Planar efficient metasurface for generation of Bessel beam and super-resolution focusing

In this paper, we propose a device generating Bessel beam that can assist microscope to enhance resolution of microscope to λ/3. As the conventional optical devices of generating Bessel beam have some drawbacks, such as low efficiency, and bulky volume, we design plane-axicons for generating Bessel beam using the principle of phase superposition. The designed plane-axicons can generate Bessel beams with zero-order and higher-order by changing topological charge n. We also demonstrate the FWHMs of plane-axicons about as small as λ/3 and have FWHMs with weak fluctuations independent of wavelength across the visible spectrum, which means the Bessel beam can be used to increase resolution of microscope. These performances make the plane-axicons can also enable other advanced research and applications related to Bessel beams ranging from laser fabrication to optical manipulation.