Systematic error calibration of vertical dynamic interferometer with sloshing liquid plane

Abstract

Liquid mirror can calibrate the interferometer system error by measuring the surface of a steady-state, high-viscosity liquid; however, strict environmental safeguards are typically required. To address this problem, we propose a new liquid mirror method based on liquid micro-amplitude sloshing to calibrate dynamic interferometer system error. According to the multimodal analysis method of fluid finite amplitude sloshing, the liquid surface sloshing surface was modeled and analyzed, a time dimensional mean model was established, and the minimum sampling time was calculated. Finally, the error of the liquid surface sloshing was reduced by time averaging to realize the absolute calibration of the dynamic interferometer's systematic error. According to the proposed minimum sampling time theory, when the mean processing time is greater than the minimum sampling time, the error in the sloshing liquid surface can be controlled to within λ/100. The method’s correctness is proven through an experimental comparison of different calibration methods.