Basic Research On The Application Of Graphene In Tunable Optical Devices

The properties of high carrier mobility,broadband absorption and transparency make graphene a promising optoelectronic material for the development of high-speed tunable CMOS-compatible silicon-based light sources and modulators.The electrical and optical properties of graphene have been further studied in this paper.On the basis of this,systematic researches have been carried out in the fields of electric absorption modulator,nanoantenna enhanced silicon waveguide modulator and high-speed tunable MIS tunneling light source.The main contents and innovations of the study can be summarized as follows:1.A new hybrid SPP waveguide modulator is proposed.Compared with the traditional SPP waveguide modulator,the horizontal placement of the hybrid SPP waveguide structure makes the electric field component of the light mode in the SPP waveguide mainly distributed in the graphene surface,which enhances the interaction between light and graphene.Finally,a 400 GHz modulation rate and 1.6 ?m2 compact size of the electrical absorption modulator is achieved.2.A novel electro-optic modulator with ultra-thin metal patch antenna is proposed.This design combines the characteristics of effective coupling between the TE mode in the waveguide and both sides of the ultra-thin metal patch antenna,so that a small number of antennas can provide a strong localized plasmon resonance.Moreover,the field components of the resonance mode are mainly distributed in the graphene surface,enhancing the light-graphene interaction.Finally,a modulator with a modulation rate of 400 GHz,a power consumption of 0.5 f J/bit, and a modulator length of 500 nm is achieved.3.An nanoantenna enhanced MIS tunneling light source loaded with graphene electrode is proposed.The low internal quantum efficiency caused by the low proportion of inelastic tunneling electrons and the low photonic radiation efficiency caused by the mismatch of wave vector are solved,and a high-speed CMOScompatible tunneling light source is realized by using the properties of the optical transparency and fast switching of graphene.Finally,in the optical communication frequency band,the radiation power of the light source is 8000 times higher than that of the dipole excitation source in the free space,and 510 times higher than that of the traditional MIS tunneling light source.Moreover,the working frequency and output power of the light source are tunable.