scholarly journals Nondestructive Internal Defect Detection Using a CW–THz Imaging System in XLPE for Power Cable Insulation

2020 ◽  
Vol 10 (6) ◽  
pp. 2055 ◽  
Author(s):  
In-Sung Lee ◽  
Joong Wook Lee
Keyword(s):  
Nondestructive Testing ◽  
Continuous Wave ◽  
Imaging System ◽  
Electrical Power ◽  
Coherent Detection ◽  
Power Cable ◽  
Thz Imaging ◽  
Cable Insulation ◽  
Detection Scheme ◽  
Thz Waves

The demand for internal nondestructive testing and inspection techniques is rapidly increasing. Using a continuous wave (CW) terahertz (THz) imaging system, we demonstrate that the internal defects in cross-linked polyethylene (XLPE) plates for power cable insulation can be detected. In a coherent detection scheme based on photomixers, which serve as the THz emitters and receivers, the change of phase occurring with the defects inside the XLPE plates is distinctly measured by the change in the amplitude of the transmitted THz waves. According to the two-dimensional images of THz waves transmitted through the XLPE plates, defects of up to 0.5 mm size located inside the XLPE plates can be detected by the internal nondestructive examination method based on CW–THz waves. This technique will be useful for internal nondestructive testing and inspection of insulation materials that require high resolution in various industries, including the automobiles, electronics, and electrical power industries.

scholarly journals THz Reflective Imaging System Utilizing Broadband Homodyne Amplification for Artifact-Free See-Through Imaging

2020 ◽  
Vol 10 (20) ◽  
pp. 7228
Author(s):  
Kiwon Moon ◽  
Il-Min Lee ◽  
Eui Su Lee ◽  
Kyung Hyun Park
Keyword(s):  
Signal Amplification ◽  
Continuous Wave ◽  
Imaging System ◽  
Imaging Techniques ◽  
Thz Imaging ◽  
Material Loss ◽  
Frequency Dependent ◽  
Imaging Capability ◽  
Technical Issues ◽  
Non Destructive

Terahertz (THz) technology offers unique see-through imaging capability for various non-destructive inspection applications. In this work, we implemented a broadband continuous-wave THz imaging system to study technical issues related to the see-through imaging, including frequency-dependent resolution, material loss, and interference-induced artifacts. The interference-induced false contrast and artifacts were observed, which were suppressed by broadband imaging techniques adopting the homodyne signal amplification by interferometric setup to overcome the material loss.

Compact and cost-effective continuous wave THz imaging system

2003 ◽  
Author(s):  
T. Kleine-Ostmann ◽  
P. Knobloch ◽  
M. Koch ◽  
S. Hoffmann ◽  
M. Hofmann ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Imaging System ◽  
Cost Effective ◽  
Thz Imaging

scholarly journals Simulative Investigation of FMCW Based Optical Photonic Radar And Its Different Configurations

2021 ◽  
Author(s):  
Abhishek Sharma ◽  
Jyoteesh Malhotra
Keyword(s):  
Thermal Noise ◽  
Continuous Wave ◽  
Direct Detection ◽  
Smart Cities ◽  
Autonomous Vehicle ◽  
Coherent Detection ◽  
Target Range ◽  
Detection Scheme ◽  
The Cost ◽  
Detection Schemes

Abstract Intelligent transportation is becoming integral part of future smart cities where driverless operations may provide hassle free conveyance. Photonic radar technology is one such contender to deliver attractive applications in autonomous vehicle sector. In this paper we have discussed the basic principle of frequency modulated continuous wave (FMCW) photonic radar and their possible advantages. Further the basic detection schemes that is direct detection and coherent detection is explained mathematically as well as numerical simulations to understand workings is also carried out. The obtained results concludes that direct detection scheme provides minimal complexity in its architecture and is sensitive to received signal strength at the cost of thermal noise and poor sensitivity. On the other hand, coherent detection offers higher target range estimation as well as velocity measurement at the expense of increased system complexity.

