Holographic Aberration Absolute Calibration Method and System Based on Shift and Polynomial Fitting

Abstract

The invention relates to a digital holographic microscope aberration absolute calibration method and system based on sequential shifting and Chebyshev polynomial fitting, and belongs to the field of optical measurement. The method comprises the steps of orthogonally moving a sample twice after a first hologram is collected and separately capturing holograms of the sample, thus acquiring three holograms; performing phase modulation on the holograms to acquire three original phase results; performing coordinate conversion on the results, thus enabling the converted test object to have a coherentphase; performing differential computation to acquire phase differential data of a system aberration phase before and after two displacements; computing a Chebyshev polynomial coefficient and thus computing the system aberration phase; and subtracting the system aberration phase from the acquired original phase results including aberration to acquire the phase of the test object. According to themethod and system provided by the invention, the medium-high frequency information of the object phase can be effectively protected, the requirement on setting of light paths is low, and the system aberration compensation can be performed on the random traditional digital holographic microscope imaging system by only needing an additional triaxial displacement platform.

Description

technical field [0001] The invention relates to a digital holographic microscope aberration absolute calibration method and system based on sequential displacement and Chebyshev polynomial fitting, belonging to the technical field of optical measurement. Background technique [0002] Digital holographic microscopy is a non-destructive, label-free and interferometric quantitative phase-contrast technique that has had a huge impact in many fields such as biology, neuroscience, nanoparticle tracking, microfluidics and metrology. Like other traditional interference systems, the digital holographic microscope system also has system phase distortion, which is mainly introduced by the aberration of the microscope objective lens and other optical components and the system adjustment error. Typically, systematic phase aberrations are superimposed on the sample phase information and need to be compensated for. [0003] Recently, many physical and numerical methods have been proposed ...

AI Technical Summary

Problems solved by technology

The calculation functions and algorithms used are different, and the error of the method itself is also different. The application conditions, that is, the types of aberrations that the method can eliminate and the preconditions for the use of the method are also different. Some methods even lose information themselves, such as using The background fitting method requires that the proportion of the background is much larger than that of the test sample, and the method of using filtering to achieve compensation will inevitably lose the information of the target object, etc.

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