A Method of Improving the Alignment Accuracy of the Starting Point of pzt Phase Shift Modulation in Multi-wavelength Interferometry
A technology of interferometry and phase shift modulation, applied in the direction of measuring devices, instruments, optical devices, etc., to achieve the effects of reducing errors, improving precision, and high alignment accuracy
Inactive Publication Date: 2019-04-09
HUBEI UNIV OF TECH
View PDF5 Cites 0 Cited by
- Summary
- Abstract
- Description
- Claims
- Application Information
AI Technical Summary
Problems solved by technology
Its purpose is to improve the consistency of the starting point of phase modulation of different wavelengths, thereby improving the measurement accuracy
Method used
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View moreImage
Smart Image Click on the blue labels to locate them in the text.
Smart ImageViewing Examples
Examples
Experimental program
Comparison scheme
Effect test
Embodiment Construction
[0016] In order to facilitate those of ordinary skill in the art to understand and implement the present invention, the present invention will be described in further detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the implementation examples described here are only used to illustrate and explain the present invention, and are not intended to limit this invention.
[0017] please see figure 1 A method for improving the alignment accuracy of PZT phase-shift modulation starting point in a kind of multi-wavelength interferometry provided by the present invention comprises the following steps:
[0018] Step 1: Use PZT to achieve phase shift to get λ 1 ,λ 2 ,λ 3 Three wavelength interference patterns;
[0019] In this embodiment, the driving method of the PZT to realize the phase shift may be a "bow" path, or other methods.
[0020] Step 2: Obtain the initial phase of the coarse alignment of each wavelength according to ...
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More PUM
Login to View More Abstract
The invention discloses a method for improving PZT phase shift modulation starting point alignment precision in multi-wavelength interferometry. In multi-wavelength interferometry for a PZT to realize a phase shift, aiming at the problem of inconsistency of measurement starting point positions of various wavelengths brought by nonlinearity and hysteresis of the PZT, phase shift starting point positions need to be aligned, the starting point alignment precision of an existing method is not high, and a measurement result is affected. On the basis of rough alignment, and zero-order interference fringe points satisfying the following three conditions at the same time are searched: the single-wavelength initial phase is very small, near wavelength phase difference is very small and far wavelength phase difference is very small. According to the points on zero-order interference fringes that are found, an algorithm is utilized to perform further fine alignment on initial phases of various wavelengths in rough alignment, and high-precision alignment of phase shift starting point positions of various wavelengths is realized, thereby improving measurement precision. A measuring error brought by not high initial phase alignment precision in the multi-wavelength interferometry process is avoided, thereby greatly improving the precision and reliability of a subsequent measuring result.
Description
technical field [0001] The invention belongs to the technical field of multi-wavelength interferometry, and in particular relates to a method for improving the alignment accuracy of each wavelength at a phase-shift starting point in multi-wavelength alternate PZT phase-shift modulation interferometry. Background technique [0002] Among the methods of measuring the surface topography of objects, micro-interferometry has always been one of the popular methods. After comparing the results of single-wavelength interferometry and multi-wavelength interferometry, it is found that multi-wavelength interferometry can not only expand the range of measurement depth, but also use multi-wavelength interferometry to correct single-wavelength measurement results, thereby reducing measurement errors . [0003] When using multi-wavelength interferometry, the most widely used method is to use PZT to realize phase shift modulation. However, due to the nonlinearity of PZT driving and the cha...
Claims
the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More Application Information
Patent Timeline
Login to View More Patent Type & Authority Patents(China)
IPC IPC(8): G01B11/24
CPCG01B11/2441
Inventor 翟中生周立王选择吕清花张艳红程壮杨练根
Owner HUBEI UNIV OF TECH