Using a Si photonic integrated circuit and separate SiGe transimpedance amplifiers, we created a high-performance dual-polarization, dual-quadrature coherent receiver. It requires only 16.3-dB optical signal-to-noise ratio to receive a 112-Gb/s polarization-division-multiplexed quadrature phase-shift keying signal at a <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$10^{-3}\ \hbox{bit-error}\ \hbox{rate}$</tex></formula> . <?Pub _bookmark="" Command="[Quick Mark]"?>