Demonstration of 400 Gbit/s/λ wireless transmission for a photonic-assisted SISO integration system at 220 GHz

We experimentally demonstrate a dual-polarized, single-input single-output (SISO) photonic-electronic integrated system, achieving a single-wavelength data rate of 400 Gbit/s at 220 GHz. This system is based on a self-developed IQ mixer, orthomode transducers (OMTs), and a dual-polarized multiplexing antenna (DPMA). The IQ mixer front-end exhibits a conversion loss of over 14 dB within a 30 GHz bandwidth, and cross talk between IQ channels is better than 15 dB for most frequency points. The OMT achieves a polarization isolation of over 30 dB and an insertion loss (IL) of less than 3 dB across the entire WR-4 band (170–260 GHz). The DPMA operates in the WR-4 band, with measured in-band return loss characteristics better than 15 dB. The 50 GBaud DP-16QAM modulation is successfully transmitted over a 20 km SSMF and a 1 m wireless link. Additionally, a 125 Gbit/s real-time transparent fiber-THz-fiber SISO transmission system is demonstrated, marking a significant advancement in the development of large-bandwidth, high-speed 6G photonic-electronic systems.