# Coherent quantum frequency bridge: phase preserving, nearly-noiseless parametric frequency converter

Published: May 03, 2017

### Author(s)

Ivan A. Burenkov, Yu-Hsiang Cheng, Tim O. Thomay, Glenn S. Solomon, Alan L. Migdall, Thomas Gerrits, Adriana E. Lita, Sae Woo Nam, Lynden K. Shalm, Sergey V. Polyakov

### Abstract

We characterize an efficient and nearly-noiseless parametric frequency upconverter. The ultra- low noise regime is reached by the wide spectral separation between the input and pump frequencies and the low pump frequency relative to the input photons. The background of only $\approx$100 photons per hour is demonstrated. We demonstrate phase preservation in a frequency upconversion process at the single-photon level. We summarize our efforts to measure this ultra-low noise level, and discuss both single-photon avalanche photodiode measurements and a photon-counting transition edge sensor (TES) measurements. To reach the required accuracy, we supplemented our TES with a dark count reduction algorithm. The preservation of the coherence was demonstrated by simultaneously upconverting the input of each arm of a Mach-Zehnder interferometer through high interference fringe contrast. We observe fringe visibilities of $\geq0.97$ with faint coherent input.
Citation: Proceedings of SPIE Defense and Security Symposium
Volume: 10212
Pub Type: Journals