An optoelectronic integrated circuit (OEIC) having an optical core coupled to first and second interface circuits. The first interface circuit is adapted to convert an electrical input signal into an optical signal; the optical core is adapted to process the optical signal in the optical domain; and the second interface circuit is adapted to convert the processed optical signal into an electrical output signal. In one embodiment, an OEIC of the invention is fabricated using a single wafer, has only electrical inputs/outputs, does not have any external optical interfaces, and is not adapted to receive any external optical signals. Advantageously, due to the signal processing being in the optical domain, a circuit of the invention carries out its functionality, with little or no performance degradation, over a relatively wide frequency range. In addition, this circuit has a relatively small size and can be relatively inexpensive.