40-Gb/s TDM-PON Downstream Link With Low-Cost EML Transmitter and APD-Based Electrical Duobinary Receiver

We report a cost-effective 40-Gb/s time-division multiplexing passive optical network downstream link using three-level electrical duobinary modulation. The transmitter consists ofa compact electroabsorption-modulated laser module. The receiver contains an avalanche photodiode packaged with a transimpedance amplifier, with digitally adjustable gain and bandwidth, followed by a duobinary decoder. Real-time eye diagram and bit-error rate (BER) measurements were performed. At a preforward error correction BER of 10
^-3
, a power budget of 23.6 dB in back-to-back conditions is demonstrated. For a dispersion range of -215 to 128 ps/nm, the power penalty does not exceed 3 dB.