Materials with a high index of refraction in the visible spectrum of electromagnetic field are strongly sought for their potentially revolutionary impact on optical devices. In microscopy, the minimum resolution of an optical microscope scales with index of refraction, so that a giant index of refraction makes even a rudimentary table-top microscope capable of directly observing nanoscale objects. In solar-panel technology, the higher the index of refraction, the stronger the focusing of solar light and the more efficient the energy harvesting. In optical quantum technology, giant indexes of refraction promise stronger localization and the opportunity of achieving photon-to-photon interaction. In image transmission, a giant index of refraction effectively halts distortions associated to diffraction. In a recent set of experiments, we have demonstrated that a nanodisordered ferroelectric perovskite (KTN:Li) can manifest a giant index of refraction (n>26) for the whole visible spectrum. The material is able to project visible light, of any color, and even white incoherent light, from its input to its output, without diffraction and chromatic dispersion, irrespective of beam size, numerical aperture , wavelength, coherence (from single-mode laser to white projector lamp light), intensity, and input direction (input angles up to -40 to 40 degrees to the normal). The giant index causes the material to become an ideal imaging device: for light, it is as if the input and output facets of the material coincide. The goal of this proposal is to implement broadband giant refraction to achieve a basic building block in what could be termed a white-light photonics, an all-purpose achromatic white-light transducer. The white-light transducer will be able to transfer with maximum efficiency light from any angle of incidence to a photosensitive sensor, irrespective of the input angle, achieving, for example, a self-aligning imaging system or a self-aligning solar panel.
The added feature of self-alignment in optical image detection brings with it the possibility of increasing the cost effectiveness of solar panel devices by reducing the need for mechanical movements. It can further allow the introduction of a protecting dielectric layer, a form of cladding, on the panel that in fact introduces no added distortions. For imaging, the idea of not having to reorient the detecting surface as the source moves implies the possibility of imaging rapidly moving objects with need for mechanical movements.
Optical transducers that operate on GR introduce an entire new concept in photonics: achromatic white light photonics. Just to give an example of what this implies, consider that in order to guide a broadband field a multi-mode waveguide inherently incurs in mode dispersion. The result is a limit on transmission bit rate. In turn, a GR waveguide transfers light with no diffraction not because mode are excited, but simply because diffraction is rendered negligible along the length of the sample, so that no modal dispersion intervenes. The result is an integrated photonics with no limit on transmission bit associate to modal dispersion.