DOI: 10.1109/TMTT.2025.3532810   IEEEXplore: https://ieeexplore.ieee.org/document/10870472    

This invited review brings together the latest breakthroughs—from photonic front-end transceivers and optical resource multiplexing to integrated waveforms and adaptive ISAC base stations—showing how photonics could reshape the 6G landscape.

Compared with electronics, microwave photonics offers ultrabroad operating spectrum (from microwave into sub-THz), rich parallel optical resources (polarization-division and wavelength-division multiplexing), ultra-low fiber loss (~0.2 dB/km), and strong EMI immunity—key enablers for scalable ISAC.

Photonic frontend transceivers for 6G ISAC systems for real-time data sharing, user sensing and positioning, vehicle-to-everything communications and people-device collaboration, for example.

For ISAC technologies based on resource multiplexing, reviewed applications employed a variety of multiplexing techniques and signal generation methods to achieve data rates up to 251 Gbit/s, 0.25 to 750 cm sensing resolution with spectral efficiencies up to 6.24 bits/Hz. For ISAC technologies based on integrated waveform, reviewed applications employed OFDM-based, LFM-based, and spread-spectrum signal to achieve data rates up to 47.54 Gbit/s, 0.86 to 30 cm sensing resolution with spectral efficiencies up to 4 bits/Hz. For ISAC adaptive base stations, reviewed works describe how to jointly utilizing sensing and communication. Adaptively adjust parameters to flexibly assign resources to communication and sensing function.