  This paper proposed a novel and temporal phase-shift digital shearography
system for simultaneous measurement of first order displacement derivative in
orthogonal shear directions. Dual lasers with wavelengths of 532nm and 637nm,
three splitter prism structure, two dichroic mirrors with different response
wavelength, and the color CMOS are used in the system. Two dichroic mirrors can
be used as shear mirrors to realize shear in orthogonal directions at the same
time. The system realizes the measurement of the first-order displacement
derivative information in the orthogonal direction of the round metal aluminum
plate of diameter 250mm. The experimental results show that the overall
displacement integral PV error in the x and y directions is 2.7%-14.8%, which
verified the reliability of the system.
