The “Gigabit access passive optical network using wavelength division multiplexing” project aims to implement 64-Gb/s data transmission over 20-km single-mode fiber. Per-user symmetric data rates of 1-Gb/s will be achieved using wavelength division multiplexing passive optical network (WDM-PON) architecture with a 1:64 user split per PON segment. Enabling technologies being developed within the scope of the project include tunable transceivers and athermal 50-GHz array waveguide grating multiplexer devices. The future-proof WDM architecture will enable convergence triple-play (telephony, TV, and broadband internet) service over existing optical infrastructure, and also facilitate cost-effective dense wavelength division multiplexing for metro aggregation and mobile backhaul networks.