Demonstration of baud-rate-variable and channel-spacing-tunable demultiplexing of 10-40-Gbaud OFDM Subcarriers using a multi-tap optical DFT

We experimentally demonstrate a tunable and reconfigurable optical DFT to demodulate 10-40-Gbuad OFDM with 2/3/4 subcarriers at 20/40GHz frequency spacing. Average power penalty of ∼7 dB at BER of 10
⁻⁹
is achieved on the subchannels in the 4×20Gbit/s case, and ∼3 dB penalty is observed by using 50% guard time 4×10Gbit/s at 20G frequency spacing.