PhoxTroT developing new optical interconnects

22 Jan 2013

Fraunhofer-led consortium seeks a generic building block to extend performance and consume less energy.

A four-year research project, backed by the European Union and led by the Fraunhofer Institute for Reliability and Microintegration (IZM), intends to develop new optical interconnect components that tackle the growing costs and energy consumption of modern data centers.

Christened PhoxTroT, the project kicked off in October 2012. Eighteen partner companies and scientific centers are currently involved, and the EU is providing €9 million funding.

According to the project description, the primary aim is the deployment of a generic "building block" component that can be used for a broad range of applications, extending performance beyond the Tb/s regime and reducing energy consumption by more than 50 percent.

Other specific goals in the PhoxTroT work program include development of a unified integration and packaging methodology for board-adaptable 3D SiP transceiver and router optochip fabrication; and deployment of a new class of high-performance intra-chip through-silicon via (TSVs).

"The novelty of the PhoxTroT project is that we are now researching the synergies between the various technology components and are combining them with each other in a new research plan based on the mix-and-match principle," said project coordinator Tolga Tekin from Fraunhofer IZM. "By the end of the project, entirely new technologies are expected to emerge that can guarantee a photonic data connection that remains constant across hundreds of kilometers."

The partners are developing three prototypes for various hierarchy levels, intended to demonstrate optical transmission on an individual printed circuit board, as well as on a board-to-board and rack-to-rack level. Combining these interfaces should make it possible to bridge longer distances than is currently feasible.

A further step will be the engineering of single-mode solutions that integrate a number of optical chips onto a circuit board, allowing for signal transmission via one optical path.

Bringing Europe to the forefront
The broader goal is to bring European research and industry to the forefront of the optical interconnect field, through road mapping, dissemination and training activities, and strengthening its collaborative framework.

"The greatest challenge is coordinating partners from a wide range of disciplines," commented Tekin. "On the one hand, there are the technology experts; and on the other hand, the systems experts. We have to bring them all to one table, establish an understanding between them and guide the communications into the right channels."

In addition to Fraunhofer IZM, PhoxTroT partners include Fraunhofer Heinrich-Hertz-Institut; diode-developers Vertilas; IMEC; and Karlsruhe Institute of Technology (KIT).

A team at KIT recently demonstrated a novel optical connection between semiconductor chips, referred to as photonic wire bonding, in which a femtosecond laser writes the free-form waveguide structure directly into a polymer located on the surface of the chip.