Sunlight-Excited Spontaneous Parametric Down-Conversion for Quantum Imaging

TL;DR

This paper demonstrates that sunlight can be used as a pump source for spontaneous parametric down-conversion, enabling quantum imaging with incoherent light, which broadens potential applications including space-based quantum systems.

Contribution

It introduces the novel concept of using sunlight as a pump for quantum imaging, expanding the range of feasible illumination sources for quantum information applications.

Findings

Sunlight can produce well-correlated photon pairs suitable for quantum imaging.

Photon pairs generated from sunlight exhibit strong positional correlations.

This approach enables quantum imaging without the need for coherent laser sources.

Abstract

Quantum imaging, which harnesses quantum correlations to achieve imaging with multiple advantages over classical optics, has been in development for several years. Here, we explore sunlight, serving as the pump beam, to excite spontaneous parametric down-conversion to get the quantum correlation of two photons. Remarkably, our investigations disclose that the photon pairs produced from sunlight are well correlated in position such that they can be used for quantum imaging. Consequently, this demonstrates a latent application scenario in which the incoherent beam is harnessed as the pump source for quantum imaging. Our research is of substantial significance as it broadens the scope of available illumination options, such as using scattering light or non-traditional artificial incoherent light sources, for quantum information, a prime potential application being a space-based quantum information mechanism where this approach allows the system to operate independently of a laser.