A silicon photonics integration circuit includes a silicon substrate member; a RX sub-circuit formed in the silicon substrate member including multiple RX-input ports each having a mode size converter configured to receive an incoming light signal into one of multiple waveguides and multiple RX photo detectors coupled respectively to the multiple waveguides; and a TX sub-circuit formed in the silicon substrate member including one or more TX-input ports each having a mode size converter coupled to a first TX photo detector into one input waveguide, one or more 1×2 directional couplers each coupled between the input waveguide and two mod-input waveguides, multiple modulators coupled between respective multiple mod-input waveguides and multiple mod-output waveguides each being coupled to a second TX photo detector into one of multiple output waveguides, and multiple TX-output ports each having a mode size converter coupled to respective one of the multiple output waveguides.