Efficient polarization-entangled state compensation in quantum entanglement distribution
Xiaoyan Zhou, Hao Qin, Bo Li, Yuhuai Li, Sheng‐Kai Liao, Yuan Wen Cao, Juan Yin · Optics Express · 2025
The polarization states of the photons will be changed when distributing polarization-entangled photon pairs through their independent optical channels, whether satellite-based free-space or fiber-based links. Thus, it is essential to reconstruct the initial polarization-entangled state between their receiving ends. Here, we present an efficient compensation method based on coincidence measurements of entangled photons to restore the entanglement state. A unitary polarization transformation performed on a single optical link is sufficient using our method. Furthermore, we experiment to demonstrate the feasibility of this method by implementing the transformation with a set of three waveplates and employing one-step feedback. This study provides an efficient compensation technology for preserving the polarization-entangled state, which can be directly applied to applications involving quantum entanglement distribution.