Reference surface calibration of a Fizeau interferometer through even/odd synthesis

Abstract

We propose an even-/odd-synthesis method for the elimination of additional aberration caused by misalignment or environmental vibration during the calibration of a Fizeau interferometer reference surface (RS). The odd and even parts of an RS can be obtained, because surface errors could be divided into rotationally symmetric and nonrotationally symmetric terms. We then propose a least-squares algorithm with a dual-objective optimization function for calibration of the measurement results at the confocal position. Finally, a complete RS can be eventually obtained by synthesizing the odd and even parts of the RS. It has been verified through experiments that the measurement repeatability of the PV value is better than 0.003λ, and the root-mean-square value is better than 0.0003λ.

Estimation of an uncertainty budget and performance measurement for a dual‐wavelength Twyman‐Green interferometer

“…Calibration of surfaces with high accuracy is needed for many applications in industry. [1][2][3][4][5][6][7][8][9][10][11][12][13] In some applications such as calibration of gauge blocks 14 and references of the interferometers, 15 it is of practical importance to estimate the uncertainty budget of the measurement result to verify the conformance of the components. 16 Optical interferometers have been extensively used as noncontact instruments for accurate surface measurement.…”