Robust dynamic phase-shifting common-path shearography using LCPG and pixelated micropolarizer array

A concise and dependable dynamic phase-shifting shearography system based on common-path interferometer is proposed. Two lateral sheared images with common optical path are generated using a liquid crystal polarization grating (LCPG). The sheared images of the object under test interfere with each other, and a pixelated micropolarizer array is used to introduce pixelated carrier, enabling the measurement of dynamic deformation using dynamic phase-shifting. Compared with the ordinary imaging system, the shearography system only needs to insert LCPG between an imaging lens and a camera with pixelated micropolarizer array. The system is resilient to environmental disturbances benefitting from the compact common-path and dynamic phase-shifting method. Theoretical analysis and experiments have been completed, showing that the system can fully exploit the advantages of shearography and improve the reliability of shearography applications.

Automated summary

The proposed dynamic phase-shifting shearography system utilizes a common-path interferometer and dynamic phase-shifting technique to achieve reliable and concise deformation measurement. The system's compact structure and resilience to environmental disturbances enhance the reliability of shearography applications.