Compact digital holographic apparatus and method of particle field

Abstract

The invention relates to a digital holographic measurement technology of a particle field and aims to provide a compact digital holographic apparatus and method of a particle field. The apparatus comprises a laser source and a spatial filter, a collimating beam expander, a beam splitter and a first half transparent and half reflecting mirror which are sequentially arranged along the transmitting direction of the laser source, wherein the beam splitter, an attenuator and a second half transparent and half reflecting mirror are sequentially arranged in the direction vertical to the transmitting direction of the laser source; a totally reflecting mirror, the second half transparent and half reflecting mirror, an imaging lens and a CCD (charge coupled device) detector are sequentially arranged in the direction opposite to the transmitting direction of the laser source; the totally reflecting mirror corresponds to the first half transparent and half reflecting mirror; and the CCD detector is connected to a computer through a signal wire. The apparatus can conveniently control the recording plane of a hologram, and particularly can ensure the recording plane to be at the right side of the first half transparent and half reflecting mirror. The laser transmitting and CCD receiving can be arranged at the same side, so that a digital holographic system is compact and portable.

Description

technical field [0001] The invention relates to the digital holographic measurement technology of the particle field, in particular to a compact digital holographic device of the particle field and a method for obtaining a particle digital hologram based on the device. Background technique [0002] The development of the field of multiphase flow puts forward urgent requirements for full-field three-dimensional, transient and real-time particle field measurement technology. The holographic method is one of the important methods and has great development potential. The holographic technology simultaneously records the light intensity and phase information of the light scattered by the particles, so as to obtain the information of the position, particle size and velocity of the particles in the three-dimensional space, and has the characteristics of instantaneous freezing of the three-dimensional flow field and permanent preservation. Digital holography is a technology that us...

AI Technical Summary

Problems solved by technology

The Gabor mode is relatively simple, and the requirements for laser coherence are relatively low, but the laser emitting unit and the CCD receiving unit are coaxially arranged on both sides of the measured object, which can only be used for the measurement of small flow fields, and cannot be applied to relatively large industrial sites. Large scale flow field test

In addition, the Gabor mode also requires openings on both sides of the measured flow field. Therefore, the application of digital holography technology in the multiphase flow particle field, especially in the actual industrial flow field is limited.

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