Polarization dependent loss may be reduced by providing at least one dummy
waveguide or at least one dummy metal structure. Polarization dependent
loss may also be reduced by imposing a mechanical force on the OIC to
exert mechanical stress thereby changing at least one of the
birefringence and the optical axes of at least one waveguide. And
polarization dependent loss may be reduced by forming a metal heater
using a first set of metal deposition parameters; forming a conductive
metal structure contacting the metal heater using a second set of metal
deposition parameters; and selecting the first set of metal deposition
parameters and the second set of metal deposition parameters to reduce
stress.