| Analysis of optical bistability of a single layer graphene for TE and TM mode polarizations at terahertz frequencies |
| Paper ID : 1348-UFGNSM-FULL (R2) |
| Authors: |
|
Mehdi Sadeghi *1, Vahid Ahmadi2 1Tehran
Jalal AleAhmad
Nasr
P.O.Box: 14115-111 2Faculty of Electrical and Computer Engineering, Tarbiat Modares University, Tehran, Iran |
| Abstract: |
| The ongoing progress of optical systems need for designing fast, low power optical switches becomes inevitable. The main obstacle in this trend is the lack of a material or structure that can overcome ordinary materials shortcomings which include bulkiness and requirement for high input power to trigger its nonlinear optical effects. Graphene is a single sheet of carbon atoms with honeycomb pattern which possesses a giant third-order optical susceptibility especially at terahertz frequencies which intraband transition of electrons is dominant. So it has been proposed by researchers to be used as the material for bistable optical devices. Here, we theoretically and numerically compare the optical bistability for the TM and TE modes in the single layer graphene structure surrounded by two dielectrics for different values of the Fermi energy level, incidence angle and dielectric functions by solving Maxwell equations. The results show that to have low threshold optical bistability with appropriate hysteresis width, we should increase the first media dielectric function and decrease the Fermi level and incidence angle for TE mode and increase the first media dielectric and decrease the Fermi level for TM mode. We have also shown that we can decrease the threshold for the optical bistability three orders of magnitude from zero incidence angle condition by choosing suitable values for the incidence angle, Fermi level and dielectric functions at 1 THz. frequency. The emergence of the electron interband trasition is the only confining factor to reduce the Fermi level of the graphene layer. Simulation results show that graphene is an astonishing candidate for future very low power optical bistable devices at terahertz frequency ranges. |
| Keywords: |
| graphene- kerr effect- optical bistability |
| Status : Paper Accepted (Poster Presentation) |
