Ultracompact microring laser-based optical-add multiplexer

A highly compact and scalable micro-ring-laser-based optical-add multiplexer is presented for wavelength division multiplexed bus networks. The output of a 40 mm-radius micro-ring laser is vertically coupled to a passive waveguide bus and the chip is subsequently mounted in a butterfly package with fibre pigtailing at both input and output. In the first such experiment with a micro-ring-based module, a wavelength channel is added into a wavelength multiplexed fibre-optic link with negligible power penalty. Successful transmission of a 2λ x 2.5 Gbit/s signal over 25 km is demonstrated for a 0.9 nm channel spacing.