Experimental Demonstrations of Coherence de Broglie Wavelength for Scalable Superresolution with Near-perfect Fringe Visibility

Quantum sensing and metrology have been intensively studied over the last several decades to surpass the fundamental shot-noise limit of classical systems and approach the Heisenberg limit. However, implementation of N00N-state-based quantum sensing has been severely constrained by the limited order N , intrinsically imperfect fringe visibility, and vulnerability to photon loss. Recently, the coherence de Broglie wavelength (CBW) has been proposed as an alternative method for achieving superresolution in a coherently coupled interferometer architecture, whose characteristics resemble those of the photonic de Broglie wavelength (PBW) used in quantum sensing. Here, we experimentally demonstrate scalable CBW superresolution up to N =3, with near-perfect fringe visibility that is invariant to photon loss. The observed CBWs have the potential to enable a superresolution sensing platform even if it remains within the shot-noise limit.