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Statistically background-free, phase-preserving parametric up-conversion with faint light



Yu-Hsiang Cheng, Tim O. Thomay, Glenn S. Solomon, Alan L. Migdall, Sergey Polyakov


We demonstrate phase preservation in a frequency up-conversion process at the single-photon level. This phase preservation enables the applications of frequency conversion of entangled photon pairs. Periodically poled lithium niobate waveguides and a 1550 nm pump laser are employed to convert near infrared 920 nm photons into the visible at 577 nm. Using a Mach-Zehnder interferometer, whose input wavelengths differ from the output, fringe visibilities of  >=0.97 were observed. Within the available range of pump power and up-conversion efficiency, no statistically significant background photons near the up-converted wavelength due to the strong pump were detected in our experimental setup.
Optics Express


quantum information and processing, parametric up-conversion, phase preservation, background-free


Cheng, Y. , Thomay, T. , Solomon, G. , Migdall, A. and Polyakov, S. (2015), Statistically background-free, phase-preserving parametric up-conversion with faint light, Optics Express, [online],, (Accessed June 19, 2024)


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Created July 8, 2015, Updated October 14, 2021