Actively tunable THz filter based on an electromagnetically induced transparency analog hybridized with a MEMS metamaterial

Abstract

Electromagnetically induced transparency (EIT) analogs in classical oscillator systems have been investigated due to their potential in optical applications such as nonlinear devices and the slow-light field. Metamaterials are good candidates that utilize EIT-like effects to regulate optical light. Here, an actively reconfigurable EIT metamaterial for controlling THz waves, which consists of a movable bar and a fixed wire pair, is numerically and experimentally proposed. By changing the distance between the bar and wire pair through microelectromechanical system (MEMS) technology, the metamaterial can controllably regulate the EIT behavior to manipulate the waves around 1.832 THz, serving as a dynamic filter. A high transmittance modulation rate of 38.8% is obtained by applying a drive voltage to the MEMS actuator. The dispersion properties and polarization of the metamaterial are also investigated. Since this filter is readily miniaturized and integrated by taking advantage of MEMS, it is expected to significantly promote the development of THz-related practical applications such as THz biological detection and THz communications.

Actively MEMS-Based Tunable Metamaterials for Advanced and Emerging Applications

“…By applying voltage on the comb driver, a continuous lateral shifting between the coupled resonators can be induced to 20 µm. A MEMS integrated device is proposed by using EIT metamaterial, as shown in Figure 5e [84]. The comb driver design is composed of a fixed beam and a movable beam based on a silicon on insulator (SOI) wafer.…”

“…The geometry of integrated metamaterial is rapidly reduced, which means the MEMS-based metamaterial can be gradually operated from THz and IR, as well as visible spectra [90]. [80]; (b) schematic of the switchable magnetic metamaterial consisting of two semi-square split rings separated by a gap [81]; (c) schematics of the micromachined metamaterial with the element consisting of a two-cut SRR and two free-hanging slabs [82]; (d) schematic of the tunable metamaterials, including broadside-coupled SRRs (BC-SRRs) [83]; (e) schematic of the MEMS integrated device-unit cell of the EIT metamaterial consists of a cut wire and a wire pair [84]; (f) schematics of the tunable metasurface for the polarization conversion and the polarization rotation [85]; (g) schematics of polarization-sensitive IR metamaterials (PSIMs) [86]; (h-j) schematic of a tuning eSRR array by using comb drive horizontal tuning platforms [87][88][89].…”

Reconfigurable THz Metamaterial Filter Based on Binary Response for Information Processing System

“…Moreover, many studies reported numerous microelectro-mechanical-system (MEMS) based metamaterial and metasurface structures for numerous applications [18][19][20][21][22]. Ma et al [18] developed polarization-sensitive MEMS-based tunable metamaterials for the terahertz spectrum.…”

“…The lens was made of MEMS and has an optical power shift of more than 4% per 1 µm movement of the metasurface. In 2020, Huang et al [22] developed an actively tunable THz filter based on MEMS metamaterial. Due to the advantage in optical applications, electromagnetically induced transparency (EIT) analogues in classical oscillator systems were also discussed.…”

Multi-Band Electromagnetically-Induced-Transparency Metamaterial Based on the Near-Field Coupling of Asymmetric Split-Ring and Cut-Wire Resonators in the GHz Regime

“…Since then, the development of MM has been performed quickly and different kinds of MM were proposed, leading to many potential applications, such as MM perfect absorber [12,13], MM perfect lens [14,15], chiral MM [16,17] and MM wireless power transfer [18,19]. Besides the aforementioned applications, the EIT-MM also attracted great interest due to its simplicity in comparison with the original quantum systems [20][21][22][23][24][25].…”