A robust phase extraction method for overcoming spectrum overlapping in shearography

In the same way as the traditional optical interference technique, shearography obtains object deformation information by obtaining the phase, and the measured object is often dynamic in practical applications, so the spatial carrier method, which can extract the phase information from a single speckle pattern, becomes a necessary phase extraction method for the practicalization of shearography. However, due to the coupling relationship between shearing amount and spatial carrier frequency, the spatial carrier method often suffers from spectrum overlapping, which seriously affects the quality of the extracted phase.