Coherence area profiling in multi-spatial-mode squeezed states

TL;DR

This paper presents a practical method to map and control the spatial distribution of entangled modes in multi-spatial-mode squeezed states generated by four-wave mixing, enhancing their application in sensing and imaging.

Contribution

It introduces an accessible technique to map coherence areas and demonstrates how pump shaping influences noise properties and enables selection of optimal squeezing regions.

Findings

Mapped the distribution of coherence areas in twin beams.

Showed pump shape affects noise properties of coherence areas.

Enabled selection of coherence areas with optimal squeezing.

Abstract

The presence of multiple bipartite entangled modes in squeezed states generated by four wave mixing in atomic vapors enables ultra-trace sensing, imaging, and metrology applications that are impossible to achieve with single-spatial-mode squeezed states. For Gaussian seed beams, the spatial distribution of bipartite entangled modes, or coherence areas, across each beam is largely dependent on the spatial modes present in the pump beam, but it has proven difficult to map the distribution of these coherence areas in frequency and space. We demonstrate an accessible method to map the distribution of the coherence areas within these twin beams. We also show that the pump shape can impart different noise properties to each coherence area, and that it is possible to select and detect coherence areas with optimal squeezing with this approach.