Ji Jie, Zhou Siyan, Wang Weijun, Luo Chunya, Liu Yong, Ling Furi, Yao Jianquan
Opt Express. 2019 Feb 4;27(3):2363-2373. doi: 10.1364/OE.27.002363.
An active multifunctional terahertz modulator based on plasmon-induced transparency (PIT) metasurface under the effect of external infrared light was investigated theoretically and experimentally. A distinct transparency window, which resulted from the near-field coupling between two resonators, could be observed in the transmission spectra. Experimental results showed a phenomenon infrared light induced blue shift on the both resonator with increasing optical powers. When the optical power was tuned from 0 mW to 400 mW, the amplitude tunability of transmission at transparency window reached to 34.01%, much larger than that at the two resonance frequencies. Moreover, the phase tunability of the transmission at 0.98 THz reached to 31.35%. Meanwhile, the amplitude variation was limited to 10%. Furthermore, a coupled Lorentz oscillator model was adopted to analyze the near-field interaction of the resonances. Experimental results were in good agreement with the analytical fitting results.
理论和实验研究了一种基于表面等离激元诱导透明（PIT）超表面的有源多功能太赫兹调制器，该调制器在外加红外光作用下工作。在透射光谱中可观察到由两个谐振器之间的近场耦合产生的明显透明窗口。实验结果表明，随着光功率增加，红外光会使两个谐振器都发生蓝移现象。当光功率从0 mW调至400 mW时，透明窗口处透射率的幅度可调性达到34.01%，远大于两个谐振频率处的可调性。此外，0.98 THz处透射率的相位可调性达到31.35%。同时，幅度变化限制在10%以内。此外，采用耦合洛伦兹振子模型分析谐振的近场相互作用。实验结果与分析拟合结果吻合良好。
