Terahertz evanescent field microscopy of dielectric materials using on-chip waveguides
Terahertz evanescent field microscopy of dielectric materials using on-chip waveguides
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使用片上波导对介电材料进行太赫兹倏逝场显微镜观察
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
A. Davies
中科院分区：
文献类型：
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作者：
J. Cunningham;M. Byrne;P. Upadhya;M. Lachab;E. Linfield;A. Davies
我们展示了一个倏逝场模态太赫兹频率时域测量，基于样品和倏逝场之间的相互作用，上面光刻定义的太赫兹波导延伸。我们量化这种相互作用，使用可自由定位的电介质样品（GaAs）移动到波导（太赫兹微带线）附近，发现微带传播脉冲幅度的减少和其时间延迟的增加时，电介质被带入微带倏逝场。我们还表明，谐振无源电路元件（短截线带阻滤波器），集成到微带线的频率响应，可用于确定太赫兹频率特性的扫描样品，开辟了太赫兹亚波长成像模式，其分辨率是有限的光刻约束，而不是由自由空间衍射的方式。
We demonstrate an evanescent field modality for terahertz frequency time-domain measurements, based on the interaction between a sample and the evanescent field extending above lithographically defined terahertz waveguides. We quantify this interaction using freely positionable dielectric samples (GaAs) moved in close proximity to the waveguide (a terahertz microstrip line), finding a reduction in the microstrip-propagating pulse amplitude and an increase in its time delay when the dielectric is brought into the microstrip evanescent field. We also show that the frequency response of resonant passive circuit elements (stub band-stop filters), integrated into the microstrip line, can be used to determine the terahertz frequency properties of scanned samples, opening the way for a terahertz subwavelength imaging modality, the resolution of which is limited by lithographic constraints, rather than by free-space diffraction.