Broadband coherent backscattering spectroscopy of the interplay between order and disorder in three-dimensional opal photonic crystals

Abstract

We present an investigation of coherent backscattering of light that is multiple scattered by a photonic crystal by using a broad-band technique. The results significantly extend on previous backscattering measurements on photonic crystals by simultaneously accessing a large frequency and angular range. Backscatter cones around the stop gap are successfully modelled with diffusion theory for a random medium. Strong variations of the apparent mean free path and the cone enhancement are observed around the stop band. The variations of the mean free path are described by a semi-empirical three-gap model including band structure effects on the internal reflection and penetration depth. A good match between theory and experiment is obtained without the need of additional contributions of group velocity or density of states. We argue that the cone enhancement reveals additional information on directional transport properties that are otherwise averaged out in diffuse multiple scattering.

Disorder-Immune Photonics Based on Mie-Resonant Dielectric Metamaterials

“…As a result, the impact of disorder on such photonic structures has extensively been studied, both numerically and experimentally . When the disorder is small enough (up to a few percent of the lattice constant) and can be treated as a perturbation, the interaction between the order and disorder gives rise to interesting optical transport phenomena involving multiple light scattering, diffusion and localization of light [16][17][18][20][21][22][23][24]. As disorder is increased further, the photonic bandgap is destroyed, owing to the adverse effect to the Bragg reflection [25][26][27][28][29][30][31][32][33].…”

Disorder-Immune Photonics Based on Mie-Resonant Dielectric Metamaterials

“…As a result, the impact of disorder on such photonic structures has extensively been studied, both numerically and experimentally . When the disorder is small enough (up to a few percent of the lattice constant) and can be treated as a perturbation, the interaction between the order and disorder gives rise to interesting optical transport phenomena involving multiple light scattering, diffusion and localization of light [15][16][17][18][19][20][21][22]. As disorder is increased further, the photonic bandgap is destroyed, owing to the adverse effect to the Bragg reflection [23][24][25][26][27][28][29][30][31].…”

Weak Localization of Light in Superdiffusive Random Systems

“…Among all interference phenomena in random optical materials, maybe the most robust is that of weak localization [16]. It is observed in the form of a cone of enhanced backscattering, which contains information on the path length distribution deep inside the random sys-tem, and which has been observed in recent years from several diffusive random structures [18][19][20][21][22][23][24][25] Some of us have recently shown theoretically that weak localization, or coherent backscattering, can be observed from Lévy glasses and that a superdiffusive approximation can be used to predict its behaviour [26]. In this paper we report on the experimental observation of weak localization from superdiffusive materials, which constitutes the first observation of an interference effect in transport based on Lévy statistics.…”