Retrieving time-dependent Green's functions in optics with low-coherence interferometry

TL;DR

This paper demonstrates a passive optical method using low-coherence interferometry to measure time-dependent Green's functions in complex media, enabling improved imaging and characterization.

Contribution

It introduces a novel passive optical technique to directly retrieve Green's functions in complex scattering media using broadband incoherent waves.

Findings

Successfully retrieves both ballistic and multiple scattering components.

Enables non-invasive optical imaging in complex media.

Bridges concepts from acoustics and seismology to optics.

Abstract

We report on the passive measurement of time-dependent Green's functions in the optical frequency domain with low-coherence interferometry. Inspired by previous studies in acoustics and seismology, we show how the correlations of a broadband and incoherent wave-field can directly yield the Green's functions between scatterers of a complex medium. Both the ballistic and multiple scattering components of the Green's function are retrieved. This approach opens important perspectives for optical imaging and characterization in complex scattering media.