Low switching power 2 × 2 thermo-optic switch using direct ultraviolet photolithography process

A Multimode Interferometers–Mach Zehnder Interference (MMI–MZI) polymer 2 × 2 thermo-optic switch is proposed using the thermo-optical effect of polymer materials and fabricated by simple direct ultraviolet photolithography process. We utilize a cross-linkable negative photoresist as core material. Once exposed to ultraviolet light through a photomask, the waveguide strips can be obtained upon development. The experiment results show that the switch has a low switching power of less than 7.5 mW.