Low-loss 1.5%-Δ arrayed waveguide grating with narrow laterally tapered spotsize converter

A low coupling loss of 0.5 dB/point between 1.5%-Δ silica-based waveguides and a singlemode fibre has been achieved by employing a simple laterally tapered waveguide with a narrow core width. By applying this structure to an arrayed waveguide grating multiplexer, the insertion loss was decreased from 4.9 to 2.6 dB.