We present a terahertz (THz) amplitude modulation method with near perfect E-field amplitude modulation depths that is based on impedance matching in VO₂ thin films during the thermally induced insulator-metal transition (IMT). It was observed that the impedance matching-induced THz amplitude modulation was sensitive to the resistance switching characteristics of the VO₂ thin films. By designing the VO₂ thin films to have four orders of magnitude of change in resistance during the IMT, we experimentally achieved an E-field amplitude modulation depth of 94.5% (intensity modulation depth of 99.7%) between the insulator phase of VO₂ and the impedance matching state, and an E-field amplitude modulation depth of 97.6% (intensity modulation depth of 99.94%) between the impedance matching state and the metallic phase of VO₂ at 0.5 THz. The experimental results were consistent with the results of simulations based on the transmission matrix model.

中文翻译：

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通过VO2薄膜中的阻抗匹配实现接近完美的太赫兹波幅度调制

我们提出了一种太赫兹（THz）振幅调制方法，具有接近完美的电场振幅调制深度，该方法基于热感应绝缘体-金属转变（IMT）期间VO ₂薄膜中的阻抗匹配。观察到，阻抗匹配引起的太赫兹幅度调制对VO ₂薄膜的电阻切换特性敏感。通过将VO ₂薄膜设计为在IMT期间电阻具有四个数量级的变化，我们通过实验获得了VO ₂绝缘体相之间的电场幅度调制深度为94.5％（强度调制深度为99.7％）。阻抗匹配状态和阻抗匹配状态与0.5 THz的VO ₂的金属相之间的电场幅度调制深度为97.6％（强度调制深度为99.94％）。实验结果与基于传输矩阵模型的仿真结果一致。