On comparison of the temperature sensitivity of SU-8-based triple-arm MZI against straight rib optical waveguides patterned on silicon wafer

This study is performed to investigate the temperature sensitivity of SU-8-based triple-arm Mach–Zehnder interferometer (MZI) and straight waveguide. The proposed SU-8 2000-based rib waveguides are fabricated on a silicon wafer with 1.5-μm SiO2 thermal oxide layer. SU-8 layer of desired thickness is spin-coated onto the silicon wafer followed by patterning of the SU-8 waveguides. Temperature sensitivity of both waveguides is evaluated using the same heating source and under the same environmental conditions. Measurement results show that complex triple-arm MZI having different arm lengths offers a less linear sensitivity compared to the simple straight waveguide.