• Laser & Optoelectronics Progress
  • Vol. 51, Issue 11, 111201 (2014)
Cai Changqing*, Zhang Yongshan, Wang Dayang, Han Qihao, and Tang Chengzhi
Author Affiliations
  • [in Chinese]
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    DOI: 10.3788/lop51.111201 Cite this Article Set citation alerts
    Cai Changqing, Zhang Yongshan, Wang Dayang, Han Qihao, Tang Chengzhi. Research on New Shearing Speckle Interferometry System[J]. Laser & Optoelectronics Progress, 2014, 51(11): 111201 Copy Citation Text show less

    Abstract

    Shearing speckle interferometry is a well known optical tool for qualitative as well as quantitative measurements of displacement components′ derivatives of engineering structures subjected either static or dynamic load. Shearing speckle interferometry, based on Mach-Zehnder interferometer, suffers from the disadvantage of low light efficiency due to the structure. A novel digital shearography set-up with two fold which can improve light efficiency for the measurement of first order derivative of out-of-plane displacement (slope) is demonstrated. There is a double aperture mask in front of the imaging lens for spatial phase shifting. Independent control of the shear and the frequency of the spatial carrier can be attained with this set-up. A shear is introduced between the two scattered fields. The double aperture which can introduce spatial carrier fringes within the speckle for spatial phase shifting is employed in this system. Phase extraction is obtained through advanced sinusoidal-fitting method, which is applied to interference patterns with a spatial carrier in the primary fringes. The experimental implementation of the set-up and the results obtained with it are presented and discussed.
    Cai Changqing, Zhang Yongshan, Wang Dayang, Han Qihao, Tang Chengzhi. Research on New Shearing Speckle Interferometry System[J]. Laser & Optoelectronics Progress, 2014, 51(11): 111201
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