Interference weighted sampling phase solution analysis method and measurement system based on pre-analysis under arbitrary cavity length

Abstract

The invention discloses a pre-analysis based interferometric weighted sampling dephasing analysis method and measurement system under any cavity length. The multi-surface transparent measured component is a transparent parallel plate. By pre-analyzing the weighted multi-step dephasing algorithm, Store the available parameters, the corresponding cavity length coefficients and the phase-shifting reference coefficients necessary for the algorithm in the pre-analysis matrix of the algorithm library; when using this algorithm to solve the phase, the corresponding parameter values ​​in the algorithm library are directly called and automatically pass the distance measurement. The sensor measures the distance value from the measured part to the front surface of the reference mirror and the cavity length value, which breaks through the limitation of the fixed algorithm that can only be applied to the measurement under the fixed cavity length, and realizes the convenient design of the algorithm; the measuring system of the present invention It mainly includes a laser ranging sensor, a fixture combination and a matching device for a guide rail, and the fixture combination includes a fixture and a guide rail frame. The guide rail frame of the invention can assist the laser ranging sensor to realize the automatic measurement of the distance of the measured object, is easy to operate, and has high measurement accuracy.

Description

technical field [0001] The invention relates to an optical interference measurement method and device, in particular to an interference weighted sampling phase resolution analysis method and a measurement device, which are applied in the technical field of optical measurement technology. Background technique [0002] Optical interferometry technology is a measurement method based on the principle of light fluctuations that can achieve nanometer and sub-nanometer precision. It is recognized as the most accurate and effective non-contact method for detecting optical components and optical system related parameters. One of the measurement methods. In interferometry, the current mainstream measurement method is PZT (Piezoelectric Transducer, PZT) phase-shifting technology based on piezoelectric ceramics. This technology has been used for a long time and the technology is relatively mature. However, because hardware errors and mechanical stress errors will be generated during th...

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Problems solved by technology

Therefore, when using the multi-step phase-shifting algorithm for multi-surface interferometry, it is necessary to limit the setting of the cavity length coefficient and phase-shifting value. Often, an algorithm can only deal with one or a limited number of situations after it is designed. , when the cavity length coefficient changes, the dephasing and signal separation cannot be performed, which is one of the main difficulties of the current multi-surface dephasing technology based on multi-step phase shifting

[0006] At the same time, because the traditional algorithm design method does not pre-evaluate and analyze the algorithm, the specific scope of application of a multi-step phase resolution algorithm is generally unknown to the designer, and only one more or a limited number of methods can be obtained through experiments. Algorithm design and experimental formulation of this scheme greatly limit the application range of this algorithm

[0007] Not only that, but the traditional design methods are mostly based on discrete parameter design for algorithm application, but in the actual process, due to the limitation of experimental conditions, it is generally impossible to strictly meet the ideal conditions, so the algorithm needs to be tested according to known conditions during measurement. Fine-tuning, rather than comprehensive analysis of algorithms and estimation and storage of effective data fundamentally

[0008] In terms of hardware, the traditional method mostly uses a scale or a sliding rail with a scale to measure the distance of the tested part. large measurement error

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