Sub-Poisson States Heralded at a Hong-Ou-Mandel Interference Peak

TL;DR

This paper demonstrates a modified Hong-Ou-Mandel interferometer that produces sub-Poissonian photon states with heralding, showing an unusual coincidence peak and photon anti-bunching, advancing quantum state control.

Contribution

It introduces a method to generate sub-Poissonian states using a Hong-Ou-Mandel setup with weak coherent states and heralding, revealing new interference effects.

Findings

Observed a coincidence peak in the HOM interference

Confirmed sub-Poissonian photon statistics via autocorrelation measurements

Demonstrated heralded photon state preparation with reduced photon number fluctuations

Abstract

A peak in coincidence events has been observed in a modified Hong-Ou-Mandel interferometer fed with weak coherent states inside the region of overlapping wave-packets. The inversion of the usual interference pattern represented by the HOM dip is equally observed when the wave packets are frequency displaced. The higher rate of coincidences indicates that photons are more likely to take on different output paths of the interferometer. This effect was harnessed so a detection on one of the arms could herald the presence of a photon in the other. The second order autocorrelation function at zero time was experimentally determined by means of the Hanburry-Brown and Twiss experiment and its value below 1 confirmed the sub-Poisson photon statistics of the heralded states.