Study On Photonic Devices Of Graphene Based On Optical Tamm States

In modern society,optical communication technology plays a more and more important role in people's life.Therefore,the development of optical communication technology to improve the efficiency and speed of the all-optical network has become an urgent problem to be solved in today's society.The development of optical communication technology can not be separated from optical signal processors.Optical switches and optical modulators are important components of optical signal processing devices.Optical switch is the key device of a new generation of all-optical networks,mainly used to achieve all-optical hierarchical routing,wavelength selection,optical cross connect,self-healing protection functiond and so on.Optical modulator can ultimately control the refractive index,absorption,amplitude,or phase of the output light by the change of voltage or electric field.As a new type of local boundary mask,OTS can be excited simultaneously by TE and TM polarized light in planar structure and the incidence angle and dispersion control element need not be specific.Based on the characteristics of Optical Tamm States in metal-DBR structure and the unique properties of graphene,a graphene optical switch based on optical tamm states and a graphene optical modulator based on optical tamm states are proposed and designed.The specific research contents are as follows:(1)OTS shows good optical properties in the study of photonic crystal heterostructures and photonic crystal-metal structures.This paper mainly studies the OTS in the M-DBR structure,as well as the formation mechanism and theoretical model of OTS,and uses the COMSOL simulation software to build the model.By simulating the factors that may affect the OTS local effect in the M-DBR structure,we get the best structure of the metal-DBR model by comparing the reflected spectrum and the electric field distribution map.(2)Graphene layer is introduced into the M-DBR structure and the optical switch of graphene based on optical Tamm state is introduced.With the intrinsic wavelength of OTS as the incident wavelength,when the external driving voltage is 0V,the reflectivity of the intrinsic wave length of the OTS is the lowest and the optical switch is in the "close" state.The dip peak of OTS is drifting when the external driving voltage is larger than the abrupt voltage of the graphene index.The reflectivity of the intrinsic wave length will rise from the lowest point to the high reflection area and the optical switch is in the "open" state.Finally,the purpose of the control is to be achieved.The insertion loss,extinction ratio and response time of graphene optical switches based on optical Tamm states were studied.(3)A graphene optical modulator based on the optical tamm states is proposed by changing the position and number of the graphene layer.The principle of the graphene modulator based on OTSis analyzed.The main purpose is to make use of the unique electrical control property of graphene materials.The graphene will change the refractive index after the applied driving voltage,which will make the dip peak of OTS drift.Finally,the strength modulation can be achieved by using this feature.The modulation depth,insertion loss,extinction ratio and modulation rate of the graphene modulator based on optical tamm states are studied respectively.(4)The work of this article is summarized and the future work is prospected.