Near‐Field Investigation of Luminescent Hyperuniform Disordered Materials

Abstract

Disordered photonic nanostructures have attracted tremendous interest in the past three decades, not only due to the fascinating and complex physics of light transport in random media, but also for peculiar functionalities in a wealth of interesting applications. Recently, the interest in dielectric disordered systems has received new inputs by exploiting the role of long‐range correlation within scatterer configurations. Hyperuniform photonic materials, that share features of photonic crystals and random systems, constitute the archetype of systems where light transport can be tailored from diffusive transport to a regime dominated by light localization due to the presence of photonic band gap. Here, advantage is taken of the combination of the hyperuniform disordered (HuD) design in slab photonics, the use of embedded quantum dots for feeding the HuD resonances, and near‐field hyperspectral imaging with sub‐wavelength resolution in the optical range to explore the transition from localization to diffusive transport. It is shown, theoretically and experimentally, that photonic HuD systems support resonances ranging from strongly localized modes to extended modes. It is demonstrated that Anderson‐like modes with high Q/V are created, with small footprint, intrinsically reproducible and resilient to fabrication‐induced disorder, paving the way for a novel photonic platform for quantum applications.

Engineering high Q/V photonic modes in correlated disordered systems

“…A remarkable example of this innovative feature can be seen in the design (Fig. 1a), where the central defect is spatially near to an accidental topological defect (here, a cell of the HuD network with four edges, rather than the average six), typical of stealthy HuD systems [5]. This is an unavoidable defect that depends on the tiling protocol employed to generate the pattern, and it is the first of many tightly localized modes occurring at the PB edge.…”

“…They have recently been shown to display large isotropic band gaps (BG) as well as optical transparency, to mention two of the most fascinating and promising features. Among the several experimental photonic realizations of HuD structures [3,4], also HuD systems on dielectric slabs have been recently proposed [5] and characterized as photonic materials capable of combining the small spatial footprint typical of random modes with Q/V ratios comparable with photonic crystal cavities for the Anderson-localized modes naturally occurring at the BG edges. These modes with relatively high Q, however do not have predictable spatial locations in the whole structure.…”

Correlated Disorder Substrate‐Integrated Nanodisk Scatterers for Light Extraction in Organic Light Emitting Diodes

“…The nanodisks are arranged in a correlated disorder configuration, ensuring on the one hand structural correlations that are beneficial to the scattering properties, and on the other hand in-plane isotropy. [30,31] Hence, the emission patterns are invariant with respect to the azimuthal angle and do not introduce unwanted effects such as butterfly-like emission patterns. Based on our experimental findings, we include an in-depth numerical analysis where we focus on the properties of the individual scatterer, and make suggestions on improving the latter.…”

Extraordinary disordered hyperuniform multifunctional composites

“…Disordered hyperuniform materials can have advantages over crystalline ones, such as unique or nearly optimal, direction-independent physical properties and robustness against defects. 16,22,[25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41][42] The hyperuniformity concept was generalized to twophase heterogeneous media in d-dimensional Euclidean space R d , 24,43 which include composites, cellular solids and porous media. A two-phase medium in R d is hyperuniform if its local volume-fraction variance σ 2…”