SIMPLE AND LOW-LOSS FIBER-TO-CHIP COUPLING BY INTEGRATED FIELD-MATCHING WAVE-GUIDE IN INP

A nested taper structure in InGaAsP/InP, using only horizontally taper ed waveguides, transforms the fundamental mode of an integrated wavegu ide to the mode profile of a singlemode fibre. Taper tips below 300 nm width have been achieved with standard technology. Very first measure ment results show an insertion loss of only 4 dB for a 1 mm long devic e without any antireflective coating or immersion fluid.