Diffraction grating based fibre-to-waveguide coupler for polarisation independent photonic integrated circuits

摘要

The present invention provides a waveguide coupler, comprising:a substrate;two waveguides (25,26) formed on said substrate intersecting at a right angle; anda diffraction grating structure (19) formed at the intersection of said waveguides.;It is an advantage of the present invention that a polarisation splitter is obtained, which couples orthogonal modes from a single-mode optical fibre into identical modes of two planar waveguides. It may be used in a polarisation diversity configuration to implement a polarisation insensitive photonic integrated circuit based on diffraction grating structures, such as photonic crystals.