ABSTRACT
This chapter deals with optical transmission employing orthogonal frequency division multiplexing (OFDM) techniques in which several subcarriers are employed to carry partitioned data for transmission over the fiber channel. The channels are frequency multiplexed and orthogonal. The orthogonality comes easily from the generation of the fast Fourier transform (FFT) and inverse fast Fourier transform of the data sequence in the electronic domain. These subcarriers in the baseband are then modulating the optical carrier under some modulation formats that are most appropriate for optical fiber channels. The narrow band of the data of subchannels ensure the low broadening of the pulses, hence combating effectively the impairments expected from the fiber. This advanced modulation and optical transmission technique (oOFDM) is emerging over the last few years as one of the most potential candidates for long-haul optically amplified communication systems and networks and for low-cost metro and access optical networks.
