Digital speckle pattern shearing interferometry, also called digital shearography, is an optical interferometric technique which have already been applied by industry for the purposes of the nondestructive testing (NDT), strain and stress measurement and vibration analysis. In general, the used laser with a relatively large coherent length has applied in the measuring device. It is obviously that this kind of laser is expensive in price and large in volume. Thus the development of a simple, mobile and inexpensive industrial testing tool is limited. This paper will focus on the application of the simple laser diode without temperature stabilization and without additional expanding lens in the digital shearographic interferometry. The measuring devices using this kind of laser diode is presented. Its applications in the areas of NDT, strain measurement and vibration analysis are demonstrated. The development of a small and mobile measuring device in conjunction with a user guided comfortable program Shearwin enable the digital speckle pattern shearing interferometry to be developed easily into an industrial on line testing tool.
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