Polatis unveils port-reconfigurable all-optical switch

All-optical switch developer Polatis Ltd. has unveiled a 192-port completely reconfigurable optical switch that provides non-blocking connectivity between any pair of fiber ports with typically just 1 dB of path loss.

Conventional all-optical switches are dual-sided, making connections between a group of committed input ports on one side and a group of output ports on the other. Customers have been asking for flexible "any-to-any port" configurations to enable better network performance and more efficient use of capacity, the vendor says.

The 192-fiber customer-configurable (192xCC) single-sided optical switch comprises fiber ports that are uncommitted to input or output groups, which allows users the flexibility to make connections between any of the 192 fibers – a unique feature in the industry, according to Polatis. Without rigidly-defined input and output ports, the same optical switch module can be used for any combination of symmetric (NxN) and asymmetric (NxM) switch configurations.

UPDATE: Internally, the switch now contains a mirror. Previously, light coming into the switch via an input fiber passed through a collimator lens that could be tilted to point the beam of light at any of the output ports. By inserting a mirror half-way along the beam path, light can be reflected back to any of the input ports – so the distinction between input and output ports disappears.

UPDATE: The downside to the added flexibility is that the total number of fiber ports is halved. Steering beams of light with high accuracy is more difficult over wider angles, and as a result it becomes more challenging to build larger switches, sources at Polatis say. The largest switch the company offers has twice as many ports: 192x192. Most applications don’t require super-high port counts, however.

"The combination of software control and any-to-any port connectivity brings a new level of flexibility and choice to our customers for optimizing their fiber assets," said Gerald Wesel, CEO of Polatis. "The 192xCC reconfigurable optical switch provides full fiber connectivity without affecting system budgets, opening up new possibilities in data center and telecom networks for optical layer provisioning, protection, monitoring and test."

Research and education networks are interested in possibilities enabled by the properties of such a switch, especially in combination with software-defined networking (SDN). Earlier this year Polatis introduced support for SDN through an embedded OpenFlow agent, together with plug-in support for the OpenDaylight SDN controller, developed in collaboration with the University of Bristol (see "Polatis to demo SDN-enabled optical circuit switching at ECOC 2013").

"A 192-port single sided optical switch, with any port-to-any port connectivity, is a very versatile building block that increases the flexibility and graceful scalability of the overall metro node design in next-generation software-defined optical networks. These low-loss optical switches can be used in a multi-stage optical circuit switched layer to reduce costs and increase the scalability of future network core nodes," said Prof David Payne of Trinity College Dublin and coordinator for the European Framework 7 collaborative project DISCUS.

In other news, Polatis reports that it will provide optical switches for Aurora2, a next-generation dark fiber network that provides direct access at the optical layer to users developing new technologies and services for future applications of the Internet. The network is funded by UK Engineering and Physical Science Research Council (EPSRC) and the Higher Education Funding Council for England (HEFCE), through the Joint Academic Network, Janet. Aurora 2 is managed by a consortium led by University College London (UCL) with the Universities of Bristol, Cambridge and Southampton. Eleven Polatis optical switches will be deployed at nodes across the 800-km Aurora2 network to enable researchers to reconfigure the infrastructure on demand.

The 192xCC is the latest addition to the Polatis series 6000 family of optical switches, which are built using Polatis DirectLight beam steering technology. This enables fully transparent, low-loss connections entirely independent of the color, direction, power level or traffic protocol on the fiber.

For more information on optical switches and suppliers, visit the Lightwave Buyer’s Guide.