A polarization controller includes a phase retarder having a rotation
about an {1,0,0} axis that receives an optical signal from a waveguide
structure. At least one nanoelectromechanical dielectric perturber
produces .+-.45.degree. birefringent axes by placing the at least one
nanoelectromechanical dielectric perturber at selective positions around
the phase retarder to produce dynamic change in the effective index in
one of the modes existent in an extraordinary axial direction.