HIGH-BANDWIDTH OEIC RECEIVERS USING HETEROJUNCTION BIPOLAR-TRANSISTORS - DESIGN AND DEMONSTRATION

The design, fabrication, and performance of the highest speed optoelec tronic integrated circuit (OEIC) receivers reported to date is present ed. These consist of PIN detectors and AlGaAs/GaAs HBT transistors fab ricated on the same GaAs substrate. The p-i-n detectors are made from the same base and collector epitaxial layers as used for the HBT trans istors and are completely compatible with our usual transistor fabrica tion process; no process alteration was required. We report 20-mum det ectors with 35.6% quantum efficiency, 40 nA dark current at -3 V bias, and bandwidth in excess of 17 GHz. These detectors are used to produc e two OEIC receivers, one with a bandwidth of 6.7 GHz and an equivalen t input noise current of 4.3 pA/Hz1/2 and another with a bandwidth of 13 GHz and an equivalent input noise current of 10 pA/Hz1/2. The perfo rmance of a variety of circuit topologies is compared and the effect o f different epitaxial layer structures on OEIC performance is investig ated.