LED-array based optical interconnects for chip-to-chip communications with integrated CMOS drivers, detectors, and circuitry

A direct optical interface on ICs has the potential to ease the bandwidth bottlenecks in transferring data between advanced ICs. We demonstrate high speed microLEDs transferred onto silicon CMOS circuitry together with the integrated drivers for the LEDs to send data from the IC. On the receive side of the same IC, we demonstrate integrated CMOS detectors with trans-impedance and limiting amplifiers. These chips are shown to operate at Gb/s speeds and can be interfaced with multicore fibers to make simple low-cost data-paths between standard silicon ASICs. Compared to SERDES based interfaces where only a few lanes are run at very high speeds, these wide parallel optical interfaces can be considerably lower power and offer much higher overall bandwidth and bandwidth density. We demonstrate these links using 130nm CMOS process on SOI substrates, with <2pJ per bit and show their superior performance compared to FP lasers in terms of BER and mode partition noise.