20 Gbit/s wireless bridge at 220 GHz connecting two fiber-optic links

The feasibility of a wireless link at 220 GHz based on electronic upconversion and downconversion is demonstrated, connecting two optical links at data rates of up to 20 Gbit/s. We use either non-return-to-zero on-off keying with data rates up to 20 Gbit/s or electrical orthogonal frequency division multiplexing with data rates up to 9 Gbit/s. The wireless bridge connects the gateways of two spatially separated fiber sections, each with a length of up to 20 km.