Paraxial phasor-field physical optics

Opt Express. 2020 Jul 6;28(14):21095-21109. doi: 10.1364/OE.396577.

Abstract

Phasor-field (P-field) imaging is a promising recent solution to the task of non-line-of-sight (NLoS) imaging, colloquially referred to as "seeing around corners." It consists of treating the oscillating envelope of amplitude-modulated, spatially-incoherent light as if it were itself an optical wave, akin to the oscillations of the underlying electromagnetic field. This resemblance enables traditional optical imaging strategies, e.g., lenses, to be applied to NLoS imaging tasks. To date, however, this ability has only been applied computationally. In this paper, we provide a rigorous mathematical demonstration that P-field imaging can be performed with physical optics, viz., that ordinary lenses can focus or project P fields through intervening diffusers-despite these diffusers' broadly dispersing the light passing through them-and that they can image scenes hidden by such diffusers. Hence NLoS imaging might be carried out via P-field physical optics without the nontrivial computational burden of prior NLoS techniques.