Fabrication of micromodel grid for various moiré methods by femtosecond laser exposure

The femtosecond laser exposure system was used to fabricate model grids for the charge-coupled device (CCD) moiré method, scanning laser moiré method, and electron moiré method for microstrain deformation measurements. The femtosecond laser exposure produces mesoscopic variation patterns on the surface. These variation patterns make the grid in the scanning laser microscope and CCD images darker and make the grid in the scanning electron microscope image brighter. The CCD moiré fringe, scanning laser moiré fringe, and electron moiré fringe consisting of bright and dark lines were generated. As a demonstration, microstrain distribution of the three-point bending tested specimen was measured.