Near-field observation of beam steering in a photonic crystal superprism

Abstract

The optical near-field technique is applied to provide a direct experimental observation of the refracted beam propagation inside a photonic crystal structure displaying a superprism effect. The obtained results show a 35° light beam angle deviation for a wavelength variation from 1500 to 1600 nm. The experimentally determined beam divergence is in good agreement with modeling predictions and previously performed transmittance experiments. A marked self-collimation propagation over a broad 20 nm wide spectral range centered at λ=1550 nm is experimentally demonstrated. The developed technique opens promising perspectives for the invisibility cloaking structures investigation.

Hyperspectral optical near-field imaging: Looking graded photonic crystals and photonic metamaterials in color

“…As a result, it is found that the output beam shifts almost linearly with a slope of 0.25 lm/nm in the 1470-1600 nm spectral range without noticeable spatial or spectral spreading. This dispersion value is comparable to the one achievable, thanks to the PhC superprism effect 22 over almost the same propagation length about 0.4 lm/nm, but the strong beam spreading inherent to the superprism effect appears here drastically reduced.…”

2D Waveguided Bessel Beam Generated Using Integrated Metasurface-Based Plasmonic Axicon

“…34,35 The conventional approach relies on self-collimation properties that can be obtained using 2D photonic crystal (PhC) structures. 36,37,38 However, its application is essentially limited to the propagation of single lobe Gaussian beams. The implementation of Bessel type profile requires an adaptation of both the phase and amplitude of the wavefront at the subwavelength scale.…”

Graded index photonic crystals: A review

“…Since the discovery of PC in 1987 , photonic crystals have met a rapidly growing research interest, and many PC‐based applications are proposed. These applications include spontaneous emission , filters , focusing , mirrors , self collimation , solar energy trapping , superprism and waveguide etc .…”