Generation of 13.5-nm Bessel Beams Using Metasurfaces

In this paper, a metalens generating 13.5-nm Bessel beam for extreme ultraviolet (EUV) application is proposed. The beam intensity profile at different NA are demonstrated, and the simulation results are in agreement with the theoretical values. Such a metalens with NA of 0.045 can generate Bessel beam with depth of focus, beam FWHM of 120 μm and 106.5 nm, respectively. These properties make it promising for applications in important fields such as lithography and microscopy.