THz clock synchronization frequency modification continuous wave lossless thickness measurement detection system

Abstract

The invention discloses a THz clock synchronization frequency modification continuous wave lossless thickness measurement detection system, and aims at providing a terahertz thickness measurement imaging system that is simple in structure, stable, reliable, excellent in performance and capable of widely applied to multiple occasions, and can be used for performing lossless detection on special coating and structures in situ. The system is implemented via the technical scheme as follows: a clock module (1) generates two microwave drive signals synchronously inputting into a terahertz frequencymodification continuous wave transmission source (2) and a terahertz detector (3), to achieve synchronization of receiving and transmission clocks; and a polarized light path (4) performs polarizationon the terahertz signal, controls local oscillator modulation waveforms of the terahertz frequency modification continuous wave transmission source (2) and the terahertz detector (3), and thus the imaging radar with consistent terahertz frequency modification continuous wave receiving and transmission modulation waveforms and the ellipsometry frequency modulation continuous wave lossless detection thickness measurement system with inconsistent terahertz clock synchronization receiving and transmission modulation waveforms are achieved.

Description

technical field [0001] The invention relates to the field of non-destructive testing, and relates to a terahertz clock synchronous frequency modulation continuous wave non-destructive thickness measurement testing system, in particular to an imaging system for detecting material surface and internal defects based on non-contact surface morphology and internal defects. Background technique [0002] Terahertz wave is an electromagnetic radiation wave between infrared light and millimeter wave, because of its low photon energy, it is convenient for non-destructive testing, and it can penetrate non-metallic and non-polar substances that are opaque to most visible light and infrared light ( Such as paper, clothing and polyethylene, etc.) to detect hidden objects, and has broad application prospects in non-destructive testing, medical inspection, safety testing, environmental monitoring and space remote sensing. Compared with other electromagnetic bands, THz radiation has a series...

AI Technical Summary

Problems solved by technology

First, because the terahertz radiation energy is too weak, the penetration distance is very short

Second, it is necessary to measure the thickness by point-by-point spectrum measurement, resulting in a very slow speed

The advantage is that the imaging speed is very fast, and the disadvantage is that the thickness measurement accuracy is low

[0004] Then perform in-situ non-destructive testing on some special coatings and structural parts, such as special coatings on the surface of aircraft or special structural parts such as wings, whether it is THz-TDS (the traditional distance is too short, and the measurement speed is too slow) , or THz-FMCW (thickness measurement accuracy is insufficient, at the millimeter level), neither can meet the actual needs

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