Fig. 1. Schematic diagram of photonics-assisted terahertz wireless communication system

Fig. 2. THz signal with multi-modulation format generation scheme based on electro-optical modulation

Fig. 3. Several new high-speed integrated electro-optical modulators. (a) Integrated lithium niobate electro-optic modulator^[13];(b) Hybrid silicon and lithium niobate Mach⁃Zehnder modulators^[14]; (c) U-shaped silicon photonics carrier depletion modulator^[15]; (d) Silicon-polymer hybrid modulator^[16]; (e) Ultra-compact silicon-electronic plasmonic high-speed modulator ^[17]

Fig. 4. Photonics-assisted THz heterodyne receiving technology. (a) Mixing based on UTC-PD^[18]; (b) Mixing based on photoconductor^[20]; (c) Electro-optical modulation based on POH modulator^[23]

Fig. 5. Typical experimental results of terahertz wireless communication system based on optical wavelength division multiplexing technology^[24]

Fig. 6. W-band wireless signal transmission system based on PDM, APM and MIMO

Fig. 7. Wireless signal transmission system based on WDM, PDM, APM and MIMO ^[36]

Fig. 8. Probability distribution diagram of signal after probability constellation shaping ^[39]

Table 1. Performance comparison of several new high-speed integrated electro-optical modulators