Research On Graphene-assisted Polymer Thermo-optic Switch

In recent years,with the rapid development of communication technology,people have put forward higher requirements for the speed and stability of data transmission.As an emerging technology,optical interconnection relies on the large data transmission capacity and relatively high data transmission capacity of integrated optical circuits.Strong anti-electromagnetic interference ability is gradually becoming the mainstream direction of a new generation of chips.In the integrated photonic chip,the optical switch plays the role of controlling the on-off and switching of the chip,and is an important part of the realization of full-off signal routing and switching.At the same time,silicon photonics,with its unique advantages such as high integration density and compatibility with complementary metal oxide semiconductor(CMOS),provides reliable technical support for the high integration of optical switches,and is expected to break the bottleneck of integrated electronic chip response speed and power consumption.With the high integration and density of optical chips,a large number of optical switches need to be applied to optical chips to achieve more precise control and diversified functions.Therefore,the performance indicators of optical switches play an important role in the field of optical chips.The role of.In order to study the optical switch with fast response speed and low power consumption,researchers have done a lot of research on the structure and preparation materials of the optical switch.Because graphene materials have excellent physical,electronic and optical properties,they are widely used in the field of optical switches,which further improves the performance of optical switches.In this paper,using graphene's high thermal conductivity and excellent electrical properties,graphene is applied to thermo-optical switches to improve the working efficiency of thermo-optical switches,The main contents include:1.A low-power polymer MZI thermo-optical switch with a working wavelength of 532 nm was prepared in the experiment.The photosensitive polymer material SU-8is used as the waveguide core layer,silicon dioxide is used as the substrate,and PMMA is used as the upper cladding layer.The waveguide core layer was prepared by wet etching,then PMMA was spin-coated as the upper cladding layer,and finally aluminum electrodes were prepared by vacuum coating.The prepared switch was tested under 532 nm signal light,the power consumption was 6.55 m W,the extinction was 4.8 decibels,and the rising time was 0.23 ms,the falling time was 0.28 ms.On the basis of the above experiments,combined with ultraviolet writing technology and graphene thermal conductivity layer,an optimized switch structure is proposed.In order to reduce power consumption and switching time,side electrodes are designed.After calculation,the optimized device power consumption is 1.5 m W.The simulated ultraviolet writing device has a rise time of 18.2?s and a fall time of 85?s.The device has broad application prospects in the field of wearable devices and lidar.2.A graphene-assisted first-order mode thermo-optical switch is proposed.In this part,we propose a graphene-embedded polymer Mach-Zehnder interferometer(MZI)thermo-optic switch,which solves the contradiction between high heating efficiency and low transmission loss.The switch adopts a three-dimensional structure to achieve MZI optical signal modulation,and graphene is embedded in the center of the waveguide as an electrode material for efficient heating.In order to solve the problem of graphene's absorption of optical signals,we pass the signal light through a mode converter,thereby converting it into the TE1 mode,and modulating it as the next signal light.Using the optical signal in TE1 mode can minimize loss and power consumption.We simulated the center-embedded graphene electrode structure using the finite element method,and its absorption loss was 0.06 d B/cm,and the calculated power consumption was 1.57 m W.The proposed graphene embedded device has lower power consumption,which is reduced by 74%when compared with the traditional top heating electrode with the same structural parameters.In addition,the rise time of the graphene-embedded thermo-optic MZI switch is simulated as 1.2?s and the fall time is 70.6?s.The device can be applied to the field of two-dimensional integrated low-power mode division multiplexers.3.A polymer thermo-optical mode switch based on two vertical Mach-Zehnder interferometer structures is proposed.In this switch,two MZI structures are vertically distributed,and each MZI modulation arm has an electrode.When the signal light passes through two Y branches,it is equally divided into 4 parts,and then passes through the second group of Y branches to merge.By controlling the on and off states of different switches,it can realize fast switching between E₀₀,E₀₁,E₁₀and E₁₁.In this part,the performance of the mode selection switch of the two structures(metal top electrode and graphene electrode)is compared,and the parameters of the graphene electrode device are simulated and calculated by the finite element method.The rise time of the mode selection switch is 36.9?s and the fall time is 103.4?s,The power consumption is 1.85 m W.In addition,the calculated rise time of 1 and 3 graphene heater mode switches is 36.9?s and the fall time is 103.4?s,respectively,and the calculated rise time of 2 and 4 graphene heater mode switches is 17.3?s and the fall time is 87.9?s.This model can be used in the field of low-power mode division and three-dimensional integrated multiplexers.