Design Of Graphene Optical Modulator

With the continuous increase of silicon semiconductor process size,the quantum effect of matter gradually appears,quantum tunneling makes the integrated circuit work unstable.In recent years,with the rapid development of optical fiber communication technology and the deepening of modern optical research,it is possible to integrate photoelectric semiconductor,which provides a new way for the development of integrated chips.Electro-optic modulator,as the core device of optoelectronic integrated chip,has been widely concerned by scholars in recent years.In recent years,a variety of electro-optic modulators have been designed,but these modulators still have some problems.Firstly,the device size is too large,and the device size and performance are not good.Secondly,the high driving voltage can not realize the direct drive of electric chip.In view of the problems found in this article from the electro-optic modulator first-order electro-optic effect principle,analyze the modulation unit electrode and the waveguide coupling coefficient can be greatly enhanced by means of double stack waveguide,and design the double stack waveguide optical modulation unit,and the design of the modulation unit theoretical derivation and simulation verification,realized the modulation unit length is reduced to 1 mm,The width is reduced to 5um.The reference formula and field intensity distribution diagram of lumped electrode design are obtained by analyzing the electric field of electrode,which provides more accurate theoretical basis for electrode design.In order to match the electro-optic modulator unit designed in this paper,couplers and beam splitters suitable for double waveguide stack structure are designed.Firstly,three existing beam splitters are analyzed and their advantages and disadvantages are summarized.By improving the structure of two-dimensional Y beam splitter,triangular beam splitter and coupler structure suitable for double waveguide stack structure are designed.The feasibility of the design scheme is verified by simulation,and the beam splitting and coupling of the three-dimensional waveguide structure are realized.Finally,a high speed and low power stereo graphene modulator is designed and simulated using the designed electro-optic modulation unit and beam splitter coupler.The overall length of the modulator is 1.14 mm,width is 10 um,and height is 4.3um.The half-wave voltage of the modulator is 5.5V,extinction ratio is-18 d B,insertion loss is 1.15 d B,echo loss is-44.8dB,modulation depth is 0.015,modulation bandwidth is58.8Ghz.