  Carbon based optoelectronic devices promise to revolutionize modern
integrated circuits by combining outstanding electrical and optical properties
into a unified technology. By coupling nanoelectronic devices to nanophotonic
structures functional components such as nanoscale light emitting diodes,
narrow-band thermal emitters, cavity controlled detectors and wideband electro
optic modulators can be realized for chipscale information processing. These
devices not only allow the light-matter interaction of low-dimensional systems
to be studied, but also provide fundamental building blocks for high bandwidth
on-chip communication. Here we demonstrate how light from an
electrically-driven carbon-nanotube can be coupled directly into a photonic
waveguide architecture. We realize wafer scale, broadband sources integrated
with nanophotonic circuits allowing for propagation of light over centimeter
distances. Moreover, we show that the spectral properties of the emitter can be
controlled directly on chip with passive devices using Mach-Zehnder
interferometers and grating structures. The direct, near-field coupling of
electrically generated light into a waveguide, opposed to far-field fiber
coupling of external light sources, opens new avenues for compact
optoelectronic systems in a CMOS compatible framework.
