Conversion of light polarisation in asymmetric plasmonic waveguides

Hybrid plasmonic waveguides with an embedded conducting oxide layer can be used for producing fast and compact electro-optical modulation devices. However, due to constraints, which plasmon modes impose on light polarisation, modulators of this class are not compatible with high-efficiency modern diffraction gratings used for coupling light into a waveguide. In the present work we demonstrate how a simple structuring of a modulation sandwich makes it possible to produce a compact polarisation converter that eliminates the mentioned incompatibility.