This paper describes a Wavelength- Division- Multiplexing (WDM) optical switching technique that achieves 5-Tb/s switch throughput. This technique is employed in our previously described OPTically Interconnected Distributed Multi-stage Tb/s-ATM switching Network Architecture, called OPTIMA-2. This is a scalable and non-blocking 3-stage switch employing optical WDM and dynamic bandwidth sharing. An inter-stage, cell-based WDM switch is fabricated in combination with field programmable gate arrays (FPGAs) and 2.5-Gb/s 8-wavelength optical interconnection modules. Experimental results from a 5-Tb/s switching system are introduced.