Fizeau interferometer hysteresis error elimination method

Abstract

The invention relates to a Fizeau interferometer hysteresis error elimination method. A system employed by the method comprises a Fizeau interferometer, a reference mirror, a detected mirror, a reference mirror adjustment rack and a detected mirror adjustment rack. The hysteresis error elimination is achieved by adjusting the reference mirror adjustment racks for two times and adjusting the detected mirror adjustment racks for two times and by averaging four measurement results; and moreover, a carrier strip loading frequency value is used as a basis of quantitative adjustment of the referencemirror adjustment rack and the detected mirror adjustment rack, arbitrary carrier frequency measured by carrier can be achieved for actual measurement, and the system has the advantages of high accuracy, quantitative adjustment and high universality.

Description

technical field [0001] The invention relates to the field of interferometric measurement, in particular to a method for eliminating the return error of a Fizeau interferometer. Background technique [0002] It is generally believed that the Fizeau interferometer has the characteristics of a common optical path, that is, the reference light returned by the reference mirror and the measurement light returned by the measured mirror go through the same path inside the interferometer, and the interference optical path difference is only determined by the reference mirror and the measured light. caused by the mirror. But in fact, this state is only satisfied when the interference fringes are zero fringes, especially when there are carrier fringes in the interferometer, the reference light and the measurement light will also have an optical path difference inside the Fizeau interferometer, which is called the return error. When there are dozens of interference fringes, the return ...

AI Technical Summary

Problems solved by technology

This method ignores the influence of the reference mirror and the measured mirror on the optical path. In some high-precision measurement applications, it cannot meet the needs of backhaul error elimination.

[0008] In addition, companies such as Zygo and ESDI all use the form of pseudo interference fringes to assist operators to adjust the reference mirror or mirror under test to a specific amount of carrier fringes. Although pseudo interference fringes are more intuitive, they are not quantitative enough; The interferometer defaults to different carrier fringe densities, limiting the versatility of the cancellation method

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