Erni, Daniel; Lenz, Daniel; Lehky, Jan-Marc; Offrein, Bert Jan; Lamprecht, Tobias:

Upgrading multimode channels for multi-Tb/s/inch bandwidth densities in board-level optical interconnects

In: European Microwave Association Proceedings (EuMA Proceedings), Special Issue on Microwave Photonics, Jg. 3 (2007) ; Nr. 3, S. 222-228
Zeitschriftenaufsatz / Fach: Elektrotechnik
Abstract – To keep up with the increasing demand for data rate
in high-end servers, and especially in configurations encompassing
e.g. symmetric multi-processor (SMP) systems, I/O memories
and ultra-fast system bus links, board-level optical interconnects
have become increasingly important even for very short
link topologies “inside the box” being typically in the range
of 10 cm that may scale up to several meters. Merging optical
waveguide technology with state-of-the-art printed circuit board
(PCB) production is reliable only if the involved waveguide cross
sections are of considerably large extent, leading to a highly
overmoded optical transmission channel. As in mobile communications,
such “problematic” channels are prone to be exploited
by advanced transmission schemes based on multipleinput
multiple-output (MIMO) communications. We present the
idea of an optical MIMO channel by having more than one laser
source at the input and a detector array at the output.With proper
tailoring of the underlying mode group multiplexing mechanism,
aggregate data rates in the multiple 10 Gb/s range may be achievable
supporting bandwidth densities of 10 Tb/s/inch already with
present optical interconnect technologies.
Index Terms – Optical MIMO system (O-MIMO), Optical interconnects,
Optical backplane communications, Mode group multiplexing,
Multimode waveguides, Fast system models.