On-Chip Polarization- and Frequency-Division Demultiplexing for Multidimensional Terahertz Communication

Integrated terahertz (THz) technology is of great significance for driving high-speed communication, sensing, and imaging with its advantages of miniaturization, low cost, and high efficiency. Recent research has focused on highly-efficient transmitters and ultrafast detectors, as well as exploring new devices for coupling, transmission, and polarization control. However, multidimensional on-chip multiplexing and demultiplexing techniques in the THz region still remains unexplored, due to the lack of multifunctional integrated components and systems. Here, a novel silicon-based integrated multidimensional THz (de)multiplexer for high-capacity communication is proposed and demonstrated based on ring resonators and polarization beam splitter-rotators, which simultaneously enable the manipulation of THz polarization and frequency. Furthermore, a THz communication system operating in the 380 GHz band is experimentally demonstrated. By using on-chip polarization- and frequency-division multiplexing techniques, an aggregate data rate of 8 Gbit s⁻¹ is successfully achieved with quadrature phase-shift keying modulation scheme. This work provides a spectrally efficient way for accelerating the development of on-chip THz technologies and the application in future large-volume communications.