TST, Vol. 8, No. 4, PP. 129-144
(Invited paper) Doped silicon-based broadband terahertz absorber: a review
XiaoFei Zang, YiMing Zhu *, and Songlin Zhuang
Shanghai Key Lab of Modern Optical System, Engineering Research Center of Optical Instrument and System, Ministry of Education, University of Shanghai for Science and Technology, 516, Jungong Rd. Yangpu Dist. Shanghai, China, 200093
* Email: ymzhu@usst.edu.cn
(Received August 18, 2015 )
Abstract: Wideband absorption with high efficiency has attracted much attention due to the potential applications in imaging, anti-radar cloaking devices, sensors, detectors, and so on. Recently, meta-based periodical resonance structure (metamaterials) is proposed to realize perfect absorber. However, it suffers from the absorption of terahertz (THz) waves just in the single-frequency or narrow band width owing to its resonance features. Here, in this review, we discuss various THz broadband absorbers by fabricating gratings on heavily boron-doped silicon substrate. By optimizing the grating structure, the absorption bandwidths are 1 THz, 1.5 THz, and 2.0 THz, respectively with absorbance above 95%.
Keywords: Terahertz absorber, First-order diffraction, Second-order diffraction, Air-gap mode.
doi: 10.11906/TST.129-144.2015.12.13
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TST, Vol. 8, No. 4, PP. 145-156
(Invited paper) Terahertz isolator based on magneto-microstructure
Sai. Chen, Fei. Fan, and Sheng-Jiang. Chang *
Institute of Modern Optics, Nankai University, Tianjin 300071, China
* Email: sjchang@nankai.edu.cn
(Received August 18, 2015 )
Abstract: In this paper, we have reviewed our study in terahertz (THz) isolators and nonreciprocal transmission devices, with an emphasis on novel isolators based on a new kind of physical mechanism. In combination with microstructure and magneto-opitical material, we have presented different forms of THz isolators, such as plasmonic waveguides, plasmonic lens, photonic crystal cavity and magneto-metasurface. Moreover, we have discussed and concluded the necessary conditions of forming THz nonreciprocal transmission in the magneto-microstructure devices, which is strongly related with magneto-material and asymmetric transmission system. THz isolators are important for the realization high efficient THz systems.
Keywords: Terahertz spectroscopy, Isolators.
doi: 10.11906/TST.145-156.2015.12.14
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TST, Vol. 8, No. 4, PP. 157-169
(Invited paper) The gyrotron: physical genealogy
M. I. Petelin *
Institute of Applied Physics, Nizhny Novgorod, Russia
* Email: petelin@appl.sci-nnov.ru
(Received March 12, 2015)
Abstract: This paper is a modification of a review talk delivered by the author at the THz Symposium-2015, Soochow. Elementary fundamentals of the gyrotron – a version of classical electron masers - are summarized.
Keywords: Gyrotron, Cyclotron resonance masers, Mode selection, Quasi-Gaussian beam
doi: 10.11906/TST.157-169.2015.12.15
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TST, Vol. 8, No. 4, PP. 170-178
Parallel electron beam excitation of surface plasmon polaritons in double layer graphene sheets
Gongs Sen, Hu Min, Zhong Renbing, Chen Xiaoxing, Zhang Ping, Zhao Tao, and Liu Shenggang *
Cooperative Innovation Centre of THz Science, University of Electronic Science and Technology of China,Chengdu,610054, China
* Email: liusg@uestc.edu.cn
(Received November 30, 2015)
Abstract: In this paper, we present the parallel electron beam excitation of the surface plasmon polaritons (SPPs) in the double layer graphene sheets. The results of the theoretical analysis and numerical calculations show that the excited SPPs in the double layer graphene sheets have many characteristics and advantages compared to that in single layer graphene sheet. For the double layer graphene sheets, SPPs are spilt into two modes due to the coupling of SPPs, and the mode with higher frequency can be excited by parallel electron beam efficiently. The excited SPPs have higher operating frequencies and stronger field amplitudes than that in single layer graphene sheet, and the operating frequency can also be tuned by electron beam energy and chemical potential.
Keywords: Electron beam, Double layer graphene sheets, Surface plasmon polaritons.
doi: 10.11906/TST.170-178.2015.12.16
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