Fig. 1. Schematic diagram of optical system

Fig. 2. Schematic diagram of the nano-pillar unit and the relationship between its rotation angle and related parameters. (a) Schematic diagram of a single nano-pillar unit; (b) relationship between the rotation angle of the nano-pillar unit and the transmittance(triangular line),polarization conversion efficiency(circular line), PB phase(square line)

Fig. 3. Schematic diagram of hyperbolic phase metasurface and light field distributions. (a) Three-dimensional schematic diagram of the hyperbolic phase distribution metasurface; (b) light field distribution of the metasurface along the beam propagation direction; (c) focal plane light field distribution of the metasurface along the beam propagation direction

Fig. 4. Schematic diagram, light field distribution and phase curves of the metasurface with an annular obstacle added. (a) A three-dimensional schematic diagram of the metasurface with the annular obstacle added; (b) optical field distribution of the outer ring part of the metasurface (radius R₃) along the beam propagation direction; (c) focal plane light field distribution of Fig.4 (b); (d) hyperbolic phase and conical phase comparison chart, where the blue dotted line is the hyperbolic phase distribution, the solid line is the conical phase distribution, and the inset is an enlarged view of the two phase distributions in a radius of 10~12 μm

Fig. 5. Schematic diagram, light field distribution and linear distribution of the metasurface with ring-shaped obstacle added. (a) A two-dimensional schematic diagram of the metasurface with the annular obstacle added; (b) optical field distribution of the spherical wave generated by the inner ring; (c) optical field distribution of the Bessel light generated by the outer ring; (d) optical field distribution of the array local hollow beam; (e) linear distribution of spherical wave in Fig.5(b); (f) linear distribution of Bessel light in Fig.5(c); (g) linear distribution of the multiple hollow beam in Fig.5(d)

Fig. 6. Multiple bottle beam light field diagram and linear diagram. (a) Optical field distribution in the beam propagation direction of the multiple bottle beam; (b) (c) optical field distribution at 9.45 μm and 11.54 μm; (d) linear distribution of Fig.6(a), in which the longitudinal FWHM of the two hollow beams are 0.9 μm and 1.2 μm, respectively; (e)(f) linear distribution of Fig.6(b) and Fig.6(c), and their transverse FWHM are 0.47 μm and 0.61 μm, respectively

Fig. 7. Influence of different relative aperture values on the light field of local hollow beam. (a) A two-dimensional optical field distribution diagram of an array local hollow beam with different RA along the beam propagation direction; (b) linear fit of different RA and transverse FWHM; (c)linear fitting of different RA and radial FWHM

Fig. 8. Two-dimensional light field distribution diagrams of a metasurface with different apertures of an annular obstacle along the beam propagation direction. (a) R₂=5 μm; (b) R₂=6 μm; (c) R₂=7 μm