Research On Thermal-optical Waveguide Switch Design And Drive Optimization Technology

With the rapid development of optical communication technology and the widespread application of high-capacity optical networks,the full opticalization of optical communication networks is the future direction.In a fully optical network,the optical switch is the core component of optical information exchange routing and has significant engineering application value.Among various typical optical switch types,the thermooptic switch based on optical waveguide has technical characteristics of low power consumption,small insertion loss,and ease of integration compared to other types,making it more suitable for applications in full optical networks.At the same time,the thermo-optic switch also has certain technical shortcomings in terms of state switching speed,which limits its application scenarios and requires relevant technical means to improve and enhance it.This thesis first conducts research on the principle of optical waveguide switches and analyzes the technical optimization characteristics of typical structures and materials of thermo-optic waveguide switches.After selecting silicon dioxide as the waveguide material,based on the single-mode transmission conditions of integrated optics,the rectangular waveguide structure is designed using the effective refractive index method.Then,the waveguide simulation model is established using simulation software to obtain the mode field distribution and transmission loss of the waveguide and to iteratively optimize the optical waveguide structure parameters.Based on the designed rectangular waveguide,a 3d B coupler is designed by combining the coupling mode theory with straight and curved waveguides,and further,the MZI-type thermo-optic switch model and overall parameter design are completed.Furthermore,based on thermodynamic knowledge,the thermal conduction equation and boundary conditions of the waveguide structure are analyzed.Based on the finite element method,the waveguide is modeled and simulated using Comsol software,and the thermal field distribution is analyzed.The electrode size,cladding thickness,and air slot width are optimized in the single-arm model.After obtaining the MZI structure parameters preliminarily,the structure is iteratively optimized again in the double-arm model to obtain the optimal structure parameters of the thermo-optic waveguide switch,which reduces the switch power consumption to 95 m W and decreases it by 53% after optimization.Subsequently,a technical approach based on pre-distortion drive is proposed and the technique is optimally designed.The scheme architecture of the predistortion drive technology and the analysis and calculation step method of key parameters are determined.Through simulation analysis,the pre-distortion drive scheme proposed in this paper achieves a better drive control effect,and the switching state switching time is reduced by 80% while maintaining a lower average power consumption.Based on this,the power gain range of the pre-distortion driving method is subsequently analyzed,and the switching state switching time can be further compressed and reduced to within 50 μs by using higher power gain within the tolerable range of waveguide structure and material.Finally,the simulation verification of the drive optimization technique is combined with Comsol to obtain the optimized design direction,which provides technical support for its subsequent related system design.The research results show that using pre-distortion drive control technology for thermo-optic waveguide switches can effectively reduce the state switching time of thermo-optic switches,while solving the contradictory heating and cooling issues of thermo-optic waveguide switches,improving the overall technical performance of the switches.