A low-power 1×2 polymeric thermo-optic switch with a trench structure is proposed and fabricated. The trench structure in the optimized region slows down the heat flow from the electrodes, which contributes to the reduction of power consumption. The temperature distribution in the polymer layers has been adjusted to increase the temperature gradient between the two arms of the Y-branch. For comparison, a 1×2 polymeric thermo-optic switch with no trench structure is fabricated together on the same substrate. In the device with a trench structure, the measured crosstalk is less than -14 dB for TE polarization. The power consumption is about 40 mW, which is almost 2/3 of that of the device with no trench structure.
