Fibre-optic polarisers and polarising couplers

Abstract

The dispersion equation describing the planar waveguiding properties of a thin metal film sandwiched between two dielectrics was used to predict the conditions for polarisation selective coupling from an optical fibre to surface plasmon polaritons. The conditions predicted by the analysis and those found by experiment were in close agreement and the results led to the realisation of a high-quality polariser and polarising coupler demonstrating extinction ratios in excessof 50 dB (at 1.3 micron) and 30 dB per arm (at 1.3 micron) respectively.