Demonstration of cost-effective photonic terahertz frequency-division multiplexing by ultra-fast wavelength tunable lasers

Abstract To meet the growing demand for data-intensive applications, it is essential to further enhance the capacity of terahertz (THz) wireless links. Frequency-division multiplexing (FDM), which enables the simultaneous transmission of multiple carriers, has emerged as a promising approach. However, existing THz-FDM methods typically rely on multiple electronic or photonic components, such as multiple lasers or optical frequency comb sources, which significantly increase system cost and hinder large-scale deployment. In this work, we propose a component-minimized photomixing architecture that employs a single ultra-fast wavelength tunable laser together with a fixed-wavelength laser, combined with a low-cost fiber-delay self-multiplexer for multi-carrier generation. Using this scheme, we successfully generate three THz carriers at 230.0, 270.8, and 310.4 GHz simultaneously. The proposed approach reduces the hardware complexity and cost of THz-FDM while tripling the achievable data rate, thereby providing a practical and scalable pathway toward high-capacity THz wireless communication systems.