Interface engineering for improved light transmittance through photonic crystal flat lenses

2010

In this paper, we present photonic crystal flat lenses with interfaces engineered to improve the light transmittance thanks to a broad angles impedance matching. The interface engineering consists in the realization of antireflection gratings on the edges of the lenses which are designed to reduce the propagative waves reflectivity over a wide range of incident angles. The fabricated structures were measured in optical near-field and a four times enhancement of the light transmission efficiency is reported.

Optical near-field microscopy of light focusing through a photonic crystal flat lens

2008

We report here the direct observation by using a scanning near-field microscopy technique of the light focusing through a photonic crystal flat lens designed and fabricated to operate at optical frequencies. The lens is fabricated using a III-V semiconductor slab, and we directly visualize the propagation of the electromagnetic waves by using a scanning near-field optical microscope. We directly evidence spatially, as well as spectrally, the focusing operating regime of the lens. At last, in light of the experimental scanning near-field optical microscope pictures, we discuss the lens ability to focus light at a subwavelength scale.

Etude en champ proche optique du tapis d'invisibilité de Li/Pendry

2013