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In the textbook case of normal diffusion, transport is described as a randomwalk to which all the steps give the same contribution (Brownian motion). Superdiffusion occurs when the transport is dominated by a few, very large steps (Lévy flights). In this regime the variance of the step length distribution diverges and the mean square displacement grows faster than linear with time [1]. Previous works...
A random laser is a system formed by a random assembly of elastic scatters dispersed into an optical gain medium. We consider the case where the scattering is resonant. Our system, a photonic glass, can sustain scattering resonances over the gain frequency window, since it is formed by equal shape and equal size particles (monodisperse spheres) of relatively high refractive index contrast that are...
Three-dimensional icosahedral dielectric photonic quasicrystals previously revealed highly structured transmittance spectra and unusual photon transport properties. Using a periodic approximant approach, we show that all these findings are consistent with multiple scattering of light.
We directly investigate, by means of near-field spectroscopy, the spatial distribution of the optical cavity modes of 2D photonic crystal microcavities. Numerical simulations confirm that the photoluminescence maps of quantum dots embedded in the photonic structure qualitatively match the spatial modulation of the electric field intensity.
We theoretically describe the optical properties of three-dimensional icosahedral photonic quasicrystals by means of a periodic approximant approach. Experimental findings that were previously ascribed to extrinsic effects are found to be intrinsic properties of quasicrystals.
The authors present a novel photonic material dubbed photonic glass, which is a solid, disordered, macroscopic assembly of monodisperse dielectric spheres. These spheres, whose diameter is of the order of the wavelength of the light, support Mie resonances and, as a result of a collective effect of these resonances, the photonic glass is expected to exhibit a resonant behaviour in the diffusion constant...
Our aim is to study the nonlinear properties of micro-structured devices, and focus on second harmonic generation in random dielectric structures. We recently proposed a new method to achieves highly efficient second harmonic generation in random structures. We applied our theoretical results to design, realize and experimentally test a sample made of AlGaAs/AlOx layers grown in a GaAs substrate.
We will give an overview of recently observed analogies between the transport of electrons and light waves and show how complex photonic materials, ranging from periodic to disordered structures can be applied as photonic devices.
In this paper, we overview the recent results in this fascinating field of research. In particular we discuss the recently observed interference effects in partially ordered systems, including the transport of optical pulses in Fibonacci quasi-crystals and the optical analogue of Bloch oscillations. We also discuss the various cases of random lasing and show how diffusive feedback can lead to spectrally...
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