Research on Femtosecond Laser Etching of Cylindrical Encoding Gratings
The measurement accuracy of cylindrical coded grating is directly determined by the grating line precision.In this paper,high precision micrometer grating lines are obtained by etching cylindrical grating with femtosecond laser.The line width of 6 μm was realized by optimizing laser power,scanning times,repetition frequency and other parameters.The imaging effect of different depth of engraving in the imaging system of paraxial light source is analyzed.Finally,grating lines with complete fringe and distinct contrast between light and dark fringe are obtained.