Lu Ja-Yu, Chen Hao-Zai, Lai Chih-Hsien, Chang Hung-Chun, You Borwen, Liu Tze-An, Peng Jin-Long
Institute of Electro-Optical Science and Engineering and Advanced Optoelectronic Technology Center, National Cheng Kung University, Tainan, Taiwan.
Opt Express. 2011 Jan 3;19(1):162-7. doi: 10.1364/OE.19.000162.
A novel tunable terahertz notch filter is demonstrated using antiresonant reflecting hollow waveguides with movable metal layers outside dielectric claddings. Based on the Fabry-Pérot resonance of the dielectric cladding, multiple deep notches are observed in a broad THz transmission spectrum. Continuous shift of notch frequencies is for the first time experimentally observed by lateral translation of metal layers from dielectric claddings. The measured maximum frequency-tuning-range approached 60GHz, equaling to 50% of the bandwidth of every passband, and a 20dB rejection notch-depth with a linewidth as narrow as 6GHz at frequency of around 0.2THz was also achieved. Numerical simulations match the measurements and verify the spectral-tuning mechanism.
利用介质包层外部带有可移动金属层的反谐振反射空心波导，展示了一种新型可调谐太赫兹陷波滤波器。基于介质包层的法布里-珀罗共振，在宽太赫兹传输光谱中观察到多个深陷波。通过将金属层从介质包层横向平移，首次在实验中观察到陷波频率的连续移动。测量的最大频率调谐范围接近60GHz，相当于每个通带带宽的50%，并且在约0.2THz频率处还实现了20dB抑制陷波深度，线宽窄至6GHz。数值模拟与测量结果相符，并验证了光谱调谐机制。
