Fig. 1. Schematic of Gaussian beam incidence on onedimensional rectangular grating at angle θ

Fig. 2. Grating structure used in simulation and output optical field distribution and angular spectrum distribution under normal incidence of Gaussian beam.(a)Grating structure;(b)output optical field distribution;(c)angular spectrum distribution.

Fig. 3. Output optical field distributions and angular spectrum distributions when Gaussian beam with a half angle of 10°is incident on grating at±60°.(a)Optical field distribution at 60°incidence;(b)angular spectrum distribution at-60°incidence;(c)optical field distribution at-60°incidence;(d)angular spectrum distribution at 60°incidence

Fig. 4. Real spatial and angular spectral distributions after synthetic aperture.(a)Schematic of synthetic aperture with multi-angle illumination;(b)real spatial distribution after synthetic aperture;(c)angular spectrum distribution after synthetic aperture

Fig. 5. Grating structure obtained with synthetic aperture and structure of grating sample used in actual simulation

Fig. 6. Influence of the number of harmonics on calculation accuracy of output optical field under different grating periods

Fig. 7. Structure comparison between grating itself and reconstructed grating with different number of modes.(a)2 modes;(b)3 modes;(c)10 modes

Fig. 8. Effects of different parameters on 0 order diffraction efficiency.(a)Effect of grating period;(b)effect of grating depth;(c)effect of refractive index of grating material

Fig. 9. Angular spectrum distribution and grating structure after synthetic aperture imaging when 532 nm beam illuminates grating with 270,268 and 266 nm period at incident angle about 90°.(a)Angular spectrum distribution;(b)grating structure after synthetic aperture imaging

Fig. 10. Diffraction waves of 1st,2nd and 3rd orders fading with the increase of propagation distance for 532 nm beam illuminating 280 nm periodic grating

Fig. 11. Grating structure after synthetic aperture imaging for 532 nm beam illuminating grating with line width of 135,133 and 131 nm.(a)Line width of 135 nm;(b)line width of 133 nm;(c)line width of 131 nm