Active control optical terahertz modulator based on incorporating n-type GaAs film as the active media into plasmon-induced transparency metasurface, was investigated theoretically and experimentally. From the experimental results it could be found that the resonances transmission of the plasmon-induced transparency was optically modulated and the transmission modulation depth of 87% was achieved at 0.56 THz. This may be due to the fact that when the pump excitation power was tuned from 0 mW to 1000 mW, larger numbers of excited carriers were excited in the electronic “p-n" junction and diffused across the heterojunction to the n-type GaAs film. It increased the conductivity of the n-type GaAs film from 2.29 × 10³ S/m to 1.56 × 10⁴ S/m. As a results, the capacitive split gaps of the PIT split-ring resonators were short-circuited and the coupling strength between the resonators was decreased owing to the screening effect caused by the photo-excited carriers.

从理论上和实验上研究了基于将 n 型 GaAs 薄膜作为活性介质纳入等离子体诱导的透明超表面的主动控制光学太赫兹调制器。从实验结果可以发现，等离子体诱导透明的共振传输是光学调制的，并且在 0.56 THz 下实现了 87% 的传输调制深度。这可能是因为当泵浦激发功率从 0 mW 调整到 1000 mW 时，更多数量的激发载流子在电子“pn”结中被激发并通过异质结扩散到 n 型 GaAs 薄膜。将 n 型 GaAs 薄膜的电导率从 2.29 × 10 ³  S/m 提高到 1.56 × 10 ⁴ 秒/米。结果，由于光激发载流子引起的屏蔽效应，PIT裂环谐振器的电容分裂间隙短路，谐振器之间的耦合强度降低。