Absolute measurement of flats with the method of shift-rotation

摘要

We present an absolute measurement of flats in a Fizeau interferometer with the method of shift-rotation, which only requires rotational measurements and shift measurement with a translation. Experiments have been carried out to verify the validity of the absolute testing method, and the results show that the reference surface deviation measured with the shift-rotation method agrees well with that of another calibration result with traditional three-flat absolute procedure; the root-mean-square (RMS) of the residual figure between them is ～0.4 nm.