Experimental implementation of time reversal in an optical domain

Time reversal has enabled many fundamental breakthroughs through the exquisite control over the complex systems. More recently, time reversal is predicted to be capable of enhancing the quantum sensing in unprecedented ways. Here, we report the experimental demonstration of time reversal based on a unitary and orthogonal squeezing interaction in an optical domain. Two cascaded degenerate optical parametric amplifiers are used to judiciously achieve a time reversal protocol. Finally, the concept of high-fidelity time reversal is demonstrated in the optical domain, offering remarkable opportunities for investigating many-body simulation and achieving quantum-enhanced sensing.