Spectrally-efficient 100 Gb/s transmission in next-generation optical access networks employing directly detected optical-OFDM

Forthcoming 100 Gb/s Ethernet (100 GbE) standard has targeted 100 Gb/s transmission over 10 km and 40 km of single mode fiber (SMF) using four channel (4 × 25 Gb/s) wavelength division multiplexed systems, which is neither cost effective nor spectrally efficient compared to a potential single channel system exploiting higher order modulation such as optical orthogonal frequency division multiplexing (O-OFDM). This paper investigates a single channel 100 Gb/s system based on directly detected 64-QAM O-OFDM that has an effective OFDM bandwidth of 24 GHz. It is found that the system can effectively enable error-free (at BER 10
³
without FEC) transmission of data at the desired distances of SMF without any in line amplification.