Entanglement Swapping Of Frequency-Uncorrelated Narrow-Band Entangled Photon Sources

In this thesis, we mainly discuss the experimental preparation of frequency-uncorrelated narrowband polarization-entangled photon sources and their appli-cations in quantum information.The preparation and storage of photonic entanglement are central to the achievement of scalable linear optical quantum computation(LOQC), long dis-tance quantum communication and large-scale quantum networks. Frequency-uncorrelated narrowband polarization-entangled photon sources were developed to solve this problem.First of all, we have generated frequency-uncorrelated narrowband polarization-entangled photon sources through cavity-enhanced sponteneous parametric down conversion(SPDC).Then, based on this work, we have realized storage of single photon of nar-rowband entanglement state, storage of biphoton entanglement state, quantum entanglement swapping of narrowband entangled states. These works provide ex-perimental evidence and necessary technical support for demonstration of quan-tum repeaters.At last, by exploring and developing time-resolved measurement and active feed forward, we have entangled two independent photons of different colors for the first time. This work provides a ubiquitous approach to solving the frequency-mismatch problem for the interconnection of dissimilar quantum systems, and thus may become an essential tool for future quantum networks.