High-sensitivity modulation of electromagnetically induced transparency analog in a THz asymmetric metasurface integrating perovskite and graphene
Tongling Wang, Tengteng Li, Haiyun Yao, Yu‐Ying Lu, Xin Yan, Maoyong Cao, Lanju Liang, Maosheng Yang, Jianquan Yao
Abstract
Active control of the electromagnetically induced transparency (EIT) analog is desirable in photonics development. Here, we theoretically and experimentally proposed a novel terahertz (THz) asymmetric metasurface structure that can possess high-sensitivity modulation under extremely low power density by integrating perovskite or graphene. Using the novel metasurface structure with the perovskite coating, the maximum amplitude modulation depth (AMD) of this perovskite-based device reached 490.53% at a low power density of <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m1"> <mml:mrow> <mml:mn>12.8037</mml:mn> <mml:mtext> </mml:mtext> <mml:msup> <mml:mrow> <mml:mi>mW</mml:mi> <mml:mo>/</mml:mo> <mml:mi>cm</mml:mi> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> </mml:mrow> </mml:math> . In addition, after the novel THz metasurface structure was combined with graphene, this graphene-based device also achieved high AMD with the maximum AMD being 180.56% at <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" id="m2"> <mml:mrow> <mml:mn>16.312</mml:mn> <mml:mtext> </mml:mtext> <mml:msup> <mml:mrow> <mml:mi>mW</mml:mi> <mml:mo>/</mml:mo> <mml:mi>cm</mml:mi> </mml:mrow> <mml:mn>2</mml:mn> </mml:msup> </mml:mrow> </mml:math> , and its transmission amplitude could be electrically driven at a low bias voltage. The physical origin of this modulation was explained using a two-oscillator EIT model. This work provides a promising platform for developing high-sensitivity THz sensors, light modulators, and switches.