Photorealistic ray tracing of free-space invisibility cloaks made of uniaxial dielectrics

Optics Express (Impact Factor: 3.49). 12/2012; 20(27):28330-40. DOI: 10.1364/OE.20.028330
Source: PubMed


The design rules of transformation optics generally lead to spatially inhomogeneous and anisotropic impedance-matched magneto-dielectric material distributions for, e.g., free-space invisibility cloaks. Recently, simplified anisotropic non-magnetic free-space cloaks made of a locally uniaxial dielectric material (calcite) have been realized experimentally. In a two-dimensional setting and for in-plane polarized light propagating in this plane, the cloaking performance can still be perfect for light rays. However, for general views in three dimensions, various imperfections are expected. In this paper, we study two different purely dielectric uniaxial cylindrical free-space cloaks. For one, the optic axis is along the radial direction, for the other one it is along the azimuthal direction. The azimuthal uniaxial cloak has not been suggested previously to the best of our knowledge. We visualize the cloaking performance of both by calculating photorealistic images rendered by ray tracing. Following and complementing our previous ray-tracing work, we use an equation of motion directly derived from Fermat's principle. The rendered images generally exhibit significant imperfections. This includes the obvious fact that cloaking does not work at all for horizontal or for ordinary linear polarization of light. Moreover, more subtle effects occur such as viewing-angle-dependent aberrations. However, we still find amazingly good cloaking performance for the purely dielectric azimuthal uniaxial cloak.

Download full-text


Available from: Jad C Halimeh, Apr 08, 2015

Click to see the full-text of:

Article: Photorealistic ray tracing of free-space invisibility cloaks made of uniaxial dielectrics

8.8 MB

See full-text
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Carpet or ground-plane invisibility cloaks hide an object in reflection and inhibit transmission experiments by construction. This concept has significantly reduced the otherwise demanding material requirements and has hence enabled various experimental demonstrations. In contrast, free-space invisibility cloaks should work in both reflection and transmission. The fabrication of omnidirectional three-dimensional free-space cloaks still poses significant challenges. Recently, the idea of the carpet cloak has been carried over to experiments on unidirectional free-space invisibility cloaks that only work perfectly for one particular viewing direction and, depending on the design, also for one linear polarization of light only. Here, by using photorealistic ray tracing, we visualize the performance of four types of such unidirectional cloaks in three dimensions for different viewing directions and different polarizations of light, revealing virtues and limitations of these approaches in an intuitive manner.
    Optics Express 04/2013; 21(8):9457-72. DOI:10.1364/OE.21.009457 · 3.49 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Invisibility has been a tantalizing concept for mankind over several centuries. With recent developments in metamaterial science and nanotechnology, the possibility of cloaking objects to incoming electromagnetic radiation has been escaping the realm of science fiction to become a technological reality. In this article, we review the state-of-the-art in the science of invisibility for electromagnetic waves, and examine the different available technical concepts and experimental investigations, focusing on the underlying physics and the basic scientific concepts. We discuss the available cloaking methods, including transformation optics, plasmonic and mantle cloaking, transmission-line networks, parallel-plate cloaking, anomalous resonance methods, hybrid methods and active schemes, and give our perspective on the subject and its future. We also draw a parallel with cloaking research for acoustic and elastodynamic waves, liquid waves, matter waves and thermal flux, demonstrating how ideas initiated in the field of electromagnetism have been able to open groundbreaking venues in a variety of other scientific fields. Finally, applications of cloaking to noninvasive sensing are discussed and reviewed.
    Progress In Electromagnetics Research 01/2014; 147:171-202. DOI:10.2528/PIER15011403 · 1.23 Impact Factor