Phase lenses and mirrors created by laser micronanofabrication via two-photon photopolymerization

The phase lens, also called kinoform, a promising focusing component in an integrated micro-optical system, was produced by femtosecond laser fabrication via two-photon photopolymerization. Kinoforms consisting of two-, four-, eight-level subzones with level thicknesses of 475, 238, and 119nm demonstrate diffraction efficiencies of 30%, 54%, and 68%, respectively, which are comparable with the theoretical limit and with those from the commercial phase lenses. In addition, a reflective diffractive micromirror was proposed and realized with the aid of electroless plating. These works show the promising prospect of femtosecond laser fabrication in manufacturing optical micronanodevices and their integrated system with optical quality.