Thermal performance analysis of polymer optical waveguides for thermo-optic applications

This work presents a detail numerical investigation of thermal performances of various optical waveguides using the finite element method. As the key performance indicator of thermo-optic devices, switching time and power consumption is considered for the analysis. The waveguides under investigation consist of two different material compositions: silica as a cladding layer with polymer core and all-polymer waveguide. The waveguides with silica cladding show faster switching time than that with polymer cladding due to the high thermal conductivity of silica. On the other hand, all-polymer waveguides need less power to achieve the desired temperature than the silica counterpart. The thermal performance are investigated for each type of waveguides by varying the upper and lower cladding thickness, being the controlling parameters. The switching time is increased with the increasing of upper cladding thickness, whereas, it remain constant for the changes in lower cladding thickness. However, considering power requirement, the thicker lower cladding reduces the power consumption. From the temperature distribution of different waveguides (e.g., ridge, strip and rib), it is observed that the ridge waveguide requires less power to attain the desired temperature than the strip and rib waveguides. Such analysis results would help to optimize the waveguide geometry and thus to further enhance the overall performance of thermo-optic devices.