• Korean Journal of Optics and Photonics
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• v.15 no.5
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• pp.405-408
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• 2004

In this paper, we used a split-lens speckle shear interferometer using a double speckle interferometer, which enables continuous measurement of the deformation. We made two identical specklegrams corresponding to an object. With this method we could detect the measuring limits of the deformation for various shears. This experimental results showed that the measuring limits of a split-lens speckle shear interferometer are similar to the measuring limits of a double exposure speckle interferometer.

• Korean Journal of Optics and Photonics
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• v.3 no.2
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• pp.101-104
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• 1992

One of coefficients showing the degree of thermal effects is the thermooptic coefficient. It is the ratio of the refractive index change versus the change of temperture and was already measured by other general interferometric method. In this research, an optical system with the electronic speckle pattern interferometer complementing faults of the general interferometer was developed and its potentiality was validated experimentally.

• Journal of the Korean Society for Precision Engineering
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• v.24 no.11
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• pp.37-43
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• 2007

• Journal of the Korean Chemical Society
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• v.40 no.7
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• pp.531-534
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• 1996

• Proceedings of the Optical Society of Korea Conference
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• 2008.07a
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• pp.195-196
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• 2008

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.319-324
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• 1996

In this paper, radial sheared eletronic shearopgraphy was studied in order to measure vibration characteristics of circular or radial symmetric objects. We calculated amplitude of vibration by using eletro-optic holography theory, and utilized a porror prism for optical arrangement of sheared two images in this experiment. In this case, the data measured by shearing interferometer give us a distribution of the gradient of vibration amplitude. This developed system is applied to symmetical objects such as fans of airconditioner and circular plates to test vibration characteristics.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.21 no.12
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• pp.2047-2054
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• 1997

This paper describes a measuring method of vibration mode shapes by the Electronic Shearography. This method called the speckle interferometer has many merits in practical use, such as low sensitivity to environmental noise, low limit of coherent-length and simple optical configuration. In this study, we developed Michelson-type shearing interferometer provided with a phase stepping mirror and with a bias modulation mirror to quantify the vibration gradient fields. Results of application to a simple cantilever plate show that the vibration amplitude fields obtained are in good agreement with those of the electronic speckle pattern interferometry (ESPI).

• Journal of the Korean Institute of Telematics and Electronics
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• v.26 no.8
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• pp.1282-1289
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• 1989

Dual field speckle interferometry that is sensitive to the surface displacement of the object is constructed, and fringe patterns that have the displacement-informations are analysed using digital image processing. From 10\ulcorner to 80\ulcorner with respect to each specklegrams are obtained by double-exposure techniques, which are analysed by the proposed system and algorithm. Up to 10\ulcorner displacement, near measurable lower bound of Speckle Interferometry, fringe visibility is decreased due to decreasing fringe density, therefore relative errors are produced over 10% but over that displacement, relative errors are produced below 5%. Particularly, it is observed that spatial frequencies of each displacement are comparatively linear.