A5016185856- Metamaterials and Metasurfaces Applications
- Photonic Crystals and Applications
- Plasmonic and Surface Plasmon Research
- Photonic and Optical Devices
- Advanced Antenna and Metasurface Technologies
- Nonlinear Optical Materials Research
- Nonlinear Optical Materials Studies
- Antenna Design and Analysis
- Spectroscopy and Quantum Chemical Studies
- Optical Coatings and Gratings
- Advanced Materials and Mechanics
- Liquid Crystal Research Advancements
- Photorefractive and Nonlinear Optics
- Orbital Angular Momentum in Optics
- Electromagnetic Scattering and Analysis
- Molecular spectroscopy and chirality
- Supramolecular Self-Assembly in Materials
- Strong Light-Matter Interactions
- Advanced Fiber Laser Technologies
- Metal-Organic Frameworks: Synthesis and Applications
- Advanced biosensing and bioanalysis techniques
- Nanofabrication and Lithography Techniques
- Organic and Molecular Conductors Research
- Molecular Junctions and Nanostructures
- Random lasers and scattering media
Karlsruhe Institute of Technology
2019-2024
EdgeWave (Germany)
2020
Researchers routinely sense molecules by their infrared vibrational "fingerprint" absorption resonances. In addition, the dominant handedness of chiral can be detected circular dichroism (CD), normalized difference between optical response to incident left- and right- handed circularly polarized light. Here, we introduce a cavity composed two parallel arrays helicity-preserving silicon disks that allows one enhance CD signal more than 2 orders magnitude for given molecule concentration...
Abstract Optical metasurfaces consist of 2D arrangements scatterers, and they control the amplitude, phase, polarization an incidence field on demand. are cornerstone for a future generation flat optical devices in wide range applications. The rapid advances nanofabrication have made versatile design analysis these ultra‐thin surfaces ever‐growing necessity. However, comprehensive theory to describe response periodic closed‐form analytical expressions has not been formulated, prior attempts...
Abstract An approach is presented to align the direction of liquid crystal networks or elastomers in situ during multi‐photon laser printing for each voxel three dimensions by applying a quasi‐static electric field with variable orientation. This enables making 3D micro‐heterostructures operating under ambient conditions that show large‐amplitude elastic actuation, temperature serving as stimulus (“4D microstructures”). The involves two novelties. First, dedicated sample cell height suitable...
Abstract Thin films sustaining plasmonic circular dichroism (PCD) have acquired high scientific relevance and a great potential for applications. While most efforts in PCD thin film structures focus on lithographically fabricated static metasurfaces, the bottom‐up fabrication of active chiral constitutes an alternative approach. Herein, preparation by melting freezing mixture liquid crystal (LC), dopant, gold nanoparticles (Au NPs), serving as helical matrix, symmetry breaking inducer,...
Predicting the optical response of macroscopic arrangements individual scatterers is a computational challenge, as problem involves length scales across multiple orders magnitude. We present full-wave method to highly efficiently compute scattering light at objects that are arranged in bi-periodic arrays. Multiple arrays or homogeneous thin-films can be stacked build up an entire multicomposite material third dimension. The properties each array described by T-matrix formalism. Therefore,...
The recent fabrication advances in nanoscience and molecular materials point toward a new era where material properties are tailored silico for target applications. To fully realize this potential, accurate computationally efficient theoretical models needed for: a) the computer-aided design optimization of before their fabrication; b) interpretation experiments. development such is challenging multi-disciplinary problem physics, chemistry, science intertwined across spatial scales ranging...
Abstract Metasurfaces with bound states in the continuum (BICs) have proven to be a powerful platform for drastically enhancing light–matter interactions, improving biosensing, and precisely manipulating near- far-fields. However, engineering metasurfaces provide an on-demand spectral angular position BIC remains prime challenge. A conventional solution involves fine adjustment of geometrical parameters, requiring multiple time-consuming calculations. In this work, circumvent such tedious...
Abstract We outline a methodology for efficiently computing the electromagnetic response of molecular ensembles. The is based on link that we establish between quantum‐chemical simulations and transfer matrix (T‐matrix) approach, common tool in physics engineering. exemplify analyze accuracy by using time‐dependent Hartree‐Fock theory simulation data single chiral molecule to compute T‐matrix cross‐like arrangement four copies molecule, then circular dichroism cross. results are very good...
Liquid crystal elastomers (LCEs) are highly suitable materials for the fabrication of flexible photonic elements due to their ability directional actuation induced by external stimuli. 3D laser printing (3DLP) is a well-established method realize complex architectures. In this paper, we present technological adaptations necessary combine actuation-controlled flexibility LCE with design options inherent 3DLP platform tunable photonics. The role birefringence in addressed and theoretically...
