The design, implementation and characterisation of an electro-optical
backplane and an active pluggable in-plane optical connector technology
is presented. The connection architecture adopted allows line cards to
be mated to and unmated from a passive electro-optical backplane with
embedded polymeric waveguides. The active connectors incorporate a
photonics interface operating at 850 nm and a mechanism to passively
align the interface to the optical waveguides embedded in the backplane.
A demonstration platform has been constructed to assess the viability of
embedded electro-optical backplane technology in dense data storage
systems. The demonstration platform includes four switch cards, which
connect both optically and electronically to the electro-optical backplane
in a chassis. These switch cards are controlled by a single board
computer across a Compact PCI bus on the backplane. The electrooptical
backplane is comprised of copper layers for power and low speed
bus communication and one polymeric optical layer, wherein waveguides
have been patterned by a direct laser writing scheme. The optical
waveguide design includes densely arrayed multimode waveguides with
a centre to centre pitch of 250μm between adjacent channels, multiple
cascaded waveguide bends, non-orthogonal crossovers and in-plane
connector interfaces. In addition, a novel passive alignment method
has been employed to simplify high precision assembly of the optical
receptacles on the backplane. The in-plane connector interface is based
on a two lens free space coupling solution, which reduces susceptibility
to contamination. Successful transfer of 10.3 Gb/s data along multiple
waveguides in the electro-optical backplane has been demonstrated and
characterised
