Full-polarization-compatible optical storage for arbitrary polarized modes

Efficient quantum storage for polarization-encoded information is essential for quantum communication and quantum computation. However, current high-efficiency quantum storage, particularly those based on electromagnetically induced transparency (EIT) protocol in atomic media, exhibit an inherent sensitivity for photonic polarization. This necessitates transforming the polarization encoding into path encoding, setting strict requirements for phase and alignment stability. In this work, we experimentally demonstrate an efficient and polarization-insensitive optical storage for arbitrary polarized modes into a cold 87Rb atomic ensemble with a path-separation-free architecture. We obtain a storage efficiency exceeding 50% for the arbitrary polarization mode, and the storage fidelity surpass 95%, which is far above the classical benchmark. The achieved full-polarization-compatible storage for arbitrary polarized modes promises significant advancements in quantum communication and networking. Quantum memory for polarization-encoded light is vital for quantum communication. The authors build a cold 87Rb memory that enables polarization-insensitive storage, achieving more than 50% efficiency and more than 95% fidelity for arbitrary polarization modes.