Fast and high-precision phase recovery method for anti-vibration interferometry

Abstract

The invention discloses a fast and high-precision phase recovery method for anti-vibration interferometry, comprising: taking a certain row and a certain column of data in an interferogram to obtain two sets of one-dimensional interference signals; Optimization model; calculate the initial value of the tilt parameter of the one-dimensional interference signal; use the alternate iteration optimization model to alternately iterate the one-dimensional interference signal to obtain the corresponding tilt parameter of the one-dimensional interference signal; calculate the original two-dimensional interferogram according to the one-dimensional tilt parameter. The tilt parameter of the vibrating tilted plane; the phase information of the original interferogram is solved by the least squares solution phase method. The present invention has high phase recovery accuracy and fast iterative convergence speed for the conditions of large vibration inclination amplitude, small number of fringes, closed fringes and non-closed fringes, and non-uniform background and modulation degree, and does not require hardware for the interferometric measurement system. The modification provides a low-cost, high-precision solution for phase-shifting interferometry in vibration environments.

Description

technical field [0001] The invention belongs to the field of optical interferometric measurement, in particular to a fast and high-precision phase recovery method for anti-vibration interferometric measurement. Background technique [0002] Nowadays, optical interferometry technology is widely used to measure the surface shape of optical components, and phase-shifting interferometry technology has become the most important measurement method in interferometry due to its high precision. During phase-shift interferometry, a phase shifter is usually used to generate a phase shift of 2π / N between interferograms, where N is greater than or equal to 3. However, in actual measurement, the vibration of the external environment will cause random tilt errors in the phase shift amount, resulting in different phase shift amounts at different positions in the same interferogram, thereby reducing the accuracy of the measurement results. [0003] In order to recover the measured phase fro...

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Problems solved by technology

However, most of the existing iterative methods use the mathematical approximation of the first-order Taylor expansion to establish the linear least squares iterative model, or use the nonlinear least squares method to iterate. This kind of iterative method has mathematical approximation errors and is easy to fall into local optimum. solution, resulting in the interferogram that can only handle small vibration tilt amplitudes

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