Elimination of PD-λ at all output ports of silica-based AWG

It is shown that the polarisation dependent wavelength shift (PD-λ) of a silica-based arrayed waveguide grating (AWG) is proportional to its output port location as a result of the birefringence in a slab waveguide. This PD-λ was eliminated to less than 0.01 nm by inserting a half waveplate across the slab waveguide.