Terahertz suppression fringe interference imaging method and system based on complex field circle construction method

Abstract

The invention relates to a terahertz suppression fringe interference imaging method and system based on a complex field circle construction method. Comprising a terahertz transceiver, a focusing light path lens assembly, an imaging object, a three-dimensional displacement table and an electronic computer. Terahertz waves are emitted by the transceiver, are refracted by the focusing light path lens assembly, are irradiated to an imaging object, are reflected by the imaging object, are returned by an original light path and are focused to a focus, and the terahertz transceiver at the focus receives signals and measures the intensity and phase of the signals. After an imaging object is imaged for multiple times at different specific positions along an optical axis, a plurality of complex value images are obtained. And estimating background clutter signals of the complex value image through a complex domain upper circle construction method and removing the background clutter signals so as to restore the image. According to the method, background clutter signals can be well estimated through a small number of images, the clear and stripe-free terahertz image is obtained, the method is superior to a traditional average value method and a background elimination method, and better terahertz image stripe noise removal is achieved.

Description

technical field [0001] The invention relates to the field of terahertz imaging, in particular to a terahertz suppression fringe interference imaging method and system based on a complex domain circle construction method. Background technique [0002] Terahertz waves refer to electromagnetic radiation with frequencies in the 0.1-10THz frequency band. Terahertz waves have a series of unique characteristics due to their special position in the electromagnetic spectrum, and have been widely used in biomedical detection, material property detection and other fields. For example, terahertz photons have low energy and non-ionizing properties, and can achieve non-destructive testing; terahertz has the ability to penetrate many non-metallic materials and can be used for concealed object detection in security inspections. However, unwanted fringe interference is often present in the obtained THz intensity images. The fringe interference will reduce the clarity of the imaging image a...

AI Technical Summary

Problems solved by technology

However, in the actual detection environment, it is often difficult to obtain background information in advance

The average method can effectively suppress background clutter by taking the average value of multiple measurements, but requires more measurements

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