Two-field digital holographic detection method based on one-dimensional periodic grating and point diffraction

Abstract

The invention provides a double-field digital holographic detection device and method based on a one-dimensional period grating and point diffraction and belongs to the field of digital holographic detection. The device comprises a light source with a wavelength of lambda, a linear polarization sheet I, a collimation and beam expanding device, a rectangular measurement window, a to-be-detected object, a first lens, a one-dimensional period grating, a hole array, a linear polarization sheet II, a linear polarization sheet III, a second lens, a diaphragm, an image sensor and a computer. According to the invention, translation of a field and separation of frequency domains are achieved via the functions of light splitting and carrier import of the one-dimensional period grating; the polarization sheet group can prevent interference of two object light beams, so that crosstalk between frequency spectrums can be reduced. The method is simple and easy to realize, and adjustment is convenient; the field utilization rate of the image sensor is high; the mapping relation of the carrier frequency of holograms is simple and determination is easy; accurate control can be achieved through a defocusing amount of the grating; the complexity of system carrier frequency is low and the efficiency of a phase retrieval algorithm is high.

Description

technical field [0001] The invention belongs to the field of digital holographic detection, in particular to a dual-field digital holographic detection device and method based on one-dimensional periodic grating and point diffraction. Background technique [0002] On the basis of holography, digital holography uses CCD or CMOS as an image collector instead of holographic recording materials (such as holographic dry plates, etc.) to record digital holograms, and saves digital holograms in computers. Diffraction propagation process to realize reconstruction imaging of digital hologram. As a new type of three-dimensional digital imaging technology, digital holography involves digitization in its recording and reconstructing imaging processes. Among them, off-axis holography uses the object light with a certain angle to interfere with the reference light, and the phase information of the object to be measured can be obtained from the formed single carrier frequency interferogra...

AI Technical Summary

Problems solved by technology

But its structural alignment is more difficult

[0006] It can be found that the current multi-field digital holographic detection technology generally has shortcomings such as difficult collimation and low utilization of CCD field of view.

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