Quadruple plasmon-induced transparency and tunable multi-frequency switch in monolayer graphene terahertz metamaterial

Abstract

A monolayer graphene metamaterial composed of a graphene block and four graphene strips, which has the metal-like properties in terahertz frequency range, is proposed to generate an outstanding quadruple plasmon-induced transparency (PIT). Additional analyses show that the forming physical mechanism of the PIT with four transparency windows can be explained by strong destructive interference between the bright mode and the dark mode, and the distributions of electric field intensity and electric field vectors under the irradiation of the incident light. Coupled mode theory (CMT) and finite-difference time-domain (FDTD) method are employed to study the spectral response characteristics of the proposed structure, and the theoretical and simulated results are in good agreement. It is found that a tunable multi-frequency switch and excellent optical storage can be achieved in the wide PIT window. The maximum modulation depth is up to 99.7%, which corresponds to the maximum extinction ratio of 25.04 dB and the minimum insertion loss of 0.19 dB. In addition, the time delay is as high as 0.919 ps, the corresponding group refractive index is up to 2755. Thus, the proposed structure provides a new method for the design of terahertz multi-frequency switches and slow light devices.

Triple-Band Surface Plasmon Resonance Metamaterial Absorber Based on Open-Ended Prohibited Sign Type Monolayer Graphene

“…Furthermore, by using the control variable method, we studied the effect on the absorption by adjusting the geometric parameters [ 48 ], the opening width a , the cross-width b , the ring width w , and the inner radius r . The corresponding results are suggested in Figure 7 .…”

“…However, the pattern size of OPST graphene should not be too large, as this can cause it to couple to adjacent graphene arrays and affect the resonance frequency. Furthermore, by using the control variable method, we studied the effect on the absorption by adjusting the geometric parameters [48], the opening width a, the cross-width b, the ring width w, and the inner radius r. The corresponding results are suggested in Figure 7. Figure 7a,c,e,g displays the changes in absorption efficiencies of each resonance mode, and Figure 7b,d,f,h shows the corresponding shift of the resonant frequency.…”

Polarization-sensitive multi-frequency switches and high-performance slow light based on quadruple plasmon-induced transparency in a patterned graphene-based terahertz metamaterial

“…Recent research found that m can reach a maximum value of 4.0 m 2 V À1 s À1 at room temperature. 45,46 Thus, it is reasonable to set the graphene carrier mobility m to 4.0 m 2 V À1 s À1 .…”

Multifunctional terahertz device based on plasmon-induced transparency

“…PIT-effect metamaterials are renowned for their extensive potential in various fields, including modulators [36], encoders [37], and sensors [38]. Their unique feature of creating a transparent window significantly slows down photon propagation through the medium, setting a solid groundwork for future advancements in optical communication and storage technologies.…”