Article
Materials Science, Multidisciplinary
Vladislav A. Chistyakov, Mikhail S. Sidorenko, Andrey D. Sayanskiy, Mikhail V. Rybin
Summary: Periodicity is commonly believed to be the main factor leading to the formation of band gaps. However, our analysis of three different structures with varying degrees of periodicity and ordering shows that this assumption may not be true. We compare a photonic crystal, a disordered lattice, and an ordered but nonperiodic quasicrystalline structure using a real-space metric, and find that the disordered lattice and the ordered quasicrystal belong to the same group of material structures. Despite their different degrees of periodicity, the photonic crystal and the quasicrystalline structure exhibit similar suppression of the density of states. Our findings provide new insights into the physical mechanisms responsible for the formation of band gaps.
Article
Engineering, Mechanical
Vaclav Houdek, Lubos Smolik, Zdenek Kubin
Summary: This article provides an experimental method for localizing an impact point in three-dimensional structures using a redundant sensor array. The method involves measuring the relative times of arrival of the travelling wave and estimating the times of arrival using continuous wavelet transform and optimal interval partitioning. The article also takes into account the varying wave speeds between the impact point and the measurement points, which reduces the accuracy of traditional triangulation and multilateration methods.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Longyan Gong
Summary: This article introduces a family of one-dimensional aperiodic tight-binding models with strong spatial correlations. Theoretical findings show that states are extended at resonance levels in certain positions. Numerical evidence is in excellent quantitative agreement with theoretical predictions.
Article
Engineering, Marine
Jiabin Liu, Anxin Guo, Hui Li
Summary: This study experimentally investigated the three-dimensional features of wind wave surface in a laboratory and obtained the dispersion law of wind waves. The Dynamic Mode Decomposition (DMD) was used to analyze the wave surface structure. The study provides important insights into the characteristics of wind waves.
Article
Multidisciplinary Sciences
Seok Kim, Jordan J. Handler, Young Tae Cho, George Barbastathis, Nicholas X. Fang
Summary: A new integral lithography method is proposed, utilizing a planar lens array to create digital light patterns to expand the printable area and achieve scalable 3D microstructure fabrication, surpassing the resolution-to-area scaling limit.
Editorial Material
Optics
Kosmas L. Tsakmakidis, Tomasz P. Stefanski
Summary: Topological features, particularly nodal rings, which usually require three-dimensional structures, have been experimentally demonstrated in a simple one-dimensional photonic crystal, representing a significant breakthrough.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Optics
Luca Dal Negro, Yuyao Chen, Sean Gorsky, Fabrizio Sgrignuoli
Summary: This paper proposes a new approach to enhance the efficiency of the two-photon spontaneous emission process through the multifractal optical mode density of photonic structures based on aperiodic distributions. The results demonstrate significantly enhanced emission rates by exciting highly resonant states across broadband multifractal spectra.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2021)
Article
Multidisciplinary Sciences
Gang Shi, Fan Gao, Zhilin Li, Rencong Zhang, Igor Gornyi, Dmitri Gutman, Yongqing Li
Summary: The study combines quantum interference, electron-electron interaction (EEI), and disorder to investigate the magnetotransport properties of topological insulators. It is found that magnetoconductance can be significantly enhanced by second-order interference and EEI effects, in contrast to systems with orthogonal symmetry. This study reveals important insights into the complex electronic processes in topological insulators through magnetoconductance analysis.
NATURE COMMUNICATIONS
(2023)
Article
Materials Science, Multidisciplinary
Hongzheng Zhao, Florian Mintert, Johannes Knolle, Roderich Moessner
Summary: This letter investigates the localization phenomenon in quantum systems under aperiodic drives. By identifying a hidden conservation law in a disordered spin chain, the authors find that the system can still exhibit localization even under aperiodic drives. Interestingly, the introduction of additional potential disorder leads to delocalization of the system, resulting in a controllable parametrically long-lived prethermal regime. This study provides an example of persistent single-particle localization without eigenstates.
Article
Nanoscience & Nanotechnology
Zizheng Wang, Hao Jiang, Guangfu Wu, Yi Li, Teng Zhang, Yi Zhang, Xueju Wang
Summary: This study reports a method for programmable three-dimensional microfluidic structures assembled from polydimethylsiloxane (PDMS) and shape-memory polymers (SMPs). The approach allows for the creation of diverse geometries and the ability to program temporary shapes, with well-maintained fluid flow during deformation and shape recovery.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Physics, Fluids & Plasmas
Zbigniew Walczak, Jaroslaw H. Bauer
Summary: Parrondo's effect, a well-known paradox in biased random walks, can not only occur in one-dimensional discrete quantum walks with regular coin sequences, but also with irregular coin sequences, affecting the quantum entanglement between the walker and the coin.
