Experimental observation of the X-shaped near field spatio-temporal correlation of ultra-broadband twin beams

TL;DR

This paper experimentally observes the non-factorable X-shaped spatio-temporal correlation in ultra-broadband twin beams generated by parametric down conversion, confirming theoretical predictions with high-resolution control.

Contribution

It provides the first experimental demonstration of the X-shaped near field spatio-temporal correlation in ultra-broadband twin beams, advancing understanding of their quantum properties.

Findings

Confirmed the X-structure of the correlation experimentally.

Achieved high-resolution control of spatial and temporal degrees of freedom.

Validated theoretical predictions of the correlation structure.

Abstract

In this work we present the experimental observation of the non factorable near field spatio-temporal correlation of ultra-broadband twin beams generated by parametric down conversion (PDC), in an interferometric-type experiment using sum frequency generation, where both the temporal and spatial degrees of freedom of PDC light are controlled with very high resolution. The revealed X-structure of the correlation is in accordance with the predictions of the theory.