  We present the application of quantum key distribution technologies to
fiber-based broadband passive optical access networks. This application is
based on our 850 nm wavelength gigahertz clock-rate single-receiver system, is
compatible with existing telecommunications fiber and exploits a wavelength
band not currently utilized in access networks. The developed quantum key
distribution networks are capable of transmitting over distances consistent
with the span of access links for metropolitan networks (10 km), at clock
frequencies ranging up to 3 GHz.
