System and method for improving terahertz wave nondestructive testing resolution

Abstract

The invention discloses a system and a method for improving terahertz wave nondestructive detection resolution, and belongs to the technical field of detection. An optical element is added behind a terahertz wave focusing element to generate a quasi-zero-order Bessel wave beam from a collimated Gaussian wave beam so as to achieve relatively long depth of field and relatively high resolution in terahertz wave imaging. A confocal technology is adopted to meet a large dynamic range and a high signal-to-noise ratio, and the system comprises a terahertz wave transmitting end, a terahertz wave receiving end and a laser displacement sensor used for measuring the distance between the terahertz wave transmitting end and a detection area and the distance between the terahertz wave receiving end andthe detection area. The directions of terahertz waves in the terahertz wave transmitting end and the terahertz wave receiving end are different from each other; the terahertz wave transmitting end projects terahertz waves to the detection area, and the terahertz wave receiving end receives the terahertz waves from the detection area; the terahertz wave transmitting end and the terahertz wave receiving end each comprise a focusing element used for terahertz wave focusing and an optical element used for generating a quasi-zero-order Bessel beam.

Description

technical field [0001] The invention belongs to the technical field of detection, and in particular relates to a system and method for improving the resolution of terahertz wave non-destructive detection. Background technique [0002] The statements herein merely provide background information related to the present invention and do not necessarily constitute prior art. [0003] Terahertz waves refer to electromagnetic waves with frequencies in the range of 0.1THz to 10THz and corresponding wavelengths between 3mm and 0.03mm. Like visible light, X-rays, infrared and ultrasound waves, terahertz waves can also be used to image objects. Since terahertz waves can penetrate non-metallic and non-polar materials such as ceramics, graphite, polymer composites, plastics, and foams, it is possible to detect defects, holes, inclusions, debonding, and faults in samples made of these materials. Clear imaging of dislocations and cracks, etc., to achieve non-destructive testing. Compare...

AI Technical Summary

Problems solved by technology

[0004] The inventors found that most of the traditional terahertz wave imaging detection technologies are based on Gaussian beams, and it is difficult to have a long depth of field and high resolution. Even if the terahertz wave structured beams appear, they all use a single channel. There are problems such as small dynamic range and low signal-to-noise ratio

Images