyun Zhong, Zhengrong Wang, Runhai Yang, Jin-ming Zhao, Shunyun ChenAbstract:In a series of the experiments of real-time Holographic Interferometry, some dark shadow areas appear among the interference fringes. The appearing of the dark shadow area plays a very important role in the fracture process. We find that the appearing of these dark shadow regions are the phenomena of caustic in Fracture Mechanics. The shadow region is so called shadow spot in Fracture Mechanics and the factor of stress intensity can be calculated by measuring the size of the correosponding length of the shadow spot and the strain field can be calculated by traditional Holographic method. Therefore, Holographic method and caustic method can be combined together in Holographic Interferometry and it will lead to a wide application in Experimental Mechanics.
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Some novel methods in real-time Holographic Interferometry
Practical Holography XVI and Holographic Materials VIII, 2002Co-Authors: Bingheng Xiong, Zhengrong Wang, Liyun ZhongAbstract:Six novel methods in real-time Holographic Interferometry recently worked out by the authors of this paper. They are: the one for recording a real-time hologram with high contrast interference fringes and high brightness of the testing optics field, the one for measuring the phase modulation of a thin-phase hologram, the one for controlling the phase modulation in making a real-time hologram, the one for measuring in the 'reference wave field', the one for fast predicting the direction of displacement, and the one for avoiding the light reflected from the surfaces of collimation lens. All these methods are helpful to holographers in pursuit of high precision and efficiency in real-time Holographic Interferometry.
Tatiana Kukhtareva - One of the best experts on this subject based on the ideXlab platform.
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Single beam dynamic Holographic Interferometry
Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications IV, 2010Co-Authors: Nickolai V Kukhtarev, Tatiana KukhtarevaAbstract:Single beam dynamic Holographic recording is realized in the photorefractive crystals. Different photorefractive mechanisms of Holographic recording are discussed. Feasibility of single beam Holographic Interferometry with the transparent and opaque objects (like oil and water droplets) in transmission and reflection is demonstrated.
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Single beam dynamic Holographic Interferometry
Biomedical Optics and 3-D Imaging, 2010Co-Authors: Nickolai V Kukhtarev, Tatiana KukhtarevaAbstract:Single beam dynamic Holographic recording is realized in the photorefractive crystals. Different photorefractive mechanisms of Holographic recording are discussed. Feasibility of single beam Holographic Interferometry with opaque (reflective) and transparent objects is demonstrated.
Nickolai V Kukhtarev - One of the best experts on this subject based on the ideXlab platform.
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Single beam dynamic Holographic Interferometry
Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications IV, 2010Co-Authors: Nickolai V Kukhtarev, Tatiana KukhtarevaAbstract:Single beam dynamic Holographic recording is realized in the photorefractive crystals. Different photorefractive mechanisms of Holographic recording are discussed. Feasibility of single beam Holographic Interferometry with the transparent and opaque objects (like oil and water droplets) in transmission and reflection is demonstrated.
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Single beam dynamic Holographic Interferometry
Biomedical Optics and 3-D Imaging, 2010Co-Authors: Nickolai V Kukhtarev, Tatiana KukhtarevaAbstract:Single beam dynamic Holographic recording is realized in the photorefractive crystals. Different photorefractive mechanisms of Holographic recording are discussed. Feasibility of single beam Holographic Interferometry with opaque (reflective) and transparent objects is demonstrated.
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determination of model airplane attitudes using dynamic Holographic Interferometry
Applied Optics, 2008Co-Authors: Partha P Banerjee, Georges Nehmetallah, Nickolai V Kukhtarev, Sarat C PraharajAbstract:We demonstrate how real-time Holographic Interferometry yielding two-dimensional fringes can be recorded and used to determine changes in three-dimensional attitude of a model airplane through digital image processing. A simple bench-top experiment with a model airplane as a test object is conducted to demonstrate interference fringes superposed on the image due to changes in attitudes (pitch, yaw, and roll) as well as distortion. A novel second-generation thermoplastic camera suitable for dynamic multiple reversible registration of thin-phase holograms using thermoplastic and semiconductor film on glass substrate is used for in situ recording and readout during real-time Holographic Interferometry. Thin-phase holograms also offer the advantage of exact image reconstruction from forward-phase conjugation.