Using higher-order passbands of multimode fibre for subcarrier multiplexing

The frequency response of multimode optical fibre (MMF) shows the existence of passbands in the higher frequency region above the -3dB baseband. By Subcarrier Multiplexing, these passbands can be used to accommodate a number of transmission channels for different services. In this way various groups of services may be integrated in a single MMF-based in-building or short-reach access infrastructure. In this paper, the power flow equation is solved numerically to investigate the passband response of MMF. The influence of modal delay, modal attenuation, mode coupling and launching conditions is studied. Results show large differences between overfilled launching and selective excitation launching.