3D Printed Diffraction Gratings by Two-Photon Polymerization

Abstract

Abstract Diffractive optical elements (DOEs) are important optics that can manipulate the light by diffraction, which could be used in optical systems where compactness and lightweight matter. As one of the typical DOEs, diffractive gratings have widely application and their fabrication requires high precision and a clean environment. In this paper, we designed and fabricated diffraction gratings with different dimensions for visible light using the two-photon polymerization technique. The optical path differences and distances between diffraction fringes were measured and compared with the theoretical ones. The results showed that the precision across the printing direction was good while the height differences in the printing direction were around 20% smaller than the designed ones. Another problem was that the gratings were printed by small blocks and the borders of the blocks could serve as secondary gratings to generate smaller diffraction fringes, which need to be fixed for future fabrication of precise gratings and other complex DOEs by two-photon polymerization.