Practical dual-band terahertz imaging system.

This paper introduces a dual-band terahertz imaging system as a potential product for nondestructive testing using heterodyne detectors and continuous-wave sources. The operating frequencies of the system are 110.4 and 220.8 GHz. Multiband fusion technology combines the advantages of the greater spatial resolution of the high-frequency band and the enhanced sensitivity of the low-frequency band to improve the detection ability of the system. Additionally, the interference cancellation technology is used to obtain a superior image quality. The spatial resolution of this system was approximately 3 mm. The results show that the system can be used for bonding quality and embedded defect detection in radomes and foam materials adhered to metal plates in aircrafts.

[1]  K. Yngvesson,et al.  Wideband IF-Integrated Terahertz HEB Mixers: Modeling and Characterization , 2010, IEEE Transactions on Microwave Theory and Techniques.

[2]  J. Federici,et al.  THz imaging and sensing for security applications—explosives, weapons and drugs , 2005 .

[3]  Yulei Shi,et al.  Collective vibrational spectra of α- and γ-glycine studied by terahertz and Raman spectroscopy , 2005, Photoelectronic Detection and Imaging.

[4]  Izaak V. Kemp,et al.  Nondestructive terahertz imaging for aerospace applications , 2009, Security + Defence.

[5]  E. Madaras,et al.  Nondestructive defect identification with terahertz time-of-flight tomography , 2005, IEEE Sensors Journal.

[6]  N. Karpowicz,et al.  Sensing and Imaging with Continuous‐Wave Terahertz Systems , 2006 .

[7]  Chun Yang,et al.  Recent Developments of an Opto-Electronic THz Spectrometer for High-Resolution Spectroscopy , 2009, Sensors.

[8]  Derek Abbott,et al.  Biosensing with T-ray spectroscopy , 2007, European Conference on Biomedical Optics.

[9]  J Grajal,et al.  Physics-Based Design and Optimization of Schottky Diode Frequency Multipliers for Terahertz Applications , 2010, IEEE Transactions on Microwave Theory and Techniques.

[10]  S. D. Vogel.  Design and measurements of a novel subharmonically pumped millimeter-wave mixer using two single planar Schottky-barrier diodes , 1996 .

[11]  R. Weikle,et al.  A 5 mW and 5% efficiency 210 GHz InP-based heterostructure barrier varactor quintupler , 2004, IEEE Microwave and Wireless Components Letters.