Fig. 1. Schematic diagram of optical Fourier transform system modulated by aperture diaphragm and phase element

Fig. 2. Equivalent geometrical light path for modulated Fourier transform system and geometrical light path of light imaged on optical axis. (a) Equivalent geometrical light path; (b) geometrical light path of light imaged on optical axis

Fig. 3. Fourier transform system jointly modulated by aperture diaphragm and space-variant phase element. (a) Equivalent geometrical light path; (b) schematic diagram of aperture diagraphm imaged on space-variant grating; (c) schematic diagram of symmetric distribution for aperture diaphragm and grating pixel

Fig. 4. Schematic diagram of planar segmented micro-grating and inversely designed aperture diaphragms. (a) Schematic diagram of planar segmented micro-grating with three frequencies; (b)-(d) inversely designed aperture diaphragms for segmented micro-grating with three frequencies

Fig. 5. Light field distributions on Fourier spectrum plane and imaging plane. (a)-(c) Light field distribution on Fourier spectrum plane; (d)-(f) light field distribution on Fourier imaging plane

Fig. 6. Structural diagram of spatial orientation grating and schematic diagram of phase element with orientation-variant grating. (a) Structural diagram of spatial orientation grating; (b) schematic diagram of phase element with orientation-variant grating

Fig. 7. Inversely designed aperture diaphragms and light field distribution on Fourier imaging plane obtained by joint modulation of inversely designed aperture diaphragms and orientation-variant gratings. (a)-(c) Inversely designed aperture diaphragms; (d)-(f) light field distribution on Fourier image plane

Fig. 8. Ray tracing on Fourier imaging plane before and after Zemax optimization. (a) Before optimization; (b) after optimization

Fig. 9. Detected light field on Fourier imaging plane. (a)-(c) Light field on imaging plane modulated by segmented aperture diaphragms and gratings; (d)-(f) light field on imaging plane modulated by interleaved aperture diaphragms and orientation-variant gratings

Fig. 10. Sample pictures measured by 3D laser confocal microscopy and scanning electron microscopy. (a)-(c) Sample pictures (magnification of 20); (d) pixel measurement results of space-variant nanostructures; (e) scanning electron microscope image of nano-grating