10 Gb/s Duobinary Receiver with a Record Sensitivity of 88 Photons per Bit

We demonstrate a novel receiver concept for duobinary signals that allows data recovery with a sensitivity of -39.5dBm (88 Photons/bit) launch power at BER-1.10 sup -9. Oversampling together with a maximum likelihood sampling phase estimation results in superior back-to-back performance without lowering the large chromatic dispersion tolerance of duobinary signaling.