Affiliation:
1. NTT Device Technology Laboratories
2. National Institute of Information and Communications Technology (NICT)
3. Kobe University
4. NTT Corporation
5. The University of Tokyo
Abstract
Quantum frequency conversion (QFC), which involves the exchange of frequency modes of photons, is a prerequisite for quantum interconnects among various quantum systems, primarily those based on telecom photonic network infrastructures. Compact and fiber-closed QFC modules are in high demand for such applications. In this paper, we report such a QFC module based on a fiber-coupled 4-port frequency converter with a periodically poled lithium niobate (PPLN) waveguide. The demonstrated QFC shifted the wavelength of a single photon from 780 to 1541 nm. The single photon was prepared via spontaneous parametric down-conversion (SPDC) with heralding photon detection, for which the cross-correlation function was 40.45 ± 0.09. The observed cross-correlation function of the photon pairs had a nonclassical value of 13.7 ± 0.4 after QFC at the maximum device efficiency of 0.73, which preserved the quantum statistical property. Such an efficient QFC module is useful for interfacing atomic systems and fiber-optic communication.
Funder
Program for Leading Graduate Schools: Interactive Materials Science Cadet Program
Japan Society for the Promotion of Science
Core research for Evolutional Science and Technology
Moonshot Research and Development Program
Subject
Atomic and Molecular Physics, and Optics