We propose a tunable terahertz (THz) metamaterial absorber with a grating structure based on the phase transition characteristic of vanadium dioxide (VO). We use deep learning method to assist the design of THz metamaterial absorber and use finite-difference time domain (FDTD) method to simulate its absorptance. The results show that the phase transition of VO will cause the absorber to exhibit completely different absorption properties in the frequency range of 30 THz to 70 THz when the structural parameters and materials of the absorber are fixed, namely the metal-insulator transition of VO leads to the transition of absorption properties of the absorber from ultra-broadband absorption to single absorption peak, and vice versa. Therefore, the absorptance of the metamaterial absorber can be adjusted by changing the conductivity of VO, making the proposed THz metamaterial absorber has great potential applications in THz broadband absorber, temperature controlled tunable absorber and THz switch.

中文翻译：

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基于深度学习方法的可调谐太赫兹超材料吸收体优化

我们提出了一种基于二氧化钒（VO）相变特性的具有光栅结构的可调谐太赫兹（THz）超材料吸收器。我们利用深度学习方法辅助太赫兹超材料吸收体的设计，并利用时域有限差分（FDTD）方法来模拟其吸收率。结果表明，当吸收体的结构参数和材料一定时，VO的相变会导致吸收体在30 THz~70 THz频率范围内表现出完全不同的吸收特性，即VO引线的金属-绝缘体转变吸收体的吸收特性从超宽带吸收转变为单吸收峰，反之亦然。因此，可以通过改变VO的电导率来调节超材料吸收器的吸收率，使得所提出的太赫兹超材料吸收器在太赫兹宽带吸收器、温控可调谐吸收器和太赫兹开关中具有巨大的潜在应用。