Photonic crystal carpet: Manipulating wave fronts in the near field at 1.55μm

Abstract

Ground-plane cloaks, which transform a curved mirror into a flat one, and recently reported at wavelengths ranging from the optical to the visible spectrum, bring the realm of optical illusion a step closer to reality. However, all carpet-cloaking experiments have thus far been carried out in the far-field. Here, we demonstrate numerically and experimentally that a dielectric photonic crystal (PC) of a complex shape made of a honeycomb array of air holes can scatter waves in the near field like a PC with a flat boundary at stop band frequencies. This mirage effect relies upon a specific arrangement of dielectric pillars placed at the nodes of a quasi-conformal grid dressing the PC. Our carpet is shown to work throughout the range of wavelengths 1500 nm to 1650 nm within the stop band extending from 1280 to 1940 nm. The device has been fabricated using a singlemask advanced nanoelectronics technique on III-V semiconductors and the near field measurements have been carried out in order to image the wave fronts's curvatures around the telecommunication wavelength 1550 nm.

Topological beam-splitting in photonic crystals

“…We operate at telecommunication wavelengths using a photonic crystal (PC) consisting of Indium Phosphide (InP) dielectric pillars in air. Drawing upon the design and fabrication of a dielectric carpet in [32], we contrast two designs of PCs within a square lattice array; the first of which has 6 InP dielectric pillars of diameter 200 nm, height 2µm, and minimum center-to-center spacing of 250nm arranged around an equilateral triangle, Fig. 2(a), and the second has 8 pillars with similar dimensions arranged around a square as in Fig.…”

Compendium on Electromagnetic Analysis

“…As an illustrative example, we consider a square photonic crystal with lattice constant a and with circular air holes drilled in a matrix of permittivity ε m = 11.29 (refractive index n = 3.36). This permittivity value corresponds to the effective index of s-polarized mode in a planar waveguide made of InGaAsP [53]. The radius of the circular holes is set to 0.455a, and this corresponds to the air filling ratio of 0.65.…”

Metallized Porous GaP Templates for Electronic and Photonic Applications

“…26,27 Operation of photonic crystal lenses at infrared wavelengths has also been demonstrated on the basis of InP based photonic crystal technological platform including hole and pillar networks fabrication at nanometer scale. 28 Moreover, a twodimensional device mixing arrays of holes and pillars was evaluated to pave the way for future integrated nanophotonic devices with complex functionalities such as cloaking or routing functions at optical wavelengths, 29 detection and/or imaging. 30…”