title: Frequency-agile electromagnetically induced transparency analogue in terahertz metamaterials.
abstract: Recently reported active metamaterial analogues of electromagnetically induced transparency (EIT) are promising in developing novel optical components, such as active slow light devices. However, most of the previous works have focused on manipulating the EIT resonance strength at a fixed characteristic frequency and, therefore, realized on-to-off switching responses. To further extend the functionalities of the EIT effect, here we present a frequency tunable EIT analogue in the terahertz regime by integrating photoactive silicon into the metamaterial unit cell. A tuning range from 0.82 to 0.74 THz for the EIT resonance frequency is experimentally observed by optical pump-terahertz probe measurements, allowing a frequency tunable group delay of the terahertz pulses. This straightforward approach delivers frequency agility of the EIT resonance and may enable novel ultrafast tunable devices for integrated plasmonic circuits.
authors.forename: Quan
authors.initials: Q
authors.lastname: Xu
authors.forename: Xiaoqiang
authors.initials: X
authors.lastname: Su
authors.forename: Chunmei
authors.initials: C
authors.lastname: Ouyang
authors.forename: Ningning
authors.initials: N
authors.lastname: Xu
authors.forename: Wei
authors.initials: W
authors.lastname: Cao
authors.forename: Yuping
authors.initials: Y
authors.lastname: Zhang
authors.forename: Quan
authors.initials: Q
authors.lastname: Li
authors.forename: Cong
authors.initials: C
authors.lastname: Hu
authors.forename: Jianqiang
authors.initials: J
authors.lastname: Gu
authors.forename: Zhen
authors.initials: Z
authors.lastname: Tian
authors.forename: Abul K
authors.initials: AK
authors.lastname: Azad
authors.forename: Jiaguang
authors.initials: J
authors.lastname: Han
authors.forename: Weili
authors.initials: W
authors.lastname: Zhang