Development of quantum technologies for optical/infrared interferometry

Abstract

Quantum technologies may revolutionize optical interferometry through new means to distribute and preserve electric-field amplitude and phase correlations between widely separated telescopes. After reviewing existing techniques, I survey proposed quantum-sensing and quantum-networking applications and highlight recent laboratory demonstrations of key building blocks. By easing field-transport demands for baselines beyond ∼1km, quantum-enhanced interferometry could enable sub-milliarcsecond imaging and μas-class differential astrometry. That said, “going quantum” is not a magic shortcut to sensitivity because many of the most compelling science cases remain photon- and turbulence-limited. I therefore emphasize the practical constraints – loss, bandwidth, coherence time, synchronization, and wavelength limits of quantum interfaces – that must also be overcome to make these capabilities useful for astronomy, whether deployed on the ground or from space.