Essex Corp of Columbia, MD, USA and the University of Essex, UK have used hyperfine wavelength division multiplexing (WDM) technology in a test-bed to set a claimed world record of 1.2Tbit/s throughput over 3km of conventional graded-index multi-mode fibre.

A hyperfine WDM filter with 6.25GHz channel spacing transmitted OC-48 data with claimed good "eye" diagrams on 12 channels across each 100GHz band of a 40-channel AWG on the ITU grid. The device was also used at the launch end without adjacent channel interference.

Dr Stuart Walker of the University of Essex's Department of Electronic Systems says that the test highlights the effectiveness of dense WDM (DWDM) techniques in getting maximum capacity from legacy installed multi-mode fibre.

Essex Corp's CTO Terry Turpin adds that it demonstrates hyperfine WDM's ability to bring ultra-dense WDM to the large amount of legacy multi-mode fibre on government and commercial LANs and campus network.

"Today, carriers use single-mode fibre exclusively, although the ability of wavelength-per-user applications using low-cost and easy-to-work-with multi-mode fibre could be the catalyst for mass deployment of cost-effective FTTH applications."