ABSTRACT
Due to chemical CuPtB-type ordering of GaInP grown by metalorganic vapor phase epitaxy (MOVPE), the Td symmetry of the random zinc-blende alloy is reduced to C3v symmetry. Thus ordering leads to an uniaxial crystal, the ordering direction [111] being the extra-ordinary axis of the dielectric tensor. In ordered waveguide structures, the common TE/TM modes are replaced by new eigenmodes, the ‘super modes’, which are tilted with respect to the TE/TM orientations. Due to the different propagation constants for the super modes TE/TM polarization conversion is possible. Moreover, the propagation constants may be altered by applying an internal field using a pm-structure. A 1.77 mm long device based on an ordered double quantum well structure is presented which tunably converts TE and TM waves at an operating voltage of 4 V.
