Single-Mode Parametric-Down-Conversion States with 50 Photons as a Source for Mesoscopic Quantum Optics

TL;DR

This paper reports the generation and measurement of high-photon-number two-mode squeezed states in a single mode, demonstrating advanced photon-number correlation measurements with high efficiency in the telecom regime, advancing mesoscopic quantum optics research.

Contribution

The study introduces a method to produce and measure single-mode parametric-down-conversion states with up to 50 photons, achieving high detection efficiency and high-order correlation functions.

Findings

Generated states with up to 20 mean photons per mode.

Measured photon-number correlations up to 80 photons per mode.

Achieved detection efficiency of 64% in the telecom regime.

Abstract

We generate pulsed, two mode squeezed states in a single spatio-temporal mode with mean photon numbers up to 20. We directly measure photon-number-correlations between the two modes with transition edge sensors up to 80 photons per mode. This corresponds roughly to a state-dimensionality of 6400. We achieve detection efficiencies of 64% in the technologically crucial telecom regime and demonstrate the high quality of our measurements by heralded nonclassical distributions up to 50 photons per pulse and calculated correlation functions up to 40th order.