Three-view-field digital holographic detection device and method based on two-dimensional period grating and point diffraction

Abstract

The invention relates to a three-view-field digital holographic detection device and method based on a two-dimensional period grating and point diffraction. The device comprises a light source (1) with emission wavelength lambda, a polarizer I (2), a collimating beam expansion device (3), a measurement window (4), a to-be-detected object (5), a first lens (6), a two-dimensional period grating (7), a hole array (8), a polarizer II (9), a polarizer III (10), a polarizer IIII (11), a second lens (12), a diaphragm (13), an image sensor (14) and a computer (15). View field translation and frequency domain separation are realized through two-dimensional period grating light splitting and carrier wave introduction, interference among three beams of object light can be avoided through the polarizer set, and crosstalk among frequency spectrum can be reduced. The device is advantaged in that the device is simple and easy and is convenient for adjustment, an image sensor view field utilization rate is high, the hologram carrier wave frequency mapping relationship is simple, easy determination is realized, through grating defocusing accurate control, system carrier wave frequency determination complexity is low, and efficiency of a phase recovery algorithm is high.

Description

Technical field [0001] The invention belongs to the field of digital holographic detection, and particularly relates to a three-field digital holographic detection device and method based on two-dimensional periodic grating and dot diffraction. Background technique [0002] On the basis of holography, digital holography uses CCD or CMOS as image collectors instead of holographic recording materials (such as holographic dry plates, etc.) to record digital holograms, and save the digital holograms in a computer. Diffraction propagation process realizes reconstruction imaging of digital hologram. As a new type of three-dimensional digital imaging technology, digital holography involves digitization in the recording and reconstruction imaging processes. Among them, off-axis holography uses the object light with a certain angle and the reference light to interfere, and the phase information of the object to be measured can be obtained from the formed single carrier frequency interfer...

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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