Abstract-High-resolution reconstruction for terahertz imaging.

Authors : Xu Li-Min, Fan Wen-Hui, Liu Jia,

http://antibody-antibodies.com/pubmed-25607865-Highresolution_reconstruction_for_terahertz_imaging.html

We present a high-resolution (HR) reconstruction model and algorithms for terahertz imaging, taking advantage of super-resolution methodology and algorithms. The algorithms used include projection onto a convex sets approach, iterative backprojection approach, Lucy-Richardson iteration, and 2D wavelet decomposition reconstruction. Using the first two HR reconstruction methods, we successfully obtain HR terahertz images with improved definition and lower noise from four low-resolution (LR) 22×24 terahertz images taken from our homemade THz-TDS system at the same experimental conditions with 1.0 mm pixel. Using the last two HR reconstruction methods, we transform one relatively LR terahertz image to a HR terahertz image with decreased noise. This indicates potential application of HR reconstruction methods in terahertz imaging with pulsed and continuous wave terahertz sources.

Abstract-Multiband terahertz metamaterial absorber

Gu Chao (顾 超)¹, Qu Shao-Bo (屈绍波)^1,2, Pei Zhi-Bin (裴志斌)¹, Xu Zhuo (徐 卓)², Liu Jia (刘 嘉)¹ and Gu Wei (顾 巍)³

15929560875@139.com

¹ The College of Science, Air Force University of Engineering, Xi'an 710051, China 

² Electronic Materials Research Laboratory, Key Laboratory of Ministry of Education, Xi'an Jiaotong University, Xi'an 710049, China 

³ The Engineering and Technical College of Chengdu University of Technology Department of Computer Science and Technology, Leshan 614300, China 

http://iopscience.iop.org/1674-1056/20/1/017801?rel=sem&relno=5

This paper reports the design of a multiband metamaterial (MM) absorber in the terahertz region. Theoretical and simulated results show that the absorber has four distinct and strong absorption points at 1.69, 2.76, 3.41 and 5.06 THz, which are consistent with 'fingerprints' of some explosive materials. The retrieved material parameters show that the impedance of MM could be tuned to match approximately the impedance of the free space to minimise the reflectance at absorption frequencies and large power loss exists at absorption frequencies. The distribution of the power loss indicates that the absorber is an excellent electromagnetic wave collector: the wave is first trapped and reinforced in certain specific locations and then consumed. This multiband absorber has applications in the detection of explosives and materials characterisation.