A continuous-wave THz imaging system

2013 ◽  
Author(s):  
Ting-Hang Pei ◽  
Yang-Tung Huang ◽  
Yu-Jiu Wang ◽  
Wei-Zen Chen ◽  
Chien-Nan Kuo ◽  
...  
Keyword(s):  
Continuous Wave ◽  
Imaging System ◽  
Thz Imaging

A Pulsed THz Imaging System with a Line Focus and a Balanced 1-D Detection Scheme with Two Industrial CCD Line Cameras

2010 ◽  
Author(s):  
Christian Wiegand ◽  
Michael Herrmann ◽  
Sebastian Bachtler ◽  
Daniel Molter ◽  
Jens Klier ◽  
...  
Keyword(s):  
Imaging System ◽  
Thz Imaging ◽  
Detection Scheme ◽  
Line Focus

scholarly journals A pulsed THz Imaging System with a line focus and a balanced 1-D detection scheme with two industrial CCD line-scan cameras

2010 ◽  
Vol 18 (6) ◽  
pp. 5595 ◽  
Author(s):  
Christian Wiegand ◽  
Michael Herrmann ◽  
Sebastian Bachtler ◽  
Jens Klier ◽  
Daniel Molter ◽  
...  
Keyword(s):  
Imaging System ◽  
Thz Imaging ◽  
Detection Scheme ◽  
Line Scan ◽  
Line Focus

scholarly journals Continuous-Wave THz Imaging for Biomedical Samples

2020 ◽  
Vol 11 (1) ◽  
pp. 71
Author(s):  
Yaya Zhang ◽  
Chuting Wang ◽  
Bingxin Huai ◽  
Shiyu Wang ◽  
Yating Zhang ◽  
...  
Keyword(s):  
Medical Imaging ◽  
Biomedical Imaging ◽  
Continuous Wave ◽  
Biological Tissues ◽  
Thz Spectroscopy ◽  
Label Free ◽  
Thz Imaging ◽  
Malignant Tumours ◽  
Advantages And Disadvantages ◽  
Imaging Application

In the past few decades, the applications of terahertz (THz) spectroscopy and imaging technology have seen significant developments in the fields of biology, medical diagnosis, food safety, and nondestructive testing. Label-free diagnosis of malignant tumours has been obtained and also achieved significant development in THz biomedical imaging. This review mainly presents the research status and prospects of several common continuous-wave (CW) THz medical imaging systems and applications of THz medical imaging in biological tissues. Here, we first introduce the properties of THz waves and how these properties play a role in biomedical imaging. Then, we analyse both the advantages and disadvantages of the CW THz imaging methods and the progress of these methods in THz biomedical imaging in recent ten years. Finally, we summarise the obstacles in the way of the application of THz bio-imaging application technology in clinical detection, which need to be investigated and overcome in the future.

scholarly journals Roadmap of Terahertz Imaging 2021

Sensors ◽  
2021 ◽  
Vol 21 (12) ◽  
pp. 4092
Author(s):  
Gintaras Valušis ◽  
Alvydas Lisauskas ◽  
Hui Yuan ◽  
Wojciech Knap ◽  
Hartmut G. Roskos
Keyword(s):  
Room Temperature ◽  
Continuous Wave ◽  
Computational Imaging ◽  
Imaging Systems ◽  
Thz Imaging ◽  
Operational Conditions ◽  
Frequency Combs ◽  
Wave Imaging ◽  
On Chip ◽  
Nano Imaging

In this roadmap article, we have focused on the most recent advances in terahertz (THz) imaging with particular attention paid to the optimization and miniaturization of the THz imaging systems. Such systems entail enhanced functionality, reduced power consumption, and increased convenience, thus being geared toward the implementation of THz imaging systems in real operational conditions. The article will touch upon the advanced solid-state-based THz imaging systems, including room temperature THz sensors and arrays, as well as their on-chip integration with diffractive THz optical components. We will cover the current-state of compact room temperature THz emission sources, both optolectronic and electrically driven; particular emphasis is attributed to the beam-forming role in THz imaging, THz holography and spatial filtering, THz nano-imaging, and computational imaging. A number of advanced THz techniques, such as light-field THz imaging, homodyne spectroscopy, and phase sensitive spectrometry, THz modulated continuous wave imaging, room temperature THz frequency combs, and passive THz imaging, as well as the use of artificial intelligence in THz data processing and optics development, will be reviewed. This roadmap presents a structured snapshot of current advances in THz imaging as of 2021 and provides an opinion on contemporary scientific and technological challenges in this field, as well as extrapolations of possible further evolution in THz imaging.

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