Dynamics and fidelity of entanglement of photons coupled to optical fibers and waveguides

Han Chuen Lim, Akio Yoshizawa, Hidemi Tsuchida +1 more

We report the first experimental demonstration of wavelength-multiplexed entanglement distribution over optical fiber. Forty-four channels of polarization-entangled photon-pairs were produced from a single pulse-pumped, short periodically-poled lithium niobate waveguide and distributed over 10 km of dispersion-shifted optical fiber. Entanglement fidelities of the distributed photon-pairs exceeded 0.86 for all selected channels.

Andrei Yu. Khrennikov, B. Nilsson, Sven Nordebo +1 more

Lee C. Oesterling, Fernando Monteiro, Sean Krupa +7 more

To support quantum technologies that require entangled photon pairs and/or heralded photons for operation, a photon pair source was developed that uses periodically poled lithium niobate (PPLN) waveguides that are coupled to optical fibers. Both Ti-indiffused and annealed proton-exchanged (APE) waveguide technologies were studied, and waveguide/fiber interfaces were designed to increase the coupling efficiency of the photon pairs into optical fiber. PPLN waveguide devices were fabricated and the optical loss, wavelength conversion efficiency, and heralding efficiency were measured. The maximum heralding efficiencies achieved were 75 and 68% for Ti-indiffused and APE waveguides, respectively. A compact photon pair source based on a packaged PPLN waveguide device and commercially available fiber optic components is presented.

G. Brida, Valentina Caricato, Marco Genovese +2 more

G. Brida, Marco Genovese, KRIVITSKY L. A +2 more

Jeff S. Lundeen, Offir Cohen, Pierre Mahou +2 more

We show that birefringent waveguides, such as optical fibers, allow us to produce photons with desired spectral and spatial characteristics. Tailoring these characteristics is crucial for high-fidelity operation of waveguide quantum logic gates.