Witnessing the survival of time-energy entanglement through biological tissue and scattering media

TL;DR

This study shows that time-energy entanglement of near-IR photons can be preserved through thick biological tissues and scattering media at room temperature, enabling potential advances in biological imaging and quantum measurements.

Contribution

It demonstrates the preservation of quantum entanglement in biological tissues and scattering media, supporting future applications in biological imaging and quantum sensing.

Findings

Entanglement maintained after passing through biological tissue and scattering media.

High interferometric contrast (>0.9) achieved in various media.

Supports potential for nonclassical light applications in biology.

Abstract

We demonstrate the preservation of time-energy entanglement of near-IR photons through thick biological media ($\leq$1.55 mm) and tissue ($\leq$ 235 $\mu$m) at room temperature. Using a Franson-type interferometer, we demonstrate interferometric contrast of over 0.9 in skim milk, 2% milk, and chicken tissue. This work supports the many proposed opportunities for nonclassical light in biological imaging and analyses from sub-shot noise measurements to entanglement-enhanced fluorescence imaging, clearly indicating that the entanglement characteristics of photons can be maintained even after propagation through thick, turbid biological samples.