Patent ID: 7174071

Claim:
An arrayed waveguide grating (AWG) device comprising: a substrate having first and second slab couplers; a first array of waveguides optically coupled between the first and second slab couplers and having respective predetermined optical path length differences therebetween; a second array of waveguides optically coupled at first ends thereof to an input/output side of the second slab coupler, the waveguides of the second array being substantially tapered at first end portions thereof so as to increase in width towards the second slab coupler; wherein the separation distance between adjacent edges of adjacent waveguides at the first ends of the second array remains constant across the second array and the width of the first ends of the waveguides varies across the second array in a manner that increases, relative to constant width waveguide ends, uniformity across the second array of waveguides of a performance parameter selected from the group consisting of adjacent crosstalk (AXT), bandwidth (BW), Polarisation Dependent Loss, (PDL), Passband Uniformity (PBU).