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Within the STOLAS project, an orthogonal optical labeling scheme using Frequency Shift Keying modulation for the 155 Mbit/s label and intensity modulation for the 10 Gbit/s payload data is being explored. This scheme enables to improve the throughput of packet-switched networks by efficient label processing and all-optical routing of packet bursts. The paper will address the networking aspects of this novel labeling scheme, the key components for implementing it, some first experimental results, and the prospects for application in future high-capacity optical packet-switched networks.

We propose an Automatic Gain Control block for Optical Label-Switched networks. The system adapts the power level of the incoming FSK/IM signal for optimal wavelength conversion operation.

Assigning a wavelength label as well as a label in a DPSK modulation format orthogonal to the data payload significantly increases the forwarding and routing capabilities of optical packet routers in IP-over-WDM networks.

A novel two-level optical labeling method for highly efficient transport of IP packets through WDM networks is proposed. By assigning both a wavelength label and a label in DPSK or FSK format (orthogonal to the ASK format of the data payload), packets can be routed transparently through end-to-end optical paths. The design of a duallabel controlled optical router is presented, which features label swapping and multicasting. Key element is an optically integrated wavelength converter and phase modulator. This work is part of the new IST project STOLAS – Switching Technologies for Optically Labeled Signals.

A combination of flexible optical time division multiplexing and dense wavelength division multiplexing techniques is deployed for realising a reconfigurable multi-Tbit/s data transport network connecting over 13000 telescope antennas. Both short-range and long-range transport in the 1.3 µm and in the 1.5 µm wavelength range, respectively, are explored.

The current status of high speed 1300 nm optical transmission will be reviewed in this paper. In particular the activities within the collaborative ACTS Upgrade project will be presented comprising 10 Gbit/s field trials, an experimental 40 Gbit/s OTDM laboratory test bed and initial work on 40 Gbit/s WDM transmission.

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Using an 1309 nm RZ transmitter at 10 Gbit/s and a chain of semiconductor optical amplifiers a record high transmission capacity of 4200 Gbit-km/s has been established. RZ 10 Gbit/s transmission at 1309 nm over a 420 km standard single mode fibre link with lumped amplification is demonstrated. A total of 12 multiple quantum well optical amplifiers were used to compensate for the fibre losses.

We have compared the operation of semiconductor and fibre optical amplifiers for the 1300 nm optical window. The key paraIneters are considered and evaluated with regard to different amplifier applications in telecommunications systems. We have studied representative data of both amplifier types, i.e. characteristics of indium gallium arsenide strained quantum well laser amplifiers (QWLA's) and Pr3 +_ doped germanium gallium sulphide fibre aInplifiers. Concerning the QWLA's, use of both compressively and tensile strained quantum wells allow for a high polarisation insensitivity while maintaining a high gain. For these amplifiers experimental as well as modelling data are available. Looking at the fibre amplifiers, GeGa sulphide glass is a-promising host glass material for a state-of-the-art device due to its low phonon energy. Optical properties of bulk sulphide glass already allow for modelling of the fibre amplifier characteristics. In general, semiconductor and fibre amplifiers exhibit competitive performances in terms of gain, saturation power and polarisation insensitivity. In WDM and analogue CATV systems implementation of fibre amplifiers is expected to be more attractive than semiconductor amplifiers, mainly due to the low carrier lifetime (::::::200 ps) of the latter amplifier type. N evertheless, this application is still under investigation. On the other hand, the low carrier lifetime provides the opportunity of wavelength conversion within the semiconductor amplifier.