Advancing multi-wavelength photoelasticity through single-exposure detection

In this paper,we present a method to expedite multi-wavelength photoelasticity for efficient stress analysis.By modulating two slightly different-wavelength illumination beams and simultaneously capturing dark-field and bright-field images,our approach acquires four essential polarized images.Spatial filtering of Fourier transforms streamlines inner stress computation,enabling multi-wavelength photoelasticity with a single detector exposure.Theoretical foundations are outlined,and proof-of-principle experiments validate the feasibility with a measurement error below 6.4%.The high measurement speed,determined by the detector’s frame rate,facilitates dynamic sample measurements at video frequency,offering promising advancements in material stress analysis.