Active Polarization Converter in AlGaAs

Asymmetric AlGaAs waveguides working in a cross-phase modulation regime and operated at photon energies below the band gap could be promising for the design of active TE-TM polarization converters. Crucially important for devices with asymmetrical cross-section is the orientation of the optical axes to maximize the TE-TM conversion. For [100] oriented AlGaAs angle-facet rib-waveguides, it is seen that the rotation of the polarization state is optimized if one optical axis of the device is aligned closed to the 45° polarization-maintaining axis in the bulk medium. The design of such a waveguide is illustrated at Fig. 1.