2018/04/23 by Haowen Liang, Qiaoling Lin, Xiangsheng Xie +8 · 1 citation
Physics and Astronomy · #physics.optics
paper · pdf · doi:10.1021/acs.nanolett.8b01570
22 pages, 7 figures, an original journal paper
arxiv created 2018/04/23 · arxiv updated 2018/08/01
We demonstrate a metalens with NA = 0.98 in air, a bandwidth (FWHM) of 274 nm and a focusing efficiency of 67% at 532 nm wavelength, which is close to the transmission performance of a TiO2 metalens. Moreover, and uniquely so, our metalens can be front-immersed into immersion oil and achieve an ultra-high NA of 1.48 experimentally and 1.73 theoretically, thereby demonstrating the highest NA of any metalens in the visible regime reported to the best of our knowledge.