Transverse coherence of photon pairs generated in spontaneous parametric down-conversion

TL;DR

This paper investigates the transverse coherence of photon pairs generated via spontaneous parametric down-conversion, comparing experimental measurements with a theoretical model to understand and control the correlation area shape.

Contribution

It provides a detailed experimental and theoretical analysis of the coherence properties of down-converted photons, enabling tailored correlation areas through pump and crystal parameters.

Findings

Correlation area shape can be controlled by pump and crystal parameters.

Splitting of correlation area observed with a two-peak pump spectrum.

Experimental results agree with the theoretical model.

Abstract

Coherence properties of the down-converted beams generated in spontaneous parametric down-conversion are investigated in detail using an iCCD camera. Experimental results are compared with those from a theoretical model developed for pulsed pumping with a Gaussian transverse profile. The results allow to tailor the shape of correlation area of the signal and idler photons using pump-field and crystal parameters. As an example, splitting of a correlation area caused by a two-peak pump-field spectrum is experimentally studied.