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Subwavelength position sensing using nonlinear feedback and wave chaos
Seth D Cohen1, Hugo L D de S Cavalcante, Daniel J Gauthier
1Department of Physics, Duke University, Durham, North Carolina 27708, USA.
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.
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