Lee Eui Su, Jeon Tae-In
Division of Electrical and Electronics Engineering, Korea Maritime University, Busan 606-791, South Korea.
Opt Express. 2012 Dec 31;20(28):29605-12. doi: 10.1364/OE.20.029605.
A single groove in a parallel-plate waveguide (PPWG) has been applied to a tunable terahertz (THz) notch filter with a transverse-electromagnetic (TEM) mode. When the air gap between the metal plates of the PPWG is controlled from 60 to 240 μm using a motor controlled translation stage or a piezo-actuator, the resonant frequency of the notch filter is changed from 1.75 up to 0.62 THz, respectively. Therefore, the measured tunable sensitivity of the notch filter increases to 6.28 GHz/μm. The measured resonant frequencies were found to be in good agreement with the calculation using an effective groove depth. Using a finite-difference time-domain (FDTD) simulation, we also demonstrate that the sensitivity of a THz microfluidic sensor can be increased via a small air gap, a narrow groove width, and a deep groove depth.
平行板波导（PPWG）中的单个凹槽已应用于具有横向电磁（TEM）模式的可调太赫兹（THz）陷波滤波器。当使用电机控制的平移台或压电致动器将PPWG金属板之间的气隙从60μm控制到240μm时，陷波滤波器的谐振频率分别从1.75 THz变化到0.62 THz。因此，测得的陷波滤波器可调灵敏度提高到6.28 GHz/μm。发现测得的谐振频率与使用有效凹槽深度的计算结果吻合良好。使用时域有限差分（FDTD）模拟，我们还证明了太赫兹微流体传感器的灵敏度可以通过小的气隙、窄的凹槽宽度和深的凹槽深度来提高。
