1East China Normal University, State Key Laboratory of Precision Spectroscopy, Joint Institute of Advanced Science and Technology, School of Physics and Electronic Science, Shanghai, China
2CAS Center for Excellence in Ultra-intense Laser Science, Shanghai, China
3Shanxi University, Collaborative Innovation Center of Extreme Optics, Taiyuan, China
Quantum state sharing, an important protocol in quantum information, can enable secure state distribution and reconstruction when part of the information is lost. In (k, n) threshold quantum state sharing, the secret state is encoded into n shares and then distributed to n players. The secret state can be reconstructed by any k players (k > n / 2), while the rest of the players get nothing. In the continuous variable regime, the implementation of quantum state sharing needs the feedforward technique, which involves optic-electro and electro-optic conversions. These conversions limit the bandwidth of the quantum state sharing. Here, to avoid the optic-electro and electro-optic conversions, we experimentally demonstrate (2, 3) threshold deterministic all-optical quantum state sharing. A low-noise phase-insensitive amplifier based on the four-wave mixing process is utilized to replace the feedforward technique. We experimentally demonstrate that any two of three players can cooperate to implement the reconstruction of the secret state, while the rest of the players cannot get any information. Our results provide an all-optical platform to implement arbitrary (k, n) threshold deterministic all-optical quantum state sharing and pave the way to construct the all-optical broadband quantum network.