Design and experiment of electronic speckle shearing phase-shifting   pattern interferometer
  An electronic speckle shearing phase-shifting pattern interferometer (ESSPPI) based on Michelson interferometer was based in this paper. A rotatable mirror driven by a step motor in one of its reflective arm is used to generate an adjustable shearing and the mirror driven by piezoelectric transducer (PZT) in the other reflective arm was used to realize phaseshifting. In the experiments, the deformation of an aluminum plate with the same extern-force on different positions and different forces on the same position is measured. Meanwhile, the phase distribution and phase-unwrap image of the aluminum plate with the extern-force on its center position is obtained by the four-step phase-shifting method. 
Tianhua Xu, Chao Jing, Wencai Jing, Hongxia Zhang, Dagong Jia, Yimo   Zhang
physics.ins-det physics.optics