动态可调的太赫兹超构表面

近年来，采用人工设计金属阵列的超构表面以实现对太赫兹波的调制受到越来越广泛的关注。设计了2种互补的亚波长金结构阵列超构表面，正、反结构2个超构表面对太赫兹波均有共振响应。利用光泵浦太赫兹时域透射光谱系统，通过控制泵浦光实现对太赫兹波的谱调制。仅需28 mW的外加泵浦光，反结构超构表面在0.91 THz处的振幅调制深度可达到95%。利用该反结构超构表面对太赫兹波的开关作用，进一步设计了太赫兹振幅全息图，希望利用该结构实现太赫兹波前的动态调控。初步的理论模拟验证了这一方法的可行性，可较好地实现对太赫兹波的动态调控。

Dynamically tunable terahertz metasurface

In recent years, the use of artificially designed metasurface of metallic arrays to achieve modulation of terahertz wave has received increasing attention. Two complementary metasurfaces of gold subwavelength structure array are proposed. Both of two metasurfaces, positive and negative structures, have resonance responses to terahertz wave. The optical control terahertz time-domain spectrum system is utilized to measure the spectral modulation of the terahertz wave by controlling the pump light. With pump light of 28 mW, the negative structure metasurface can have an amplitude modulation depth up to 95% at 0.91 THz. The amplitude holography is further designed by using this negative structure metasurface to modulate the terahertz wavefront. The simulation result demonstrates the feasibility of the proposed method. This approach can achieve dynamic modulation of terahertz wave, which is of great significance to the development of terahertz dynamic adjustable function devices.