Optical metasurface fabricated using 3D nanoimprint lithography

To improve the performance of the next-generation optical metasurface device, we investigated the feasibility of practical design and fabrication processes for 3D optical metasurface. 3D nanoimprint lithography technology could duplicate the multilayer pattern of the device in a single fabrication process with high resolution, which shows the prospect of manufacturing the 3D optical metasurface. To verify the superiority of this method, we designed a novel multilayer optical metasurface 1-to-8 beam splitter, which could achieve high energy utility efficiency and light intensity distribution of the eight beams based on the principle of Dammann grating. The multilayer structure that we designed was prepared on a Si wafer. Then, the pattern could be duplicated by the 3D nanoimprint lithography. We also do the sensitivity analysis on how the fabrication errors influence the optical properties of the device. The analytical results show the fabrication process is robust. The sample we made with 3D nanoimprint lithography technology has a performance of 86.4% power efficiency and only 2.33% light intensity deviation. The high device performance and the low fabricating cost show that the 3D nanoimprint lithography technology is a solid way to manufacture the optical metasurface with complex structures.