通过将三元体系单斜相结构弛豫铁电单晶铌铟镁酸铅–钛酸铅[Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–Pb Ti O3(PIN–PMN–PT)]的准同型相界组分0.24PIN–0.43PMN–0.33PT单晶沿[011]c方向极化成准单畴态,研究了该单晶的电光性能。采用改进...通过将三元体系单斜相结构弛豫铁电单晶铌铟镁酸铅–钛酸铅[Pb(In1/2Nb1/2)O3–Pb(Mg1/3Nb2/3)O3–Pb Ti O3(PIN–PMN–PT)]的准同型相界组分0.24PIN–0.43PMN–0.33PT单晶沿[011]c方向极化成准单畴态,研究了该单晶的电光性能。采用改进的Mach-Zehnder干涉系统,选用波长为632.8nm激光对单晶的电光系数张量?13、?23和?33进行测量及分析。根据实验及计算结果,排除由压电效应引起晶体在通光方向的伸缩,电光系数张量?13=–21.8 pm/V,?23=64.7 pm/V,?33=85.8 pm/V。测试结果表明,单晶的电光系数具有较高的?23和?33分量,在实际的电光器件应用中,可以在保证单晶透过率的情况下对这两个分量进行利用。展开更多
This paper investigates the electromagnetic radiation characteristics of a metallic, large aspect ratio single walled carbon nanotube antenna in the terahertz frequency region below 12.5 THz. The key features of terah...This paper investigates the electromagnetic radiation characteristics of a metallic, large aspect ratio single walled carbon nanotube antenna in the terahertz frequency region below 12.5 THz. The key features of terahertz pulse have been revealed on the carbon nanotube antenna in comparison with conventional photoconductive switching. The terahertz waveforms, radiation power and their field distributions have been evaluated and are analysed. The Fourier transformed spectra over the whole frequency range demonstrate that the carbon nanotube antenna can be used as radiation source for broadband terahertz applications.展开更多
In this paper, we present the design, simulation, fabrication and characterization of a terahertz(THz) filter based on metamaterial consisting of the periodical double symmetric splits ring resonator(DS-SRR) array. We...In this paper, we present the design, simulation, fabrication and characterization of a terahertz(THz) filter based on metamaterial consisting of the periodical double symmetric splits ring resonator(DS-SRR) array. We can observe that the metamaterial-based filter possesses a band-pass transmission when the electrical field is along y direction, and it possesses a low-pass transmission when the electrical field is along x direction. Our results demonstrate that the proposed filter can realize the switching between band-pass effect and low-pass effect by only changing the polarization direction of the incident electromagnetic wave. Moreover, the calculated surface current distributions are also used to analyze the switchable mechanism of the THz metamatrial filter. Therefore, the proposed THz wave filter has a potential application in THz wave communication systems.展开更多
基金supported by the National Natural Science Foundation of China(Grant No 60571026)the Science and Technology Research Foundation of Heilongjiang Education Bureau of China(Grant No 11531055)
文摘This paper investigates the electromagnetic radiation characteristics of a metallic, large aspect ratio single walled carbon nanotube antenna in the terahertz frequency region below 12.5 THz. The key features of terahertz pulse have been revealed on the carbon nanotube antenna in comparison with conventional photoconductive switching. The terahertz waveforms, radiation power and their field distributions have been evaluated and are analysed. The Fourier transformed spectra over the whole frequency range demonstrate that the carbon nanotube antenna can be used as radiation source for broadband terahertz applications.
基金supported by the Major State Basic Research Development Program of China(No.2010CB934104)the Science and Technology Research Funding of State Cultural Relics Bureau Cultural Relics(No.20110135)+1 种基金the National Special Fund for the Development of Major Research Equipment and Instruments(No.2012YQ14000508)"985 Project"(No.0301-01402904)
文摘In this paper, we present the design, simulation, fabrication and characterization of a terahertz(THz) filter based on metamaterial consisting of the periodical double symmetric splits ring resonator(DS-SRR) array. We can observe that the metamaterial-based filter possesses a band-pass transmission when the electrical field is along y direction, and it possesses a low-pass transmission when the electrical field is along x direction. Our results demonstrate that the proposed filter can realize the switching between band-pass effect and low-pass effect by only changing the polarization direction of the incident electromagnetic wave. Moreover, the calculated surface current distributions are also used to analyze the switchable mechanism of the THz metamatrial filter. Therefore, the proposed THz wave filter has a potential application in THz wave communication systems.
