On-board Optical Fiber and Embedded Waveguide Interconnects

The relentless demand for more network bandwidth drives the need for new optical connectivity solutions. A particular bottleneck is in the data center electrical interconnection length between the front panel and integrated circuits (IC) in switches and servers. Novel technologies and processes are required because future fully integrated silicon photonic optical transceivers will be co-packaged with the IC to reduce this electrical interconnect distance sufficiently to maintain the fidelity of increasing higher speed signals. Innovative fiber-to-chip connectivity, advanced packaging substrates, and embedded optical waveguide solutions for onboard optical interconnects in next generations of telecom and datacenter equipment are described in this paper. A novel connector approach was developed that has the potential to meet all co-packaging requirements including solder reflow compatibility, de-mateability, low insertion loss and active aligned fiber attach. Also for this application, a glass-based photonic interposer can he a beneficial alternative to state-of-theart substrate materials like organic laminates because of excellent radio-frequency, optical, mechanical and thermal properties. In the long term, embedded glass waveguides can replace optical fibers for higher optical channel density and enable optical printed circuit hoards.