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Simple Versatile Shearing Interferometer Suitable For Measurements On A Microscopic Scale, Emilia Mihaylova, Vincent Toal
Simple Versatile Shearing Interferometer Suitable For Measurements On A Microscopic Scale, Emilia Mihaylova, Vincent Toal
Articles
Microelectromechanical systems (MEMS) behave differently from massive samples. Conventional testing and inspection techniques usually fail at the microscale. Recently there has been an increasing interest in the application of optical techniques for microstructure testing, because they are high-resolution, non-contact, full-field, fast and relatively inexpensive. New interferometric systems, which are suitable for microscopic optical metrology, are of interest for engineering and industrial applications. A modified electronic speckle pattern shearing interferometer (ESPSI) with a very simple shearing device has been designed for metrology applications on the microscale. The shearing device consists of two partially reflective glass plates. The reflection coefficients of the …
Comparison Of Three Electronic Speckle Pattern Shearing Interferometers Using Photopolymer Holographic Optical Elements., Emilia Mihaylova, Izabela Naydenova, Vincent Toal, Suzanne Martin
Comparison Of Three Electronic Speckle Pattern Shearing Interferometers Using Photopolymer Holographic Optical Elements., Emilia Mihaylova, Izabela Naydenova, Vincent Toal, Suzanne Martin
Conference Papers
Three electronic speckle pattern shearing interferometers (ESPSI) using photopolymer holographic gratings to produce the sheared image are presented. In the first ESPSI system two holographic gratings are used. The gratings are placed between the object and an imaging lens in front of the CCD camera. In the second ESPSI system one grating is used in combination with a sheet of ground glass. The sheared images on the ground glass are further imaged onto a CCD camera. In the third ESPSI system only one grating is used - it is placed in front of the object. The image and the sheared …
Electronic Speckle Pattern Shearing Interferometry Using Photopolymer Diffractive Optical Elements For Vibration Measurements, Emilia Mihaylova, Izabela Naydenova, Suzanne Martin, Vincent Toal
Electronic Speckle Pattern Shearing Interferometry Using Photopolymer Diffractive Optical Elements For Vibration Measurements, Emilia Mihaylova, Izabela Naydenova, Suzanne Martin, Vincent Toal
Conference Papers
Electronic speckle pattern shearing interferometry (ESPSI) is superior to Electronic speckle pattern interferometry (ESPI) when strain distribution, arising from object deformation or vibration, need to be measured. This is because shearography provides data directly related to the spatial derivatives of the displacement. Further development of ESPSI systems could be beneficial for wider application to the measurement of mechanical characteristics of vibrating objects. Two electronic speckle pattern shearing interferometers (ESPSI) suitable for vibration measurements are presented. In both ESPSI systems photopolymer holographic gratings are used to shear the images and to control the size of the shear. The holographic gratings are …