Christopher Janz

Transparent optical packet switching: the European ACTS KEOPS project approach

This paper reviews the work carried out under the European ACTS KEOPS (KEys to Optical Packet Switching) project, centering on the definition, development and assessment of optical packet switching and routing networks capable of providing transparency to the payload bit rate. The adopted approach uses optical packets of fixed duration with low bit rate headers to facilitate processing at the network/node interfaces. The paper concentrates on the networking concepts developed in the KEOPS project through a description of the implementation issues pertinent to optical packet switching nodes and network/node interfacing blocks, and consideration of the network functionalities provided within the optical packet layer. The implementation, from necessity, relies on advanced optoelectronic components specifically developed within the project, which are also briefly described.

Transparent optical packet switching: network architecture and demonstrators in the KEOPS project

This paper reviews the work carried out in the ACTS KEOPS (Keys to Optical Packet Switching) project, describing the results obtained to date. The main objective of the project is the definition, development, and assessment of optical packet switching and routing networks, capable of providing transparency to the payload bit rate, using optical packets of fixed duration and low bit rate headers in order to enable easier processing at the network/node interfaces. The feasibility of the KEOPS concept is assessed by modeling, laboratory experiments, and testbed implementation of optical packet switching nodes and network/node interfacing blocks, including a fully equipped demonstrator. The demonstration relies on advanced optoelectronic components, developed within the project, which are described.

Physical and logical validation of a network based on all-optical packet switching systems

The large growth of telecommunication traffic demand generated by multiple new applications and expected to last at least for the next decade will force telecom operators to consider offering more flexible transport services. All-optical packet switching is a powerful technique to provide this flexibility and to support in a cost-efficient way a wide range of bandwidth consuming applications. After a very brief introduction about the packet-switched network architecture studied in the framework of the ACTS KEOPS project, we describe the structure of the packet-switching node we have defined. We then move into physical and logical analysis of the network including more than 40 network sections based on 160 Gb/s throughput optical packet switching nodes could operate error free. In addition, logical simulations have proved that such networks could provide a quality of service (packet loss rate and packet transfer delay per node) compatible with a large variety of service classes. Both results validate the feasibility of the network concept and pace the way toward a flexible network based on all-optical switching techniques.

All-optical 2R regeneration at 40 Gbit/s in an SOA-based Mach-Zehnder interferometer

All-optical 2R regeneration in an SOA-based Mach-Zehnder interferometer is demonstrated at 40 Gbit/s. The regenerative capabilities combined with an input power dynamic range of 16 dB demonstrate the feasibility of this technique at very high bit rates.

Experimental validation of an all-optical network based on 160 Gbit/s throughput packet switching nodes

We present for the first time a physical validation of an all-optical packet-switched network. More than 40 network sections, including 100 km of fibre and one optical packet switching node, have been cascaded with negligible sensitivity penalty at 10 Gbit/s.

Full validation of an optical 3R regenerator at 20 Gbit/s

An optical 3R regenerator combining semiconductor optical amplifier-based Mach Zehnder interferometers is assessed at 20 Gbit/s. Inserted in a recirculation loop including 110 mm of dispersion shifted fibre, more than 200 regenerators have been cascaded.

3R optical signal regeneration

In this chapter the different means for all-optical signal regeneration are outlined. 3R regeneration implies signal reshaping and retiming and is based on optical decision circuits and devices for optical clock extraction respectively. In what follows, it will become clear that most of the optical decision circuits are based on active interferometers while devices for clock recovery are generally self-pulsating laser diodes. Keywords: non-linear interferometers; clock extraction; signal degradation; optical decision circuit

All-active dual-order mode Mach-Zehnder wavelength converter for power-efficient, co-propagative operation

Power-efficient wavelength conversion in the co-propagative configuration, with high input signal rejection, is reported using a novel all-active dual-order mode Mach-Zehnder wavelength converter. A dual-order mode Mach-Zehnder wavelength converter has been realised for the first time using exclusively active waveguides. Such an all-active implementation is highly advantageous from a fabrication effort point of view. Almost penalty-free conversion was obtained at 2.5Gb/s in the co-propagative mode, with high input signal rejection.

Low-penalty 10 Gbit/s operation of polarization-insensitive Mach-Zehnder wavelength converters based on bulk-tensile active material

Summary form only given. Interferometric structures based on semiconductor optical amplifiers (SOAs) have emerged as promising candidates for all-optical wavelength conversion applications, because they can deliver strong extinction ratio enhancement for both wavelength down- and up-conversion. Here we believe we report the first demonstration of nearly penalty-free 10 Gbit/s wavelength conversion using all-active bulk-tensile Mach-Zehnder wavelength converters.

Performance and system margins at 10 Gbit/s of an optical repeater for long haul NRZ transmission

Performances in terms of minimum admissible signal-to-ASE ratio and power dynamic range and system margins of a semiconductor optical amplifier-based regenerator have been investigated at 10 Gbit/s with NRZ signals in long haul transmission experiments.