Ghost diffraction in complex scattering media: Principles and applications

Ghost diffraction has been widely studied from quantum to classical to computational, and its applications in imaging and communication have been continuously presented. This review comprehensively analyzes ghost diffraction principles, focusing on communication and imaging applications in complex scattering media. This review reports the challenges in ghost communication and imaging when complex scattering media exist and describes promising approaches to overcoming the challenges. In terms of ghost communication in complex environments, the generation of information carriers using various methods is described, e.g., zero-frequency component replacement, untrained neural networks, and iterative algorithms, etc. The methods exhibit high robustness in high-fidelity data transmission, and physically secured communication can be realized. In terms of ghost imaging (GI) in complex environments, the enhancement of spatial resolution is described and discussed. The integration with correction approaches provides a promising direction to achieving high robustness in GI in complex environments. Orbital angular momentum transmission based on GI is discussed, and dual-modality approaches are illustrated for simultaneous implementations of free-space transmission and imaging. High-resolution microscopic imaging with single-pixel detection in complex media is also presented. With the introduction and comparison of the state of the art on ghost diffraction in complex media and its applications, this review would inspire future research in ghost diffraction and the exploration of new applications from quantum to classical to computational.