Strong-field terahertz control of plasmon induced opacity in photoexcited metamaterial
Strong-field terahertz control of plasmon induced opacity in photoexcited metamaterial
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DOI：
10.1364/josab.409224
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发表时间：
2020-09
期刊：
影响因子：
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通讯作者：
A. Mousavian;Z. J. Thompson;Byounghwak Lee;Alden N. Bradley;Milo Sprague;Yun-Shik Lee
中科院分区：
文献类型：
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作者：
A. Mousavian;Z. J. Thompson;Byounghwak Lee;Alden N. Bradley;Milo Sprague;Yun-Shik Lee
由辐射缝隙天线和次辐射互补开口环谐振器组成的太赫兹超材料由于耦合振荡器的亮模和暗模之间的相消干涉而在窄光谱范围内表现出等离子体激元诱导的不透明性。飞秒光激发瞬间淬灭模式耦合和等离子体激元振荡，将光载流子注入超材料中。耦合超材料中的等离子体共振被强太赫兹脉冲瞬时恢复。强太赫兹场诱导光生载流子的谷间散射和带间隧穿，从而显着降低光生载流子的迁移率。非线性太赫兹相互作用的超快动力学揭示了光生载流子和等离子体激元振荡之间复杂的相互作用。等离子体激元振荡的高场THz控制意味着超高速等离子体激元的潜在应用。
A terahertz metamaterial consisting of radiative slot antennas and subradiant complementary split-ring resonators exhibits plasmon induced opacity in a narrow spectral range due to the destructive interference between the bright and dark modes of the coupled oscillators. Femtosecond optical excitations instantly quench the mode coupling and plasmon oscillations, injecting photocarriers into the metamaterial. The plasmon resonances in the coupled metamaterial are transiently restored by intense terahertz pulses. The strong terahertz fields induce intervalley scattering and interband tunneling of the photocarries, and achieve significant reduction of the photocarrier mobility. The ultrafast dynamics of the nonlinear THz interactions reveals intricate interplay between photocarriers and plasmon oscillations. The high-field THz control of the plasmon oscillations implies potential applications to ultrahigh-speed plasmonics.