PRACTICAL IMPLEMENTATION OF A HIGHLY SENSITIVE RECEIVER USING AN ERBIUM-DOPED FIBER PREAMPLIFIER

We demonstrate a practical erbium-doped fiber preamplified direct detection receiver, with which we achieve receive input sensitivities of -46.5 dBm at 622 Mb/s and -40.7 dBm at 2.3 Gb/s. There is no penalty from the transmission fiber Rayleigh backscattering. The bit error ratio measurements with 2(23) - 1 NRZ PRBS show highly stable characteristics with no apparent error floor, owing to the polarization insensitivity of the preamplifier and to an active locking of the receiver optical filter. We show the tradeoff between preamplifier and avalanche gain, and we measure the influence of optical filter bandwidth and decision threshold setting.