Abstract:

In the Phase Shifting Interferometer, the lineal and non-lineal phase shifting deviation is the main factor influencing the phase accuracy. On the basis of the study on measurement errors caused by phase shifting deviation, this paper puts forward a novel technology compensating the phase shifting error. The data resulting from the five steps method are corrected using the method which estimates the deviation of the phase shifting device. The experimentation proves that the combination of 10% lineal and 1% non-lineal phase shifting errors will produce 0.12 radian of phase error, and the results will be decreased to 0.02 radian using the phase compensation method presented in this paper, which means the displacement error can be reduced to 1.0 nm from 6.0 nm in the double pass interferometer with stabilized 632.8nm He-Ne laser.

Key words: phase-shifting, nanometrology, inter ferometry, error compensation