CHARACTERIZING POLARIZATION-BASED DESIGNS OF UNBALANCED MACH-ZEHNDER INTERFEROMETERS

We have experimentally investigated and simulated the diversity of unbalanced Mach-Zehnder interferometer (UMZI) designs. The group index and free spectral range (FSR) are measured for both the transverse electric (TE) and transverse magnetic (TM) designs for a silicon (Si) strip waveguide that has a 500 nm width and a 220 nm height. The simulated TE UMZI with arm's length difference of 50 µm shows 11 nm and 4.33 of the FSR and group index, respectively. The group index is 3.103, and FSR is 13.5 for the TM UMZI. These designs show a slight variation compared with the simulation results due to fabrication variation. Overall, the TM UMZI design is more sensitive to the manufacturing variation than the TE UMZI designs. Photonic interferometers have been widely used in photonic devices, and such photonic devices have potential applications in photonic modulators, sensors, filters, and future computing via photonic integrated circuits (PICs)