Three-dimensional terahertz tomography system, scanning method and image reconstruction method thereof

Abstract

The invention discloses a three-dimensional terahertz tomography system, a scanning method and an image reconstruction method thereof. The three-dimensional terahertz tomography system comprises a terahertz emitting source, a wave chopper, a sample rotation translation table, a light beam transmission unit, a terahertz detector and a lock-in amplifier. The imaging method comprises a scanning method for acquiring projection data and an image reconstruction method. According to the present invention, when a sample is scanned by the imaging system, only the single-frequency transmitted light intensities of each detection point are required to be recorded, such that the imaging time is reduced, and the power is high so as to image the thick object; when the image reconstruction is performed according to the projection data, the absorption rate distribution of the sample at the angle according to the projection data at each angle is obtained, and the absorption rate distribution and the terahertz light beam light intensity distribution are subjected to deconvolution, such that the actual absorption rate distribution of the sample can be obtained; and with the imaging method and the system of the present invention, the problem that the light approximation on the terahertz light beam can cause the blurred image in the existing imaging technology can be effectively solved.

Description

technical field [0001] The invention belongs to the technical field of terahertz imaging, and more specifically relates to a three-dimensional terahertz tomographic imaging system and scanning and image reconstruction methods. Background technique [0002] X-ray computer tomography (CT) can perform three-dimensional imaging on dense materials such as human body, biological tissue, and steel, and is used to detect internal diseases in the human body and internal defects in industrial parts, but X-rays can cause harmful ionization reactions, resulting in radiation Damage; low-density materials such as plastics, paper, and coatings have too low absorptivity for X-rays, and general-purpose X-ray tomography systems cannot identify defects and cracks in these materials; these inherent defects limit the popularization and promotion of X-ray CT . [0003] Electromagnetic waves in the terahertz frequency range not only have good penetrating properties to dielectric materials, but al...

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Problems solved by technology

[0004] In view of the above defects or improvement needs of the prior art, the present invention provides a three-dimensional terahertz tomography system and a scanning and image reconstruction method, the purpose of which is to solve the problem of image distortion caused by uneven light intensity distribution in terahertz imaging

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