内挿誤差の自律校正による干渉計の高精度化

抄録

Resolution of interferometers reaches to a few nanometers or less with the phase shifting or other interpolation techniques. However the accuracy of them could not approach to their resolution because any accurate standard for calibration could not be found. The present paper proposes a self-calibration method which can determine the interpolation error between fringes of the interferometer without using any standard. An interferometer of Michelson type has been developed with the phase shifting by a piezo electric actuator. The interpolation error due to the phase shifting actuator has been calibrated by the proposed self-calibration method. The reliability of the calibration result is estimated to be about 0.2 nm from the reproducibility error of the calibration. It has been confirmed that the proposed method can calibrate the interpolation error with the accuracy of the limit given by the resolution or the stability of the interferometer itself.