Heralded Source of Bright Multi-mode Mesoscopic Sub-Poissonian Light

TL;DR

This paper demonstrates a heralded source of bright, multi-mode, sub-Poissonian light with significant squeezing and low noise, suitable for advanced metrology and nonlinear optical applications.

Contribution

It presents a method to generate and conditionally prepare multi-mode sub-Poissonian light with high photon numbers using parametric down conversion and post-selection.

Findings

7.8 dB twin-beam squeezing observed

Prepared states contain approximately 630,000 photons per pulse

Pulse energy uncertainty is below shot-noise level

Abstract

In a direct detection scheme we observed 7.8 dB of twin-beam squeezing for multi-mode two-color squeezed vacuum generated via parametric down conversion. Applying post-selection, we conditionally prepared a sub-Poissonian state of light containing $6.3\cdot10^5$ photons per pulse on the average with the Fano factor $0.63\pm0.01$. The scheme can be considered as the heralded preparation of pulses with the mean energy varying between tens and hundreds of fJ and the uncertainty considerably below the shot-noise level. Such pulses can be used in metrology (for instance, for radiometers calibration) as well as for probing multi-mode nonlinear optical effects.