Research On Optical Absorption Of Graphene-silicon Hybrid Waveguide

Photon technology is a comhensive technology developed on the basis of modern integrated optics.Utilizing photon as the carrier of information,the data transmission solution based on photon technology has the advantages of fast transmission speed,large transmission bandwidth,strong anti-electromagnetic interference ability,low power consumption and so on.As a branch of integrated optics,the silicon photonics is of the most potential to make great break throughs,of which the main route is to make full use of existing CMOS(Complementary Metal Oxide Semiconductor)technology to fabricate photonic-integrated devices.After decades of development,silicon photonics has made a series of major achievements in optical interconnection,optical sensing and optical computing etc..Silicon based modulator,filters,detectors,lasers and other key components have all been invented,some of which have even reached the commercial standard.However,due to the limitation of the material itself,the silicon photonic devices can hardly be used in light source and usually perform a narrow bandwidth.Graphene has received a lot of concerns in recent years,of which the unique photoelectric properties make it potential for optical signal processing.Integrating graphene onto the optical waveguide can not only enhance the interaction between graphene and light,but also could control the transmission properties of the waveguide,and thus promote the performance of silicon based photonic devices.Actually,graphene based optoelectronics can always have a broad bandwidth due to its zero bandgap,and the saturable absorption of graphene makes it applicable for mode-locked lasers,which are of great strategic significance for the development of future all-optical interconnection chip.This paper focuses on integration of graphene and silicon based optical waveguide devices.The optical transmission properties of silicon microring resonator and graphene have been presented based on the lastest international research results.The silicon-graphene hybrid waveguide devices have also been fabricated and tested in this paper.For the first time,the linear absorption coefficient of graphene has been accurately measured utilizing a silicon microring resonator,the concept that silicon microring resonator can enhance graphene's absorption has been proposed,the side-wall-graphene's contribution to whole absorption of the hybrid waveguide has been considered.A saturable absorber on chip based on silicon-graphene hybrid waveguide has also been fabricated in this paper,of which the modulation depth is as large as 25%.