Measurement And Error Analysis Of Large Radius Optics

A new kind of measurement of large radius optics by using Fizeau interferometer has been studied in the paper.In this method,we use a transmission flat as a reference mirror instead of transmission sphere when testing and analysis the surface quality of sphere mirror.This experience shows that this method can effectively solve the problems caused by traditional method such as the difficult process of the reference mirror,the large space of measurement,the low measure accuracy.It's a useful noncontact,high precision method for measuring the large radius optics.In the method,the surface shape of large radius optics is first obtained by using Fizeau interferometer and the surface shape of a reference mirror is gotten by absolute testing and then these two surfaces to get the absolute surface of large radius optics including PV?RMS are dealed with.Since commercial software of interferometer can't meet the demand of measurement,we wrote the programs of collecting?unwrapping?Zernike decomposing and fitting to complete the measurement.We show the results with charts and figures.We still did some error analysis of measurement beside the measurement,including calibration error?absolute error?interferometer error and so on.By calculation,simulation and related experiments,we find that the reference's absolute test error and the calibration error play the main role.