In the OPEN project the basic functionality of an all-optical OTDM-WDM interface, aiming at a capacity of 40 Gbit/s, has been analyzed and experimentally demonstrated. In a partitioned network structure, as envisaged in the networks studies arising from COST 239 project, the OTDM-WDM interface could provide an effective way of interconnecting two distant WDM networks by means of a OTDM trunk line by keeping the signal in the optical domain. Different applications can be foreseen, besides pure high capacity transmission: wavelength shuffle between networks and broadcasting, OTDM add-drop multiplexing.
The developed interface consists of two blocks :
- an OTDM to WDM converter, simultaneously performing demultiplexing from a high speed (40 Gbit/s) data stream into its tributaries at lower speed (10 Gbit/s), by assigning them a different output wavelength
- a WDM to OTDM converter, where many NRZ data streams at 10 Gbit/s at any wavelength are transformed into RZ pulses at a single wavelength, suitable for long distance transmission, and interleaved to get a very high speed (40 Gbit/s) data stream.