23 February 2018 Wavefront-aberration measurement and systematic-error analysis of a high numerical-aperture objective
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A two-dimensional (2-D) shearing interferometer based on an amplitude chessboard grating was designed to measure the wavefront aberration of a high numerical-aperture (NA) objective. Chessboard gratings offer better diffraction efficiencies and fewer disturbing diffraction orders than traditional cross gratings. The wavefront aberration of the tested objective was retrieved from the shearing interferogram using the Fourier transform and differential Zernike polynomial-fitting methods. Grating manufacturing errors, including the duty-cycle and pattern-deviation errors, were analyzed with the Fourier transform method. Then, according to the relation between the spherical pupil and planar detector coordinates, the influence of the distortion of the pupil coordinates was simulated. Finally, the systematic error attributable to grating alignment errors was deduced through the geometrical ray-tracing method. Experimental results indicate that the measuring repeatability (3σ) of the wavefront aberration of an objective with NA 0.4 was 3.4  mλ. The systematic-error results were consistent with previous analyses. Thus, the correct wavefront aberration can be obtained after calibration.
© 2018 Society of Photo-Optical Instrumentation Engineers (SPIE)
Zhixiang Liu, Zhixiang Liu, Tingwen Xing, Tingwen Xing, Yadong Jiang, Yadong Jiang, Baobin Lv, Baobin Lv, } "Wavefront-aberration measurement and systematic-error analysis of a high numerical-aperture objective," Optical Engineering 57(2), 024107 (23 February 2018). https://doi.org/10.1117/1.OE.57.2.024107 . Submission: Received: 13 November 2017; Accepted: 30 January 2018
Received: 13 November 2017; Accepted: 30 January 2018; Published: 23 February 2018

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