Fig. 1. Schematic diagram of PIE with highly tilted illumination. (a) Optical path schematic; (b) flowchart of the algorithm

Fig. 2. Diffraction patterns with different incident angles. (a) Diffraction pattern calculated by spherical wave integration based on Huygens-Fresnel principle with large incident angle; (b) diffraction pattern calculated by the revised angular spectrum with the same incident angle; (c) diffraction pattern when the incident angle is 3°; (d) diffraction pattern when the incident angle is 0°

Fig. 3. Simulated initial value. (a) Amplitude of specimen; (b) phase of specimen; (c) amplitude of probe light; (d)phase of probe light

Fig. 4. Representative 9 diffraction patterns of dataset

Fig. 5. Reconstructed results based on general ePIE algorithm with highly tilted illumination after 500 iterations. (a) Amplitude of specimen; (b) phase of specimen; (c) amplitude of probe light; (d) phase of probe light

Fig. 6. Reconstructed results based on revised angular spectrum and ePIE after 500 iterations. (a) Amplitude of specimen; (b) phase of specimen; (c) amplitude of probe light; (d) phase of probe light

Fig. 7. Error curves corresponding to the two calculation methods

Fig. 8. Reconstructed results at the angle errors from -1.5° to 1.5°. (a) Reconstructed amplitude of probe light; (b) spectrum intensity of probe light; (c) amplitude of specimen; (d)error curve with the change of different angle errors

Fig. 9. Part of diffraction patterns recorded by CCD, in which the coordinates represent the position information among the grid of 10×10

Fig. 10. Experimental results based on revised angular spectrum and ePIE with highly tilted illumination. (a) Amplitude of specimen; (b) phase of specimen; (c) amplitude of probe light; (d) phase of probe light

Fig. 11. Experimental results based on general ePIE algorithm with highly tilted illumination. (a) Amplitude of specimen; (b) phase of specimen; (c) amplitude of probe light; (d) phase of probe light

Fig. 12. Experimental error curves corresponding to the two calculation methods

Fig. 13. Experimental results of USAF 1951 test target. (a) Reconstructed results with the proposed algorithm; (b) locally enlarged view of Fig. 13 (a); (c) reconstructed results with the traditional ePIE algorithm; (d) locally enlarged view of Fig. 13 (c)