Study On Thermo-optic Tuning Devices Based On Polymer Waveguide

Thermo-optic tunable waveguide devices have promising applications in optical communications and microwave photonics. High integration and low power consumption are the inevitable trend of tunable optical waveguide device development. By its high thermo-optic coefficient, low cost and good fabrication compatibility, polymer is a good choice for material of thermol-optic tunable optical waveguide devices. The thesis presents the research on the thermo-optic tunable waveguide devices based on a new polymer material PSQ-Ls. The highly efficient and low thermal crosstalk structures of waveguide and microheater were obtained through the thermo-optic effect simulaiton. The micro-ring based tuanble filters with different function were optimized and the Mask of device layout for fabrication was designed.Firstly, the filter principle and application of the micro-ring based waveguide filters were analyzed. The parameters of filter performance were introduced. The Mach-zehnder Interferometer (MZI) was proposed to replace the conventional direction coupler to meet to the requirement of tunable filter in the practical applications. The tunability of coupling coefficient and resonant wavelength was realized by the thermo-optic effect of waveguide with microheaters, which was utilized in the microwave photonic signal processing. The design target for filter performance improvement was given.Secondly, according to the two dimension thermal field model of the polymer waveguide with microheater, the thermo-optic tuning efficiency and thermal crosstalk were simulated with the softwaves of Comsol-multiphysic, Matlab and Rsoft for thermal analysis, data processing and waveguide design, respectively. With MZI based tunable coupler as the project, the influence of microheater and wavegudie structures on the thermo-optic tuning efficiency was ananlyzed. The high efficiency, small size structures of microheater and waveguide were obtained with the endurable temperature increase of waveguide materimal. The thermal crosstalk of the microheater to the nearby waveguide was simulated with different distance betweent the microheater and the waveguide. The optimized distance value was achieved with negligible thermal crosstalk. Finally, the structures of three type tunable filters with micro-ring, notch filter, Add-Drop filter and MZI+ring bandpass filter, were optimized according to the above microheater design result. The Mask of device layout of the three filters and funciton units for fabrication was designed, which gave a good foundation for further device fabrication and application.