MZI-based PBS
Asymmetrical Mach-Zehnder Interferometer (MZI) structures on a sub-μ silicon-on-insulator platform are designed and analyzed when used as a polarization beam splitter (PBS). The analysis shows that it is allowed to use 2×2 power splitter/combiner couplers with a balanced ratio (50:50) for only one polarization by selecting the output ports for TE- and TM- polarizations appropriately. This makes the design much easier and more flexible.Compensating the positive or negative wavelength shifts due to fabrication errors is proposed by using a thermal-optical effect on the two MZI arms separately.
The schematic configuration of an MZI-based PBS
