Analog phase-sensitive time-reversal of optically carried radiofrequency signals

Achieving low-latency time-reversal of broadband radiofrequency signals is crucial for reliable communications in dynamic, uncontrolled environments. However, existing approaches are either digitally assisted-making broadband extension challenging-or limited to amplitude modulation. In this work, we report the very first, to our knowledge, experimental realization of a fully analog, phase-preserving time-reversal architecture for optically carried radiofrequency signals. The method exploits the exceptional coherence properties of rare-earth ion-doped materials and leverages the well-established photon echo mechanism, widely used in quantum technologies. While our demonstration is conducted with a modest bandwidth, we identify the fundamental cause of this limitation and propose solutions for future scalability.