  Breaking the diffraction limit is always an appealing topic due to the urge
for a better imaging resolution in almost all areas. As an effective solution,
the superlens based on the plasmonic effect can resonantly amplify evanescent
waves, and achieve subwavelength resolution. However, the natural plasmonic
materials, within their limited choices, usually have inherit high losses and
are only available from the infrared to visible wavelengths. In this work, we
have theoretically and experimentally demonstrated that the arbitrary
materials, even air, can be used to enhance evanescent waves and build low loss
superlens with at the desired frequency. The operating mechanisms reside in the
dispersion-induced effective plasmons in a bounded waveguide structure. Based
on this, we constructed the hyperbolic metamaterials and experimentally
verified its validity in the microwave range by the directional propagation and
imaging with a resolution of 0.087 wavelength. We have also demonstrated that
the imaging potential can be extended to terahertz and infrared bands. The
proposed method can break the conventional barriers of plasmon-based lenses and
bring new possibilities to the field of superresolution imaging from microwave
to infrared wavelengths.
