Enhanced Light Absorption in All‐Polymer Biomimetic Photonic Structures by Near‐Zero‐Index Organic Matter

Abstract

Natural photosynthetic photonic nanostructures can show sophisticated light-matter interactions including enhanced light absorption by slow light even for highly pigmented systems. Beyond fundamental biology aspects, these natural nanostructures are very attractive as blueprints for advanced photonic devices. But the soft-matter biomimetic implementations of such nanostructures is challenging due to the low refractive index contrast of most organic photonic structures. Excitonic organic materials with near-zero index (NZI) optical properties allow overcoming these bottlenecks. Here, it is demonstrated that the combination of NZI thin films with photonic multilayers like the ones found in nature enables broadband tunable strong reflectance as well as slow light absorption enhancement and tailored photoluminescence properties in the full VIS spectrum. Moreover, it is shown that this complex optical response is tunable, paving the way toward the development of active devices based on all-polymer and near-zero index materials photonic structures.

Structural color from pigment-loaded nanostructures

“…After exploring a wide range of solvent and polymer combinations, we settled on BC/PS in toluene and polyvinyl alcohol (PVA, n = 1.48 at 550 nm) in water. 27…”

Measuring Photonics in Photosynthesis: Combined Micro-Fourier Image Spectroscopy and Pulse Amplitude Modulated Chlorophyll Fluorimetry at the Micrometre-Scale

“…Paired with the use of an aperture to produce a small illumination area, it is possible to illuminate and collect light from single organelles, but with a large range of angles/k-vectors. The advantage of FIS in the study of natural photonics has been highlighted by the results obtained in the investigation of the reflectance of different types of intracellular natural photonic crystals, like opal-like vesicles in brown algae cells [ 33 ], so-called iridoplasts (chloroplast with photonic crystal-like thylakoid arrangements) [ 24 ] or slab photonic crystals in diatom microalgae [ 26 ].…”

“…The strong blue reflectance in the blue can induce slow-light phenomena in the green, as has been previously demonstrated [ 24 ]. The main consequences are an enhanced light absorption in the green spectral range, which, perhaps essentially, is the spectral range available under the canopy where the species showed live iridoplasts [ 25 , 33 ]. Note that this effect is opposite and counterintuitive to the photoprotective role of photonic structures in many natural systems [ 3 ].…”

Coupling of the Tamm Plasmon to the BODIPY Fluorophore in Photonic Crystals for Nonlinear Optical Applications

“…Research is progressing in enhancing the relatively low refractive index contrast of polymer DBRs that opens a more realistic route to implement a variety of photonic devices . Recent research on photonic multilayer structures fabricated with certain organic J-aggregates having near-zero-index optical properties is a promising implementation in this direction . For our structure, we have chosen PVK and CA, the commercially available polymer pairs that have comparably better dielectric contrasts ( n pvk = 1.68 and n ca = 1.47). , On the TP structure, linear and nonlinear optical characterizations were carried out, and the results were validated by numerical simulations.…”