Work

Scattering zones in quantum speckle propagation

Year: 2026

Type: article

Abstract: Quantum speckles exhibit significantly richer behavior than their classical counterparts due to their higher dimensionality. A simple example is the far-field speckle pattern in one-dimensional (1D) light scattering: Classical light forms 1D speckles defined by the numerical aperture, whereas biphoton scattering depends in addition on the photon correlation length, forming two-dimensional elliptical speckles. To date, the behavior of quantum speckles for shorter propagation distances has not been considered. We remedy this here by considering the paraxial evolution of two-photon entanglement at arbitrary propagation distances from a scatterer. We show, theoretically, numerically, and experimentally, that the two length scales of the biphoton introduce a new Fresnel regime between the conventional near and far fields. Further, we show that the quantum near field is characterized by speckles with a square shape that remain constant during propagation. In contrast, the intermediate regime can be engineered to have a constant speckle size along the sum coordinate but a linearly expanding speckle size along the difference coordinate, with a speckle shape that transitions from square to elliptical. The results merge quantum coherence with scattering statistics and suggest new regimes of operation for correlation-based quantum sensing and imaging.

Source: Physical Review Research

DOI: 10.1103/ymwh-j65z

Authors: Shaurya Aarav, S. A. Wadood, Jason W. Fleischer

Institution: Princeton University

Language: English

Topic: Random lasers and scattering media

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,625

Funder: Air Force Office of Scientific Research