Connectorized integrated star couplers on silicon

Abstract

A connectorized integrated <i>N</i> x <i>N</i> passive star coupler suitable for use in single-mode multichannel optical networks is reported. The excess loss for most of the channels of the coupler is within 1.5 dB, with a worst value of 3 dB, of the unconnectorized coupling values, which range from 14.5 to 17.5 dB. The optical fibers are attached to the 19 x 19 coupler by butt-coupling a linear array of single-mode fibers using silicon v-grooves. Alignment is rapidly achieved with a compact six-degrees-of-freedom piezo-controlled micromanipulator. Best values of less than 0.1 dB per fiber attachment, dependent on connector quality, were obtained. The coupler demonstrated negligible reflection effects when used as the central element in a 1-Gb/s frequency-division-multiplex network experiment.