Broadband transfer of binary images via optically long wire media

In the paper the binary mechanism of the long-distance image transfer in a wire-medium (WM) endoscope is suggested and studied. We have shown that a discrete image formed by a set of point sources TM-polarized with respect to the WM can be transferred from the input to the output of the endoscope in a very broad frequency band. The underlying physics is the formation of local channels by a group of four adjacent wires. It allows the transfer of the near field beyond the Fabry-Perot resonances at which the known canalization mechanism offers the image. Both numerical simulations and experimental measurements confirm the deeply subwavelength resolution on the output WM interface. The binary imaging was studied until the frequencies at which the endoscope length exceeds 5λ. The transfer is possible in the entire investigated frequency range (from 1 up to 4 GHz) except for the frequencies where the Fabry-Perot resonance are not enough suppressed.