title: Subwavelength position sensing using nonlinear feedback and wave chaos.
abstract: We demonstrate a position-sensing technique that relies on the inherent sensitivity of chaos, where we illuminate a subwavelength object with a complex structured radio-frequency field generated using wave chaos and nonlinear feedback. We operate the system in a quasiperiodic state and analyze changes in the frequency content of the scalar voltage signal in the feedback loop. This allows us to extract the object's position with a one-dimensional resolution of ~λ/10,000 and a two-dimensional resolution of ~λ/300, where λ is the shortest wavelength of the illuminating source.
authors.affiliation: Department of Physics, Duke University, Durham, North Carolina 27708, USA.
authors.forename: Seth D
authors.initials: SD
authors.lastname: Cohen
authors.forename: Hugo L D de S
authors.initials: HL
authors.lastname: Cavalcante
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Gauthier