The integration of optical interconnects in printed circuit boards (PCB) is a rapidly growing field due
to a continuously increasing demand for high data rates, along with a progressive miniaturization of
devices and components. For high-speed data transfer, materials and integration concepts are
searched for which enable high-speed short-range connections, accounting also for miniaturization,
and costs. Many concepts are discussed so far for the integration of optics in PCB: the use of
optical fibers, or the generation of waveguides by UV lithography, embossing, or direct laser writing.
Most of the concepts require many different materials and process steps. In addition, they also
need highly-sophisticated assembly steps in order to couple the optoelectronic elements to the
An innovative approach is presented which only makes use of only one individual inorganic-organic
hybrid polymer material to fabricate optical waveguides by
two-photon absorption (TPA) processes.
Particularly, the waveguides can be directly integrated on
pre-configured PCB by in situ positioning
the optical waveguides with respect to the mounted optoelectronic components by the TPA
process. Thus, no complex packaging or assembly is necessary, and the number of process steps
is significantly reduced, where the process fits ideally into the PCB fabrication process. The material
properties, the TPA processing of waveguides, and the integration concept will be discussed.
Recent experiments employing vertical-cavity surface-emitting lasers demonstrated data rates
exceeding 6 Gbit/s.