Fast Optical Signal Processing in Optical Transmission was one of the highlights at this years IEEE LEOS Summer Topical Meetings. It is an exciting field that becomes more and more interesting as the progress in component technology enables higher efficiency and switching speed. To avoid any misunderstandings, focus is not on massive or complex signal processing as would be required in optical computing. On the contrary focus is on simple optical processing elements that can play a role in future high capacity transmission systems in overcoming speed limitations of electronics and at the same time avoid tedious opto-electronic conversions. Simple optical signal processing will also play a role in optical switching nodes that must handle huge amounts of traffic. In the nodes we need all-optical functions for packet routing, 3R regeneration, buffering, etc. Again, it must be emphasised that it is a main task to understand the role sharing between electronic and optical signal processing technologies.

Placed in the wonderful settings of Mont Tremblant in Canada the meeting with its mixture of invited and contributed papers from all over the world gave a very comprehensive coverage of the state of optical signal processing. Both the components and systems aspects were covered in the densely packed two and a half day program.

A number of papers covered the systems perspectives of signal processing in transparent optical networks, packet networks, OTDM packet networks as well as in OTDM systems generally. Besides a joint session with two of the other collocated topical meetings addressed all optical networking issues. The presentations served the very important task of giving a better understanding of where all-optical signal processing has a role to play.

On the components and sub-unit level a number of contributions focused on signal processing using semiconductor optical amplifiers (SOA’s) in interferometric structures. They operate at data rates exceeding the capabilities of electronics and a number of presentations concentrated on achieving even higher switching speeds by optimising the operation of the structures and also by tailoring their material properties. Experiments at data rates higher than 300 Gbit/s were reported. A number of presentations showed how the components can be used for label swapping, header correlation and recognition, OTDM channel selection, bypass switching, all optical XOR, bit level synchronization and other important functionalities. All-optical clock recovery was also presented in a number of papers demonstrating the steady progress in the realization of all-optical clock recovery in TDM as well as Packet networks. Also units for duobinary transmission of optically waveform shaped pulses were reported. Moreover, one presentation gave state of the art of parametric optical amplifiers that is a field of increasing interest because of the emergence of new non-linear materials .

This LEOS Newsletter features extended versions of the invited conference papers. As you will see optical signal processing has come a long way. It is, however, also a field where there is still much exciting research to be done in developing new components and also new systems concepts. I am convinced that we will see more and more examples where it makes sense to implement optical processing units in future optical systems.