Optical Integrated Sensing and Communication: From Theory to Practice

Integrated sensing and communication (ISAC) technology enables simultaneous sensing and communication functions through shared hardware and resources tailored to specific applications. This technology reduces hardware costs and enhances system performance through synergistic interactions. While radio frequency-based ISAC (RF-ISAC) is well-studied, optical-based ISAC (O-ISAC) remains an emerging field. Compared with RF, light offers broader spectra, larger bandwidths, and flexible information transmission methods such as orbital angular momentum (OAM). Thus, O-ISAC research focuses on exploiting these unique optical advantages to significantly improve integrated system performance. This paper provides a comprehensive review of O-ISAC systems from three distinct perspectives: fundamental theory, system optimization design, and potential applications. By revisiting relevant optical theories and introducing novel insights, we propose a comprehensive theoretical framework grounded in light field theory to characterize and analyze the spatial distribution and propagation mechanisms of light. Leveraging this foundation, O-ISAC can be realized by coordinating multidimensional resources and harnessing light’s inherent structural properties. We then systematically examine critical performance metrics of integrated systems and propose an optimization framework that highlights essential technologies and corresponding evaluation criteria. Finally, the application of O-ISAC is illustrated with examples drawn from vehicular networks and hybrid optoelectronic base station architectures.