Towards large-scale entanglement-enhanced interferometry

Abstract

We report progress measuring Earth’s rotation with entangled photons. In our 2 km fiber Sagnac interferometer, we achieve milliradian sensitivity with cw light, find a preliminary signal, and work towards injecting 2-photon NOON states.

Controlling two-photon interference and entanglement with mechanical rotations

“…16 A Sagnac phase shift on a two-photon NOON state was observed in, 17 and the current sensitivities allow the measurement of the Earth's daily rotation. 18 Here we review how mechanical rotations affect photon bunching in a Hong-Ou-Mandel (HOM) setup. It was shown that the temporal distinguishability of photons is affected by low-frequency mechanical rotations resulting in a shift of the HOM dip.…”