Research On Hybrid Integrated MZI Optical Switching Device With Low Power Consumption Based On Polymer Composites

Integrated photon chips can integrate a variety of photonic devices on a single chip,with the advantages of small size,low power consumption,and high integration degree.As an important core component,hybrid integrated optical switches not only play the role of the switch protection but also can realize the optical switching with different materials,realizing the compatibility with different materials of the hybrid integrated chip.Optical switching devices require to having the characteristics of low power consumption,fast response,stable performance,large capacity,and low delay.Power consumption is an important practical indicator for the optical switch,and polymer optical switch has unique advantages in power consumption.Therefore,this article focuses on hybrid integrated optical switching devices with low power consumption based on polymer material.In terms of the device structure,the multi-dimensional MZI(Mach-Zehnder Interferometer)thermal optical switch with polymer/silica(Si O₂)hybrid integrated structure has been studied,which can solve the limitation of dimension in the planar chip.The proposed device can increase the vertical dimension through device hybrid integration,realizing the multi-layer interconnection structure of photonic devices,improving the integration degree of the chip.Meanwhile,the hybrid integrated switch uses the advantages of high thermo-optical coefficient of polymer and opposite thermo-optical coefficient of polymer and inorganic materials,realizing the complementary advantages of different materials,reducing the power consumption of the device.In terms of the materials,using the excellent optical properties of the graphene material,the polymer/Si O₂ three-dimensional(3D)hybrid integrated thermal optical switch based on graphene material has been studied.Then,to increase the thermal conductivity of the device materials,we study the graphene-doped polymer/Si O₂ thermal optical switch.The thermal conductivity of the polymer composite is improved,reducing the switching power consumption and response time.In terms of the control method,to achieve all-optical communication,based on the principle of thermal-optical effect,the Au-doped polymer/Si O₂ hybrid integrated all-optical switch has been studied.The main work of this paper is as follows:1.The 3D polymer/glass hybrid integrated thermal optical switch has been analyzed,which realizes an efficient coupling between the glass and the polymer waveguides in the vertical direction.The glass waveguide in the lower layer is prepared by ion exchange technology,which can realize a flat surface film,improving the coupling efficiency of the glass and the polymer waveguides.The power consumption and response time can be reduced because of the high thermo-optical coefficient of polymer material and the high thermal conductivity of inorganic material.The coupling between the polymer waveguide with step refractive index and the glass waveguide with graded refractive index has been calculated using COMSOL(COMSOL Multiphysics Modeling)software.This device could realize a 99.82%coupling with a window size of 3?m,an electrode width of 8?m,and a refractive index difference in the glass waveguide of 0.022.For the thermal optical switch with air trench and without air trench structure,The power consumption is 3.74 m W and 5.16m W respectively.The rise time(fall time)is 140.6?s(128.8?s)and 256.3s(249.5?s),respectively.2.From the perspective of the two-dimensional material,we study the hybrid integrated thermal optical switch based on graphene film.The performance of the device is improved by taking advantage of the optical properties of graphene film such as large thermal conductivity and broadband absorption.A flat waveguide surface could be obtained by spinning the polymer core layer material into the inorganic waveguide grooves,which benefit the compatibility between polymer material and inorganic material and transfer of graphene film.We first analyze the graphene optical absorption of base mode in the waveguide.Then,the proposed thermal optical switch is designed and optimized.Compared with the conventional thermal optical switch with a top electrode structure,the power consumption of the proposed switch decreases by 41.43%with an electrode horizontal distance of 4?m,a core layer width of 2?m,an electrode length of 1 cm,and a wavelength of 1550 nm.The rise time and fall time of the thermal optical switch are 64.5?s and 175?s,respectively.3.From the perspective of improving thermal conductivity,the graphene-doped polymer/Si O₂ hybrid integrated thermal optical switch is proposed.This proposed device solves the problems of film destruction and uneven waveguide surface when transferring the graphene film on the waveguide core layer.Use the graphene-doped polymer composite material as the cladding material of the device,improving the thermal conductivity of the composite material,reducing the response time and switching power consumption.The thermal conductivity of the composite material is analyzed using the Bruggeman model and Lewis Nielsen model,The thermal conductivity is increased by 133.16%with the graphene volume ratio of 0.236 vol.%.The power consumption of the thermal optical switch is 7.68 m W.The rise time(fall time)is 40?s(80?s).4.From the perspective of the control method,according to the principle of the thermal optical effect of polymer and photothermal effect of Au nanoparticles(Au NPs),we propose the Au nanoparticles-doped polymer/Si O2 hybrid integrated MZI photo-controlled optical switch.Firstly,the photothermal effect of the Au nanoparticles is analyzed according to the Au nanoparticles-doped waveguide device.Then,the Au-doped polymer/Si O₂ photo-controlled optical switch has been analyzed and optimized(base mode optical switch and first-order mode optical switch).The multiphysical field(light-heat-light)model of COMSOL is used to analyze the device photothermal effect and optimize the device performance.For the base mode switch,the loss of the E₁^x ₁mode and E₁^y ₁ mode is 0.29 d B/mm and 0.33 d B mm,respectively with a polymer core layer thickness of 0.5?m,a wavelength of 650 nm,a nanoparticles spacing of 1?m.The power consumption and rise(fall)times of the device are 2.05 m W and 17.3?s(106.9?s),respectively.For the first-order mode switch,the loss of E₁^x ₂ mode and E₁^y ₂mode is 1.07 d B/mm and 3.6 d B/mm,respectively with a nanoparticle radius of 10 nm,a wavelength of 532 nm,and a polymer core layer thickness of 4?m.The power consumption of the device is 0.5 m W(rise time:10.2?s,fall time:74.9?s).