Abstract
A novel finite-difference time-domain modeling method is proposed to simulate the nonlinear electrodynamic responses of graphene at terahertz frequencies. The relation between currents in graphene and electromagnetic waves is governed by a $J\text{--}E$ characteristic formula at the frequencies where the conductivity of graphene exhibits resonant behavior. Simulation results demonstrate nonlinear phenomena in wave transmission through graphene including odd-harmonic generation and frequency-mixing effect. The proposed modeling method can be used as a full-wave solution to the design of nonlinear graphene-based structures.
Highlights
G RAPHENE, a two-dimensional material with interesting electromagnetic (EM) properties, has inspired researchers to propose linear graphene-based devices such as reflector [1], absorber [2], and isolator [3]
The band structure of graphene exhibits a linear energy dispersion relation near its Dirac points [4]. This linear band structure can theoretically lead to the suppression of ac electric current in graphene, and it results in the generation of odd harmonics under strong terahertz (THz) field illumination [5]
It has been predicted in [6] that a THz field with a peak value of 1 kV/cm is capable of inducing third-order harmonic generation (THG) on monolayer graphene at room temperature
Summary
G RAPHENE, a two-dimensional material with interesting electromagnetic (EM) properties, has inspired researchers to propose linear graphene-based devices such as reflector [1], absorber [2], and isolator [3]. The band structure of graphene exhibits a linear energy dispersion relation near its Dirac points [4] This linear band structure can theoretically lead to the suppression of ac electric current in graphene, and it results in the generation of odd harmonics under strong terahertz (THz) field illumination [5]. In terms of electric nonlinearity, a single time convolution approach has been used to analyze both Kerr and Raman interactions [17] As this model considers the case of nonresonant third-order processes [18], it is only suitable for optical spectra where graphene does not exhibit resonant nonlinear behavior [20]. The excitation of oddorder harmonics is successfully demonstrated, and the frequency mixing of two THz signals is presented
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
