International Journal of

By developing the terahertz (THz) technology, in addition to generators and detectors of THz waves, the existence of some tools such as modulators and filters are needed. THz filters are important tools for various applications in the field of chemical and biological sensors. Linear and nonlinear optical properties of the graphene have attracted lots of attention. In fact graphene exhibits various nonlinear phenomena. Hence in this paper, by entering the graphene to the field of THz and using the graphene nonlinear properties with utilizing the transfer matrix method and transmission properties of a periodic structure containing graphene are investigated. A fairly straightforward computational method allows us to examine the effect of different structural parameters on the transmittance spectrum. Simulation results show that if the graphene nonlinear response in a periodic structure in the presence of a high-intensity THz field is considered, the proposed structure displays two bands of passes and stopping which can improve the design of the filters and controllers of THz waves.

In a ring laser gyroscope, due to the rotation and the Sagnac effect, a phase difference between the two counter-propagating beams is generated. In this device, the higher phase difference between these two beams causes the better the interference pattern detection, and thus the sensitivity is increased. In this paper, the effect of inserting a dielectric-graphene photonic crystal inside a ring laser gyroscope on the interference pattern and the sensitivity of the device are studied and simulated using ABCD propagation matrix method. Results show that dielectric-graphene photonic crystal has a high transmission and therefore high efficiency in the wavelength of ring laser gyroscope. So it is a suitable choice to use in the ring laser gyroscope. Also, a comparison between ring laser gyroscope with and without dielectric-graphene photonic crystal shows that when the dielectric-graphene photonic crystal is in the system it is possible to build gyroscope with smaller lengths and high sensitivity.