Dispersion Compensating Fibre in an Optical Access Network : A Complete Component and System Characterisation

Abstract

These last years numerous experiments with Dispersion Compensating Fibres (DCF) have been carried out. These experiments have shown that the DCF’s are promising components to upgrade optical fibre links previously designed to work in the second window. A lot of these experiments are dedicated to high distance multi-gigabit links and the possible implementation of DCF in sub-marine systems^1,2,3,4,5. These are the reasons why we would like to propose to discuss the possible use of DCF so as to upgrade second window Optical Access Networks (OAN). First, we fully characterise a commercial DCF. We measure optogeometrical parameters such as Mode Field Diameter (MFD) or refractive index profile difference. We use a home made Transmitted Near Field technique⁶. From these measurements, we calculate that connection with connectors as well as fusion splices give losses higher than one dB⁷. We observe a lower loss value with an Optical Time Domain Reflectometer (OTDR) analysis⁸. In a second time, we characterise the DCF parameters such as length, attenuation8 and chromatic dispersion⁹. We get a Figure-Of-Merit (FOM) of about 204 ps/(nm.dB) ¹. From these results we estimate that our fibre could be used to compensate standard fibre lengths of about 5 km. Finally, we dynamically test the DCF associated with a Standard Single-mode Fibre (SSF) in a single link using a 1.55 μn Fabry-Perot laser modulated up to 500 Mbit/s. We observe a significant improvement of the transmission with the DCF. We apply the same set-up to a point-to-multipoint link by using a conventional splitter. In this case the compensation is also achieved with success. All these experimental results are compared to theoretical calculations.