Abstract Electronic circular dichroism is an important optical phenomenon offering insights into chiral molecular materials. On the other hand, metal–organic frameworks (MOFs) are a novel group of crystalline porous thin‐film materials that provide tailor‐made chemical and physical properties by carefully selecting their building units. Combining these two aspects contemporary material research integrating molecules MOFs promises devices with unprecedented functionality. However, considering...
Abstract The accurate and efficient computation of the electromagnetic response objects made from artificial materials is crucial for designing photonic functionalities interpreting experiments. Advanced fabrication techniques can nowadays produce new as 3D lattices scattering unit cells. Computing arbitrary shape such typically computationally prohibitive unless an effective homogeneous medium approximates discrete material. In here, a homogenization method based on transition (T‐)matrix,...
In this article, we analyze polarization-dependent effects in vibrational absorption spectra of 2D finite-size adsorbate islands on dielectric substrates. Using a multi-scale approach, predict the transition from to monolayer.
Exploring the interaction of light with materials periodically structured in space and time is intellectually rewarding and, simultaneously, a computational challenge. Appropriate tools are urgently needed to explore how such upcoming photonic can control on demand. Here, we introduce semi-analytical approach based transition matrix (also known as T-matrix) analyze optical response spatiotemporal metasurface. The metasurface consists periodic arrangement time-varying scattering particles. In...
In recent years, multi-photon 3D laser printing has become a widely used tool for the fabrication of micro- and nanostructures large variety applications. Typically, thorough sample characterisation is key an efficient optimisation process. To date, three-dimensional microscopic inspection usually been carried out on finished printed microstructures, that is, using ex-situ approaches. contrast, in-situ characterization tools are desirable quickly assessing quality properties microstructures....
The evaluation of the interaction between objects arranged on a lattice requires computation sums. A scenario frequently encountered are systems governed by Helmholtz equation in context electromagnetic scattering an array particles forming metamaterial, metasurface, or photonic crystal. While convergence direct sums for such translation coefficients is notoriously slow, application Ewald's method converts into exponentially convergent series. We present derivation series 2D and 3D solutions...
Nonlinear optics is essential for many recent photonic technologies. Here, a novel multi-scale approach introduced to simulate the nonlinear optical response of molecular nanomaterials combining ab initio quantum-chemical and classical Maxwell-scattering computations. In this approach, first hyperpolarizability tensor computed with time-dependent density-functional theory incorporated into multi-scattering formalism that considers interaction between neighboring molecules. Such incorporation...
Being able to sense and distinguish the handedness of chiral molecules is crucial for many applications in life sciences. Here, we explore by theoretical computational means ability achiral helicity preserving photonic nanostructures enhance optical rotation, i.e., polarization rotation elliptically polarized light while traversing a solution molecules. Starting from isolated dielectric cylinder, assemble an array thereof, which enhances power factor four, being limited inability density...
Liquid crystalline (LC) dimers formed helical nanofilaments depending on the parity of alkyl linker, revealing an unusual odd-even effect. Molecular dynamics simulations were used to investigate observed tendency. Elongation linker translates increase pitch helices, which allows achieving tuneable assemblies Au nanoparticles doped LC matrix. The impact helices chiral optical properties composites was investigated with full-wave based T-matrix method.
Chiral materials are essential to perceive photonic devices that control the helicity of light. However, chirality natural is rather weak, and relatively thick films needed for noticeable effects. To overcome this limitation, artificial were suggested affect chiral response in a much more substantial manner. Ideally, single layer such material, metasurface, should already be sufficient. While various structures fabricated with top-down nanofabrication technologies have been reported, here we...
Photonic nanostructures made of a dielectric sphere covered with many metallic nanospheres fabricated by self-assembly constitute basic building block for optical metamaterials magnetic response in the visible. However, they suffer from limited degrees freedom to tune their response. Once involved materials are chosen, is mostly determined. To overcome such limitation, we design, fabricate, and characterize here bottom-up metamaterial which nanorods used instead nanospheres. Nanorods offer...
Moiré effects arise from stacking periodic structures with a specific geometrical mismatch and promise unique possibilities. However, their full potential for photonic applications has yet to be explored. Here, we investigate the band structure an atomic stack of strongly coupled linear arrays in dipolar regime. A moiré parameter θ is used parameterize relative lattice constant between two that plays role 1D twist angle. The system’s interaction matrix analytically diagonalized reveals...
The differential response of chiral molecules to incident left- and right-handed circularly polarized light is used for sensing the handedness molecules. Currently, significant effort directed toward enhancing weak signals from molecules, with goal extending capabilities spectrometers lower molecular concentrations or small analyte volumes. Previously, optical cavities vibrational circular dichroism have been introduced. Their enhancements are mediated by helicity-preserving cavity modes...