Fiber-Optic THz Wireless Uplink with Remote Down-Conversion by Optical Carriers Transmitted from Central Office

Terahertz (THz) frequency bands are promising for high-speed wireless communications because of the wide unused spectrum. However, the limited THz coverage due to high transmission loss requires a wide distribution of small cells. Seamless conversion between broadband optical and wireless networks can address the need for cost-effective cells. Here, we propose and demonstrate a remote down-conversion scheme for a fiber-optic THz wireless uplink. A photomixer reuses optically transmitted tones to generate a high-frequency local oscillator signal for the remote down-conversion, reducing the need for high-frequency and costly components. Single-channel 45-Gbps data transmission over a 5-km fiber and a 1-m THz wireless link is achieved based on soft-decision forward error correction thresholds (2 × 10-2).