Transponders for real time DWDM networks

Dense wavelength division multiplexing (DWDM) is a technology that assigns to the users of an optical network specific wavelengths or "colors" and mixes them in a single strand of fiber. Heterogeneous data is transmitted simultaneously across lanes of light, which are demuxed at the receiving end and delivered to the clients. Instead of deploying more fibers or increasing the data transfer rate, the bandwidth of an optical link can scale by adding more wavelengths to the system. DWDM has been pioneered for applications in long-haul telecom networks, requiring bulky, sophisticated and custom instrumentations. Nowadays, most of the main components are available off-the-shelf as compact and reliable devices, making it possible to use this technology in real-time environments like data acquisition systems for high energy physics experiments. However, interfacing to DWDM components faces up to complex timing issues, protocol options and a brave new blend of optics and electronics. In this paper we present our tests of the AGERE\´S Translight CA16, a DWDM transponder capable of full-duplex optical operations at 2.48 Gbit/s (OC-48). In order to evaluate different design strategies, we have interfaced the transponder to a parallel bit error rate tester. The results are discussed In the view of a future integration of the transponder with an FPGA-based controller aimed at real-time applications.