Interferometer displacement measurement system and method

Abstract

The invention provides an interferometer displacement measurement system and method. The system comprises the steps that: measurement light returns to a first photoelectric detector and a second photoelectric detector after being processed by a first polarization splitting prism, a first 1 / 4 wave plate, a first splitting prism, an optical waveguide assembly and a reflection device; reference lightreturns to the first photoelectric detector and the second photoelectric detector after being processed by a second polarization splitting prism, a second 1 / 4 wave plate, a second splitting prism anda reflector; the first photoelectric detector forms a measurement signal according to the processed measurement light and reference light, and the second photoelectric detector forms a reference signal according to the processed measurement light and reference light; and displacement information of a to-be-detected object is determined according to the measurement signal and the reference signal.With the system and method of the invention adopted, the displacement measurement error can be reduced, and the measurement precision and the measurement range are improved.

Description

technical field [0001] The invention relates to the technical field of precision displacement measurement, and more specifically, to an interferometer displacement measurement system and method. Background technique [0002] Precision measurement is the basis of precision processing, especially for IC equipment, nanometer or even sub-nanometer resolution has become the standard and requirement of precision measurement. At present, laser interferometer and grating interferometer are the research objects of precision measurement. requirements are also getting higher. [0003] However, in the actual displacement measurement process, due to the movement of the object and other factors, the grating or the mirror will produce a small rotation angle. Since there are stripes in the interference spot range, the photodetector is directly used to detect the interference spot, and the signal quality will be relatively poor. At present, the method to solve the problem of poor signal qua...

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Problems solved by technology

[0005] In view of the above problems, the object of the present invention is to provide an interferometer displacement measurement system and method to solve the problems of the current interferometers such as large volume, poor detection quality, low accuracy, and small application range.

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