Fig. 1. Principle diagram of Ronchi lateral interferometer setup used for wavefront aberration test of projection lens

Fig. 2. Shear ratio model of the Ronchi shearing interferometry system

Fig. 3. Data processing flow based on the high-precision shear phase extraction algorithm

Fig. 4. Interference field obtained by simulation when the phase-shift is 0

Fig. 5. Ideal shear phase

Fig. 6. Shear phase (left) extracted by different phase extraction algorithms and the shear phase extraction error (right). (a)(b) 10-step phase-shift algorithm; (c)(d) 13-step phase-shift algorithm; (e)(f) proposed high-precision phase extraction algorithm

Fig. 7. RMS shear phase extraction relative error due to grating period relative error

Fig. 8. Simulation results of RMS shear phase extraction relative error for different stage positioning errors

Fig. 9. RMS shear phase extraction relative error due to vibration error. (a) Amplitude variation; (b) vibration frequency variation

Fig. 10. Experimental setup of the double-grating Ronchi lateral shearing interferometry

Fig. 11. Based on the 25 phase-shift interferograms clipped in the x-direction collected by the proposed high-precision shear phase extraction algorithm, the phase-shift interferograms labeled with red dots are used in the 13-step phase-shift algorithm

Fig. 12. Results of shear interferometric experimental data processing for the proposed high-precision shear phase extraction algorithm. (a) x-direction; (b) y-direction

Fig. 13. Experimental data processing results of shear interferometry with 13-step phase-shift algorithm. (a) x-direction; (b) y-direction

Fig. 14. Results of wavefront reconstruction on the shear phase extracted data. (a) Wavefront reconstruction results of the proposed high-precision shear phase extraction algorithm; (b) wavefront reconstruction results of the 13-step phase-shift algorithm

Fig. 15. Experimental setup of the point diffraction interferometer

Fig. 16. Measurement result based on point diffraction interferometer