Preface
The editorial office would extend great appreciation to Prof. Wei Shi for his great support to this issue.
As an invited guest editor of TST, he has brought readers two interesting invited papers: one is on the measurement of Terahertz radiation characteristics from blackbody with bolometer radiometer, model on how to measure the terahertz radiation of low-temperature and normal-temperature is established and applied on the testing of folded waveguide traveling-wave tube; Another one is on the calculation method study for THz pulse generation, to realize high conversion efficiency by optical rectification of ultrashort laser pulses with tilted pulse fronts, which is a novel and attractive research work.
Hope this issue will bring readers some different respects on THz research work.
Editorial Office of TST
Jun 30, 2017
TST, Vol. 10, No. 2, PP. 44-53
(Invited paper) Study on radiation parameter measurement of terahertz source based on bolometer radiometer
Li Hongguang 1* , Yu Bing 1, Zhao Xinzhan 2 , Xie Qi 1 , Yang Hongru 1，Ma Shibang 1, and Wang Xing 1
1 Xi'an Institute of Applied Optics, Xi'an, 710065, China
2 China Research and Development Academy of Machinery Equipment, Beijing, 100089, China
* Email: optics_lihg@126.com
(Received June 1, 2017)
Abstract: Terahertz radiation characteristics of blackbody are theoretic basic of detecting terahertz radiation, and also the key of how to calibrate and measure terahertz sources. Terahertz radiation characteristics of blackbody are analyzed, and terahertz bolometer radiometer is built, then the terahertz radiance of blackbody, which temperature range is (223～323) K, are tested by bolometer radiometer. Furthermore, the radiance of folded waveguide traveling-wave tube is tested. The results show that the method which can test terahertz radiation parameter of terahertz source is provided.
Key words: Terahertz source measurement, Radiation blackbody, Terahertz bolometer radiometer
doi: 10.11906/TST.044-053.2017.06.02
View Full Text: PDF
TST, Vol. 10, No. 2, PP. 54-61
(Invited paper) The calculation method of high conversion efficiency THz pulse generation by optical rectification of ultrashort laser pulses with tilted pulse fronts
Lei Yang , Wei Shi * , Lei Hou , Chengang Dong , and Panpan Wang
Applied Physics Department, Xi’an University of Technology, Xi’an, China, 710048
* Email: swshi@mail.xaut.edu.cn
(Received June 1, 2017)
Abstract: The high conversion generation efficiency THz generation through optical rectification using a tilted optical pulse front is described. A calculation method of tilted-pulse-front scheme has detailed descriptions, including the tilt introduced by the grating, increase of the pulse front tilt by demagnification in the imaging of the pulse from the grating onto the generation crystal, and propagation of the tilted intensity front from free-space into the generation crystal. We get an optimal demagnification 3.75 of the imaging system for maximum THz conversion efficiency (□0.1519×10-3).
Keywords: Terahertz , Lithium niobate (LiNbO3 ), Optical rectification, Tilted pulse fronts
doi: 10.11906/TST.054-061.2017.06.03
View Full Text: PDF
TST, Vol. 10, No. 2, PP. 62-70
Modeling, simulation and implementation of imaging system for detection of hidden objects
Triveni Keskar 1, 2*, Vijay R. Dahake 1, and Anuj Bhatnagar 2
1 Department of Electronics and Telecommunication, Ramrao Adik Institute of Technology, Navi Mumbai, India
2 Society for Applied Microwave Electronics Engineering and Research, IIT Bombay, Powai, India
* Email: trivenikeskar@gmail.com
(Received April 10, 2017)
Abstract: The proliferation of applicability of extremely high frequency band close to Terahertz frequencies for its signature characteristics such as reflection from metals, low loss transmission from non-polar dielectrics and specific absorption for wide range of liquids and drugs has been the interest behind this paper. We have modeled the system at 110 GHz to obtain simulation results justifying the system design. We have presented a practical implementation with 89.4 GHz IMPATT diode source for a small area TeraSense camera detector (4.5cm×4.5cm) and an XY direction moving stage controlled by Holmarc MicroMotion platform for capturing raster scan imaging of large objects based on the results. We also have tried to make the result more intuitive to the user using edge detection and intensity analysis in image processing domain. We are able to detect non-invasively, an object within 34cm×22cm area, in 4 minutes, which has been hidden under or inside a 4 mm thick cardboard or clothing covering.
Keywords: TracePro, MATLAB image processing, Symbolic math and GUI toolbox, Holmarc Micro Motion, TeraSense IMPATT diode.
doi: 10.11906/TST.062-070.2017.06.04
View Full Text: PDF
