Manipulation of polarization-dependent effects by magnetostrictive stress on silicon-on-insulator rib waveguides

Polarization dependent loss (PDL) can cause deterioration in optical network performance owing to the resultant fluctuation in received power because of random changes in fiber polarization. We describe the use of a magnetostrictive layer integrated on a planar light-wave circuit that can offer the functionality of modifying the variable PDL or differential group delay produced within the typical tolerances of volume manufacturing. This approach provides an alternative to the sizable delay lines and splitters that were previously employed for polarization compensation. We demonstrate adjustment of polarization-dependent parameters by the application of an external magnetic field to a ferromagnetic layer adjacent to the waveguide.