Witnessing The Survival Of Time-Energy Entanglement Through Biological Tissue And Scattering Media

We demonstrate the preservation of the time-energy entanglement of near-IR photons through thick biological media (<= 1.55 mm) and tissue (<= 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. (C) 2021 Optical Society of America under the terms of the OSA Open Access Publishing Agreement