Fig. 1. Schematic of linear zone plate. (a) Traditional linear zone plate (TLZP); (b) equal-width single-mode slit waveguide linear zone plate (ESSWLZP)

Fig. 2. Schematic diagram of equal-width single-mode slit waveguide linear zone plate

Fig. 3. Schematic of slit waveguide structure

Fig. 4. Theoretical and simulated fundamental mode normalized light field distribution in x direction of a single slit in the equal-width single-mode slit waveguide linear zone plate. (a) λ=5 nm; (b) λ=13.5 nm; (c) λ=40 nm

Fig. 5. Theoretical and simulated normalized far-field light field distribution of a single slit in the equal-width single-mode slit waveguide linear zone plate at the wavelength of 13.5 nm

Fig. 6. Normalized far-field intensity distribution of the equal-width single-mode slit waveguide linear zone plate(ESSWLZP) and traditional linear zone plate(TLZP) at the wavelength of 13.5 nm

Fig. 7. Schematic of multilevel equal-width single-mode slit waveguide linear zone plate, the solid line represents a periodic region, the dashed line represents the boundary of each level.(a) 2-levels structure; (b) 4-levels structure