Photonic crystal carpet: Manipulating wave fronts in the near field at 1550 nm

TL;DR

This paper demonstrates a dielectric photonic crystal carpet that manipulates near-field wave fronts at 1550 nm, enabling optical illusions and wave control in the near field through both numerical simulations and experimental validation.

Contribution

It introduces a novel photonic crystal design with a honeycomb structure that achieves near-field wave front manipulation at telecommunication wavelengths, extending cloaking concepts to the near field.

Findings

Effective near-field wave front manipulation at 1550 nm

Fabrication of the device using advanced nanoelectronics techniques

Experimental imaging of wave front curvatures confirming the design

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 at 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 1500nm to 1650nm within the stop band extending from 1280 to 1940 nm. The device has been fabricated using a single- mask 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.