Band structure of one-dimensional photonic crystal with graphene layers using the Fresnel coefficients method

2018 ◽  
Vol 32 (11) ◽  
pp. 1850132
Author(s):  
A. Jafari ◽  
A. Rahmat

In this paper, we have calculated the band structure of an instance of one-dimensional photonic crystal (1DPC) composed of double-layered dielectrics via the Fresnel coefficients method. Then, we supposed the addition of a thin layer of graphene to each dielectric layer and the given photonic crystal (PC) composed of dielectric–graphene composites. The effects of graphene layers on the PC band structure were evaluated. We found out that according to the effective medium theory unlike the TE polarization, the electric permittivity of the dielectric layers changed at TM polarization. As such, the band structure of PC for TM polarization changed, too. Moreover, instead of bandgap related to “zero averaged refractive index” an approximately omnidirectional bandgap appeared and a related bandgap to “[Formula: see text] = 0” disappeared. In addition, a new angular gap branch appeared at a new frequency at TM polarization in which the width of gap increased as the angle increased.

2018 ◽  
Vol 32 (01) ◽  
pp. 1750277
Author(s):  
A. Jafari ◽  
A. Rahmat ◽  
S. Bakkeshizadeh

We consider a one-dimensional photonic crystal (1DPC) composed of double-layered dielectrics. Electric permittivity and magnetic permeability of this crystal depends on the incident electromagnetic wave frequency. We suppose that three level atoms have been added to the second layer of each dielectric and this photonic crystal (PC) has been doped. These atoms can be added to the layer with different rates. In this paper, we have calculated and compared the band structure of the mentioned PC considering the effect of added atoms to the second layer with different rates through the Fresnel coefficients method. We find out that according to the effective medium theory, the electric permittivity of the second layer changes. Also the band structure of PC for both TE and TM polarizations changes, too. The width of bandgaps related to “zero averaged refractive index” and “Bragg” increases. Moreover, new gap branches appear in new frequencies at both TE and TM polarizations. In specific state, two branches of “zero permittivity” gap appear in the PC band structure related to TM polarization. With increasing the amount of the filling rate of total volume with three level atoms, we observe a lot of changes in the PC band structure.


2012 ◽  
Vol 285 (9) ◽  
pp. 2439-2444 ◽  
Author(s):  
S. Gutiérrez-López ◽  
A. Castellanos-Moreno ◽  
A. Corella-Madueño ◽  
R.A. Rosas ◽  
J.A. Reyes

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Zhiwei Zheng ◽  
Leyong Jiang ◽  
Jun Guo ◽  
Xiaoyu Dai ◽  
Yuanjiang Xiang

The optical bistability in one-dimensional photonic crystal (1DPC) with a nonlinear defect is investigated. It is demonstrated that, by introducing graphene layers into the nonlinear defect, the optical bistability in 1DPC can be changed significantly. The hysteresis threshold increases with the number of graphene monolayers and can be lowered or enhanced by tuning the Fermi energy of graphene. On the other hand, the hysteresis width and the nonlinear lateral shift can also be controlled by varying the Femi energy and the number of graphene monolayers. These results may be useful for controlling the optical bistability and nonlinear lateral shift in 1DPCs.


2003 ◽  
Author(s):  
Shailendra K. Varshney ◽  
Mukesh P. Singh ◽  
Ravindra K. Sinha

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