Fifty-five km reach,bidirectional, 400 Gb/s(40×10 Gb/s), channel-reuse DWDM–PON employing a self-wavelength managed tunable laser

We experimentally demonstrate a channel-reuse bidirectional 10 Gb∕s∕λ long-reach dense wavelength-division multiplexing passive optical network(DWDM-PON) and an optical beat-noise-based automatic wavelength control method for a tunable laser used in a colorless optical network unit(where λ· wavelength). A55 km, bidirectional, 400 Gb/s(40 × 10 Gb∕s) capacity channel-reuse transmission with 100 GHz channel spacing is achieved. The transmission performance is also measured with different optical signal to Rayleigh backscattering noise ratios and different central wavelength shifts between upstream and downstream in the channel-reuse system.