Article
Optics
Yuttana Intaravanne, Ruoxing Wang, Hammad Ahmed, Yang Ming, Yaqin Zheng, Zhang-Kai Zhou, Zhancheng Li, Shuqi Chen, Shuang Zhang, Xianzhong Chen
Summary: In this study, we propose and experimentally demonstrate a method for achieving color-selective three-dimensional (3D) polarization structures using a single metasurface. By controlling the incident wavelengths, different polarization structures can be achieved in the same observation region, providing polarization control with color information in 3D space.
LIGHT-SCIENCE & APPLICATIONS
(2022)
Article
Chemistry, Analytical
Zhenjie Qiao, Yongcun Yan, Sai Bi
Summary: This study successfully constructed a fluorescent/electrochemical dual-mode glucose biosensor based on three-dimensional DNA flowers-templated Ag nanoclusters (DFs/AgNCs), achieving sensitive and selective detection of glucose in human serums. The AgNCs in DFs can be etched by H2O2 generated from glucose oxidase catalysis, releasing Ag+ for signal-off fluorescent detection of glucose; furthermore, the liberated Ag+ induces conformation switch of Fc-DNA on Au electrode for signal-on electrochemical detection of glucose.
SENSORS AND ACTUATORS B-CHEMICAL
(2022)
Article
Optics
Mahmut Bagci
Summary: The dynamics of two-dimensional Pythagorean lattice solitons in quadratic nonlinear media are explored, showing the existence of periodic and aperiodic lattice solitons and determining the stability domain for all parameters in the model. It is found that stable solitons can exist in both periodic and aperiodic lattices, and the decay of unstable solitons can be prevented by adjusting the potential depth and propagation constant.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2021)
Article
Optics
Jadranka M. Vasiljevi, Alessandro Zannotti, Dejan Timotijevi, Cornelia Denz, Dragana M. Jovid Savid
Summary: In this study, we introduced randomness into a complex optical system and measured its contribution to understand the relationship between randomness and complexity. The experimental results showed that increased randomness enhances light transport, with diffusive-like transport observed at lower disorder degrees and Anderson localization detected at the range of highest light transport.
Article
Optics
Christina Joerg, Sachin Vaidya, Jiho Noh, Alexander Cerjan, Shyam Augustine, Georg von Freymann, Mikael C. Rechtsman
Summary: Weyl points are point degeneracies in the momentum space of 3D periodic materials, associated with a quantized topological charge. This study experimentally observed the splitting of a quadratic Weyl point into two linear Weyl points in a 3D micro-printed photonic crystal. The theoretical analysis showed that this splitting occurs along high-symmetry directions in the Brillouin zone, which is important for the development of robust topological devices in the near-infrared.
LASER & PHOTONICS REVIEWS
(2022)
Article
Optics
J. Schulz, C. Joerg, G. von Freymann
Summary: This study experimentally demonstrates that the next-nearest-neighbor coupling in a waveguide array can be naturally negative. By fabricating dielectric zig-zag shaped waveguide arrays and adjusting the angle of the zig-zag shape, it is possible to tune the coupling ratios between positive and negative values, as well as reduce the impact of the coupling to zero at certain angles. The existence of negative couplings is confirmed experimentally and the improved accuracy of a refined tight-binding model is shown. These findings are also important for studying other discrete systems where the tight-binding model is commonly used.
Article
Optics
Bjoern Haase, Mirco Kutas, Felix Riexinger, Patricia Bickert, Andreas Keil, Daniel Molter, Michael Bortz, Georg von Freymann
Summary: This erratum corrects two typing errors in a previously published manuscript, which were limited to theoretical derivation and did not affect numerical calculations, results, or conclusions.
Article
Optics
Tobias Pfeiffer, Jens Klier, Georg von Freymann, Daniel Molter
Summary: Nonlinear frequency conversion provides an elegant method for detecting low-energy photons with different wavelengths from the pump wavelength while providing phase information. We propose a phase-sensitive measurement method in the terahertz spectral range using visible light, which enables fast determination of layer thicknesses and achieves phase-resolved detection of terahertz pulses with standard equipment.
Article
Chemistry, Multidisciplinary
Daniel Molter, Kim-Sophie Ellenberger, Jens Klier, Stefan Duran, Joachim Jonuscheit, Georg von Freymann, Nico Vieweg, Anselm Deninger
Summary: The acquisition speed of terahertz time-domain spectroscopy systems has been significantly improved in recent years, making waveform acquisition rates in the kilohertz range feasible. This study presents measurements of sub-wavelength layers in multilayer systems at a rate of 1.6 kHz, allowing real-time analysis of individual layer thicknesses. By combining rotation of the samples with linear translation of the measurement head, the measurement yield is maximized. The ECOPS system, with its single-shot dynamic range of 40 dB and bandwidth above 3 THz, achieves sub-micron repeatability for each layer.
