Active Multiple Plasmon-Induced Transparency with Graphene Sheets Resonators in Mid-Infrared Frequencies

A multiple plasmon-induced transparency (PIT) device operated in the mid-infrared region has been proposed. The designed model is comprised of one graphene ribbon as main waveguide and two narrow graphene sheets resonators. The phase coupling between two graphene resonators has been investigated. The multimode PIT resonances have been found in both cases and can be dynamically tuned via varying the chemical potential of graphene resonators without optimizing its geometric parameters. In addition, this structure can get multiple PIT effect by equipping extra two sheets on the symmetric positions of graphene waveguide. The simulation results based on finite element method (FEM) are in good agreement with the resonance theory. This work may pave new way for graphene-based thermal plasmonic devices applications

Tunable multimode electromagnetically induced absorption transmission in metal-insulator-metal resonators

The tunable multimode electromagnetically induced absorption (EIA)-like transmission was investigated in a two-ring system. In this system, by introducing asymmetry factor δi = λr - λr′, we provided several ways to modulate the EIA-like transmission spectra. An off-to-on EIA-like response could be realized by changing the radius or the refractive index of the rings. During the off-to-on process, we found the red shift and blue shift effects in the spectra are appeared and the widths of EIA-like dips are broadened. Numerical simulation by finite element method was conducted to verify our discussion. We believe all these would provide guidelines to design the useful EIA-like devices

Detuned Plasmonic Bragg Grating Sensor Based on a Defect Metal-Insulator-Metal Waveguide

A nanoscale Bragg grating reflector based on the defect metal-insulator-metal (MIM) waveguide is developed and numerically simulated by using the finite element method (FEM). The MIM-based structure promises a highly tunable broad stop-band in transmission spectra. The narrow transmission window is shown to appear in the previous stop-band by changing the certain geometrical parameters. The central wavelengths can be controlled easily by altering the geographical parameters. The development of surface plasmon polarition (SPP) technology in metallic waveguide structures leads to more possibilities of controlling light at deep sub-wavelengths. Its attractive ability of breaking the diffraction limit contributes to the design of optical sensors