Enhancement of vibration desensitising capability of iterative algorithms for phase-shifting interferometers. (November 2017)

• Record Type: Journal Article
• Authors: Liu, Qian; Yuan, Daocheng; He, Huabin
• Is Part Of: Optics and lasers in engineering. Volume 98(2017)
• Page Start: 31
• Page End: 36
• Publication Date: 2017-11
• Subjects: Metrology -- Phase-shifting interferometry -- Iterative algorithm -- Vibration desensitisation; Lasers in engineering -- Periodicals; Optical measurements -- Periodicals; Optics -- Periodicals; Lasers en ingénierie -- Périodiques; Mesures optiques -- Périodiques; Optique -- Périodiques; 621.36605
• DOI: 10.1016/j.optlaseng.2017.05.020
• Languages: English
• ISSNs: 0143-8166

Abstract

Highlights: A novel method is proposed to enhance vibration-desensitization for PSI. Subsampling is employed to implement the method and shorten calculation time. The proposed method is proved effective and compatible by simulation and experiment. RMS error of the reconstructed surface with the proposed method is 1.75 nm. Abstract: The sensitivity of phase-shifting interferometers (PSIs) to vibration impairs their application in unsteady environment. Iterative algorithms were developed to desensitise the effect of vibration on PSIs, but their desensitising capability is restricted by the estimated initial value. In this paper, a spatial carrier-assisted method is proposed, in which a wavefront phase retrieved from an additional spatial-carrier interferogram is used as the initial value. Because of the benefits of spatial carrier, vibration immunity and sign determination, iteration could converge to accurate value even when interferometers are under severe vibration. To reduce the possibility of transverse movement of the measured surface, subsampling strategy is further proposed to decrease the required tilt angle, with the additional benefit of decreasing the calculation time of iteration. Computer simulations and experiments are performed to verify the effectiveness of the proposed method. Results indicate that the vibration desensitising capability of an iterative algorithm is significantly enhanced by the proposed method. The proposed method improves the vibration desensitising capability with low cost and is thus highly compatible.