Three Dimensional Subwavelength focus by a near-field plate lens
arXiv:1305.5123 · doi:10.1063/1.4810004
Abstract
We implemented the inverse design method to build a thin near-field lens that could produce a desired subwavelength focus by manipulating the near fields of a magnetic dipole source. The flat near-field lens represented by an artificial impedance surface was fabricated by lumped reactive elements (capacitor and inductor) with spatially varying values. In the experiment a desired annular focusing spot with a characteristic size nearly three times smaller than that allowed by the diffraction limit was obtained. Besides high-resolution imaging, the proposed near-field plate could be extended for other interesting applications, such as wireless power transfer or complex wavefront/beam shaper.
5 figures
References in corpus (6)
- Aberration-free ultra-thin flat lenses and axicons at telecom wavelengths based on plasmonic metasurfaces
- Circuit elements at optical frequencies: nano-inductors, nano-capacitors and nano-resistors
- Reconciliation of generalized refraction with diffraction theory
- Giant birefringence in optical antenna arrays with widely tailorable optical anisotropy
- An omnidirectional retroreflector based on the transmutation of dielectric singularities
- Near-Field Focusing Plates and Their Design