Jiang Hanyang, Ma Yinhang, Dai Meiling, Dai Xiangjun, Yang Fujun, He Xiaoyuan
Appl Opt. 2020 Jul 1;59(19):5812-5820. doi: 10.1364/AO.394218.
A panoramic dual-directional shearography system is proposed to simultaneously determine out-of-plane deformation derivatives in two directions and globally inspect the object to be tested. A dichroic filter (DF), a 3CCD camera, and dual-wavelength light are used in the proposed shearography configuration. The dual-wavelength light coupled with the corresponding imaging sensors of the 3CCD camera provides independent color signals and shearograms. Through adjustment of the tilted stereo-angle of the DF, which offers a second wavelength-dependent measurement, an additional independent image-shearing can be introduced into the setup. The auxiliary bi-mirror surrounding the object helps to fully illuminate the object surface and capture it in a single shot. Theoretical analysis and experimental results demonstrated the utility of the system.
