A transceiver on a CMOS chip including optical and optoelectronic devices, and electronic circuitry may be operable to communicate optical signals between the CMOS chip and optical fibers coupled to the CMOS chip via a semiconductor laser and one or more photodetectors. The optical and optoelectronic devices may include waveguides, modulators, multiplexers, switches, and couplers. The photodetector may be integrated in the CMOS chip. The photodetector and the semiconductor laser may be mounted on the CMOS chip. The optical signals may be communicated out of and in to a top surface of the CMOS chip. A transceiver on a CMOS chip including optical and optoelectronic devices, and electronic circuitry, may be operable to communicate optical signals between the CMOS chip and optical fibers coupled to the CMOS chip via grating couplers. The optical signals may be communicated out of and in to a top surface of the CMOS chip.