Platform for emergency optical networking applications

The Centre for Integrated Photonics (CIP) has announced a hybrid assembly technique that offers a very simple yet highly reliable method of integrating optical devices.

The field-proven technique eliminates the expense of actively aligning devices providing a cost-effective platform for creating the sophisticated building-blocks required for advanced optical networking.

"Hybrid integration is an optimal way forward for many of the optical functions needed in advanced optical networks, but most of the assembly techniques in mainstream use today rely on highly skilled labour and expensive equipment, and do not scale," says Graeme Maxwell, CIP's VP of Hybrid Research and Development.

"Our technique requires just passive assembly, yet provides very low insertion losses " making it possible to create single-module solutions for applications such as packet switches and signal regenerators."

The technique integrates by means of plugging silicon daughterboards carrying individual optical components into a planar silica motherboard " each having precision-machined mating faces. The components themselves also employ simple interface modifications " namely mode expansion, and features to support precision cleaving.

The result turns hybrid photonic integration into a similar form of process to that used for assembling electronic PCBs " with the planar silica motherboard providing the equivalent of printed wiring.

The assembly techniques has been developed and refined over a timespan of about 10 years, and has been highly optimised for low interface losses and ease of assembly, and does not involve any complex processing or etching. The technique is also highly scalable, and applies equally well to two devices or a large subsystems integrating many component elements.

CIP has manufactured numerous devices using the technique, such as its 2R regenerator " a recently announced commercial device that is attracting a lot of interest from optical network developers. On this example of its hybrid integration, the component integrates a planar silica Mach-Zehnder interferometer (MZI) and a monolithic quad semiconductor optical amplifier (SOA) array to create a dual-channel 2R regenerator with just a 1 dB loss at daughterboard/motherboard interfaces.

"We believe this hybrid integration technique provides the performance, reliability and economy to address many of the sophisticated component functions necessary for advanced optical switched fabrics," adds Maxwell.

"Among the potential applications are reconfigurable add-drop multi-plexers, 2R and 3R signal regenerators, high-speed interconnect, packet switches, WDM PON devices and optical buffer memories. In each of these cases I expect our platform approach to offer considerable cost reduction and performance advantages over current component solutions and integration methods."