Optical OFDM for the data center

We investigate the use of orthogonal frequency division multiplexing (OFDM) to increase the capacity of multimode fiber (MMF)-based optical interconnects for data center applications. This approach provides a solution to modulation bandwidth limitations of the lasers, and to the intermodal dispersion of the MMF which leads to frequency-dependent attenuation. Recent studies on adaptively modulated OFDM are reviewed, and new simulation results assessing the capacity of such links for lengths of up to 300 m are presented, assuming the use of 50/125 μm graded-index MMF at a wavelength of 850 nm. The use of coded OFDM as an approach to deal with intermodal dispersion is also discussed.