Metasurfaces Enable Quantum Holograms with Entangled Photons

Researchers in Hong Kong and the UK have achieved a breakthrough in quantum physics by creating quantum holograms using metasurfaces. Published in Advanced Photonics on March 11, 2025, the study details how they manipulated entangled photons to encode intricate information with unprecedented precision. This method leverages metasurfaces, ultrathin optical devices, to control light and enhance the production of entangled photons. The team successfully created four holographic letters ("H," "V," "D," and "A") entangled with the polarization of paired photons. By adjusting polarizer orientations, they could selectively erase specific letters, demonstrating precise control over the holographic information. This innovation has potential applications in quantum communication, offering a secure way to communicate by encoding information in both the letters and polarization states. The technology also holds promise for anti-counterfeiting measures, as the intricate relationship between the letters, polarization states, and phase profile makes replication extremely challenging. The researchers believe that metasurfaces can significantly reduce the size of quantum optical systems, making this technology much more practical for everyday use.