Light-controlled Characteristics Of Integrated Optical Waveguide Based On Microfiber

Optical waveguide determines the propagation direction of the light,which is confined in optical waveguide or surrounding.Waveguide optics is a discipline that study the optical transmission characteristics and applications of the optical waveguide.Generally,waveguide optics is divided into two branches: optical fiber optics and integration optics.Optical waveguide principle and the research results of the device is widely used in the areas of information retrieval,transmitting and processing.In optical fiber systems,microfiber has many fascinating features such as flexible configurability,high uniformity,low transmission loss,stable physical and chemical performance,tight optical confinement,and robust evanescent fields.First,microfiber-graphene integrated devices was fabricated by using microfiber attached onto polydimethylsiloxane(PDMS)supported graphene substrate.Waveguide-coupled graphene make graphene interact with a guided waveguide mode wave.Then,we optimize the structure of microfiber on graphene/PDMS substrate with PDMS-clad.Futherly,the optical device is fabricated by the waveguide coupled Au/graphene film with PDMS-clad.The improvements above enhance the light-graphene interaction.The graphene exhibit obvious optical polarization effect and saturable absorption effect.The control of the light is realized by the optical waveguide based on graphene.The structures and their performances,as introduced below:1.We experimentally investigated microfiber on graphene integrated optical waveguide exhibit the high polarization extinction ratio(ER)and saturable absorption.It has the polarization ER maximum 31.0 dB@1550 nm,25.0 dB@1310 nm,16.0dB@980 nm with the optimal diameter value(3.9 ?m).The transmission with 3 dB and 10 dB change at 980 nm in the S-polarization mode is reached in need of input power 15.1 mW and 66.1 mW.2.We optimized a structure of microfiber on graphene/PDMS substrate(MGPS)with PDMS-clad.The weak light coupled into the device shows a strong polarization effect with the maximum ER of 47 dB@1550 nm.Using a two-color pump-probetechnique,we experimentally demonstrated all optical fiber modulator based on polarization dependent saturable absorption in graphene.The S-polarization of the pump light and signal light interact with graphene,which can improve the efficiency of the light in modulator.3 dB,10 dB,and 20 dB modulated of the transmission change need pump light 5.8 mW,21.0 mW,and 57.0 mW,respectively.3.Optical device is fabricated by the waveguide coupled Au/graphene film with PDMS-clad.The Au/graphene keep the form of the plane.The polarization ER can be up to ~42.3 dB@1550 nm;The results show that the maximum transmission change with 41.0 dB is reached in need of 980 nm pump light 130 mW.3 dB and 10 dB modulated of the transmission change need pump light 2.8 mW and 5.6 mW,respectively.The gold film can confine the evanescent field and enhance light-graphene interaction.In a word,the integrated optical waveguide structure combines the microfiber and graphene photoelectron.In principle,it can achieve more than 100 GHz ultrafast optical signal control.It can allow multiple functions of signal emitting,transmitting,modulating,and detection to be realized.It will be have a very important application in optical communication,sensors,and ultrafast lasers in future.Second,we also proposed a interferometer consisting of a section of tapered seven core fiber spliced between two pieces of single mode fiber.Through the substrate effect,the resonant contrast and the maximum attenuation peak of the transmission spectrum depend on the polarization angle of the polarized light.A highly sensitive temperature sensor based on the tapered MCF interferometer embedded in PDMS is experimentally demonstrated.The temperature sensitivity of our sensor can reach on 11714 pm/? in the range of 25 ? to 45 ? and is higher than optical fiber temperature sensors reported previously.We believe that our sensor is good candidate for biological applications or PDMS microfluidic circuits.