Fig. 1. Main approaches for multi-wavelength optical carrier generation. (a)(b) Optical frequency comb (OFC); (c) optoelectronic oscillator; (d) single-frequency laser array

Fig. 2. Illustration of principle of multi-wavelength optical carrier generation

Fig. 3. Schematic of simulated Brillouin scattering (SBS) dual-wavelength optical carrier generation system

Fig. 4. Frequency-stabilized low-noise optically generated terahertz carrier. (a) Experimental apparatus; (b) spectrum of optical carrier; (c) frequency spectrum of terahertz carrier

Fig. 5. Frequency stability and tunability of low-noise THz carrier, reproduced from Ref. [13]. (a) Output frequency scatter diagram; (b) Allen deviation; (c) output frequency under fine tuning

Fig. 6. Phase noise measurement of optically generated terahertz carrier. (a) Schematic of experimental apparatus; (b) measured phase noise curves

Fig. 7. Experimental setup for photonic terahertz wireless communication demonstration, reproduced from Ref.[17]

Fig. 8. Transmission performance comparison of photonic terahertz communication systems, reproduced from Ref. [17]. (a) Bit-error-rate (BER) comparison for two light sources under different baud rates; (b) constellation with electro-optic comb as light source; (c) constellation with SBS carriers as light source

Fig. 9. Multi-wavelength optical communication system with parameter sharing. (a) Schematic of experimental apparatus, where the inset is spectrum of dual SBS carriers; (b) spectrum of tri-wavelength SBS carriers; (c) phase compensation comparison of two communication channels; (d) bit-error-rate (BER) comparison for both channels under independent 　　and joint processing; (e) comparison of computation amount required by independent and joint processing