Dual Polarization Coherent Optical Spectrally Efficient Frequency Division Multiplexing

A new optical spectrally efficient frequency division multiplexing technique, utilizing coherent detection and polarization division multiplexing, is proposed and demonstrated. The proposed system uses non-orthogonal and overlapping subcarriers to provide a significant reduction in both the electrical and optical bandwidth of up to 33%, relative to dual polarization orthogonal frequency division multiplexing (DP-OFDM), with an implementation penalty <;3.2 dB. After transmission over 80 km of single mode fiber, it is shown that quadrature phase shift keying-based DP coherent optical spectrally efficient frequency division multiplexing, achieves a 2-dB gain in optical signal-to-noise ratio performance relative to eight-quadrature amplitude modulation-based DP-OFDM, which has approximately the same spectral efficiency.