Radial shearing speckle pattern interference system based on a spatial light modulator

We propose a new radial shearing speckle pattern interference system. The introduction of radial shearing and the four-step temporal phase shift are realized using a spatial light modulator to modulate the phase information of the light wavefront. The modulation mode of the spatial light modulator is controlled by programming, and thus the shearing information can be adjusted quickly and arbitrarily according to the actual measurement needs. The interference system no longer has the requirement of the defect direction in nondestructive testing and can simultaneously realize the accurate detection of defects in all directions. The basic principle of radial shearing speckle pattern interferometry and the introduction method of radial shearing are described, and the system feasibility and practicability are verified by experiments.