Overcoming the modal bandwidth limitation of multimode fibre by using passband modulation

It is demonstrated that the bandwidth limitation of multimode fibre links arising from modal dispersion can be overcome by using passband modulation in the frequency range beyond the 3dB bandwidth. Transmission of 1.25GBit/s over 500m of near-worst case 62.5μm multimode fibre is achieved using two subcarrier multiplexed channels at the 850nm wavelength. In contrast the conventional baseband transmission distance is limited to 300m at this data rate.