A Silicon Differential Receiver With Zero-Biased Balanced Detection for Access Networks

We present an optimized differential receiver in silicon with a minimized footprint and balanced zero-biased Ge photodiodes. The receiver integrates a delay-line with a 2×4 multimode interferometer 90° hybrid and two balanced photodiodes for differential quadrature phase-shift keying demodulation. Two receivers are tested, for 10 and 20 Gb/s operation, and well opened eye-diagrams and symbol constellations are obtained with error vector magnitude values as low as 12.5% and 19.57%, respectively. The results confirm the potential of integrated silicon receivers to become key building blocks for future passive optical access networks based on advanced modulation formats.