High-Quality Fiber-Based Heralded Single-Photon Source at 1.5 µm

A high-quality heralded single-photon source (HSPS) at 1.5 µm is experimentally demonstrated based on spontaneous four wave−mixing in a piece of dispersion-shifted fiber cooled by liquid nitrogen. To improve the up-limit of the preparation efficiency of the HSPS, commercial dense wavelength-division multiplexing components are used to reduce the loss of the filtering and splitting system between the fiber and the single-photon detectors. As a result, a preparation efficiency of 80% is realized under a g(0)⁽²⁾ of 0.06 in our HSPS experimental system, which is the best performance for the fiber−based HSPS at 1.5 µm reported so far.