APPLIED SCIENCES-BASEL
(2022)
Article
Optics
Nicolas Lang, Sven Enns, Julian Hering, Georg von Freymann
Summary: This study presents a simple, fast, and easily implementable algorithm for predicting the final structure topography in multi-photon lithography. The algorithm approximates the three main steps of lithography and shows promising results in agreement with experimental observations. The use of a Downhill-Simplex algorithm for parameter optimization significantly reduces deviations and enables the production of highly conformal and high-quality microstructures.
Article
Materials Science, Multidisciplinary
Ruben C. R. Pompe, Dominic T. Meiers, Walter Pfeiffer, Georg von Freymann
Summary: This study presents a method for identifying different coherent light transport mechanisms using time and spatially resolved coherent light scattering spectroscopy. The results show that about 20% of the scattered light in ultrathin brilliant scattering media originates from weakly localized random photonic modes, rather than solely diffusive light transport.
ADVANCED OPTICAL MATERIALS
(2022)
Correction
Optics
Nicolas Lang, Sven Enns, Julian Hering, Georg Von Freymann
Article
Optics
Bjorn Erik Haase, Joshua Hennig, Mirco Kutas, Erik Waller, Julian Hering, Georg von Freymann, Daniel Molter
Summary: Sensing with undetected photons in the infrared region is achieved through polarization-optics-based phase-quadrature implementation in a nonlinear interferometer. This allows for obtaining phase and visibility information with a single image acquisition without the need for phase variation, enabling the detection of dynamic processes. The method is demonstrated on both static and dynamic measurement tasks, showcasing its effectiveness.
Article
Optics
Felix Paries, Oliver Boidol, Georg von Freymann, Daniel Molter
Summary: This study aims to improve the performance of terahertz time-domain spectroscopy systems by reducing timing errors in electronic phase detection. The results show a significant improvement in both terahertz bandwidth and signal-to-noise ratio, leading to a more accurate measurement of multi-layer thickness.
Article
Materials Science, Multidisciplinary
Dominic T. Meiers, Maximilian Rothammer, Maximilian Maier, Cordt Zollfrank, Georg von Freymann
Summary: The great flexibility of direct laser writing (DLW) comes from the ability to fabricate precise 3D structures in small scales and the wide range of applicable materials. This study reports a new bio-sourced resist using chitin as the monomeric unit, paving the way for non-hydrogel resists. It is also shown that using two photoinitiators is more advantageous than using a single one, where the first one acts as a sensitizer and transfers energy to the second one for initiating polymerization.
ADVANCED ENGINEERING MATERIALS
(2023)
Editorial Material
Optics
C. O. R. D. T. Zollfrank, H. U. Cao, G. E. O. R. G. VON Freymann, P. A. R. I. N. D. A. Vasa, Helge-otto Fabritius, A. R. T. Agrawal
Summary: Tailored disorder is an emerging design concept that explores the photonic properties of material composites with deliberately introduced irregularities. This rapidly developing field combines inspiration from biology, physics, and chemistry to create advanced photonic materials with interesting properties.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Optics
Maximilian Rothammer, Dominic T. Meiers, Maximilian Maier, Georg Von Freymann, Cordt Zollfrank
Summary: Novel bifunctional cellulose diacetate derivatives were synthesized for bio-based photoresists that can be structured by two-photon absorption via direct laser writing (DLW) without the need for a photoinitiator. Thiol moieties and olefinic or methacrylic side groups were functionalized on cellulose diacetate to achieve thiol-conjugated cross-linking. These cellulose derivatives can also be photo-cross-linkable via UV irradiation (λ = 254 nm and 365 nm) without using an initiator.
JOURNAL OF THE OPTICAL SOCIETY OF AMERICA B-OPTICAL PHYSICS
(2023)
Article
Instruments & Instrumentation
Matthias R. Schweizer, Franziska Kuehn, Malte Koster, Georg von Freymann, Burkard Hillebrands, Alexander A. Serga
Summary: Temperature variations can be used to create reconfigurable spatial structures in physical and biological objects. This paper presents an experimental optical setup for creating tunable two-dimensional temperature patterns on a micrometer scale, and demonstrates its practical application in the production of temperature-induced magnetization landscapes in ferrimagnetic yttrium iron garnet films.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Computer Science, Information Systems
Karl H. May, Andreas Keil, Georg Von Freymann, Fabian Friederich
Summary: Terahertz tomography is a non-contact inspection technique that reconstructs 3D volume of objects by imaging them from multiple angles and using intensity and time-of-flight transmission data. Diffraction and refraction limitations of terahertz radiation are addressed by applying ray tracing and prior knowledge of the sample to predict beam paths. Two reconstruction methods are presented, one filters out strongly deviating beams to remove artifacts, and the other employs off-axis measurements to detect strongly deflected beams and enhance image quality.