We propose an iterative optimization approach for wavefront reconstruction in a rotational shearing interferometer based on Zernike polynomials. Two incorrect shearing amounts are optimized simultaneously, enabling the absolute reconstruction of wavefronts with high uniformity in the root mean square (RMS). Simulations under noisy conditions show that the reconstruction error, in terms of peak-to-valley (PV) and RMS, remains within the μλ range. The approach was experimentally validated by identifying asymmetric aberrations in an imperfectly collimated light source, showing strong agreement with the wavefront obtained from a Shack–Hartmann sensor.

Deflectometry is a non-destructive, full-field phase measuring method, which is usually used for inspecting optical specimens with special characteristics, such as highly reflective or specular surfaces, as well as free-form surfaces. One of the important steps in the Deflectometry method is to retrieve the surface from slope data of points on the sample map or surface reconstruction. This paper proposes a modal reconstruction method using an adjustable number of Zernike polynomials. In addition, the proposed method enables the analyses on practical surfaces that require an infinite number of Zernike terms to be represented. Experiments on simulated surfaces indicated that the algorithm is able to reveal the number of major-contributing Zernike terms, as well as reconstruct the surface with a micrometer-scale from slope data with a signal-to-noise ratio of 10.

A novel approach for wavefront reconstruction in rotational shearing interferometer is proposed. The correlation between the original and rotational wavefront is represented in matrix formalism, and the Zernike coefficient of the original wavefront is calculated from the interferogram wavefront through this matrix. We demonstrated the reconstruction ability of the method is efficient with negligible reconstruction errors by simulation. Experimental validation through the self-crosscheck property is introduced to indicate a uniform aberration of our collimator with high agreement.