A fully integrated single-beam optical receiver is realised in a production 0.35 /spl mu/m CMOS process, which operates at 850 nm to 1 Gbit/s. The receiver integrates a photodiode, preamplifier, digital logic, and an off-chip driver. Pre-amplifier dissipation is <1.5 mW at 2.3 V, with an average optical power of -6.3 dBm required for 1 Gbit/s operation. Such a compact optical receiver may be of interest for short distance optical interconnects or local area networks.