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We have developed a powerful parallel genetic algorithm design tool for photonic crystal and waveguide structures. The tool employs a small-population-size genetic algorithm (microgenetic algorithm) for global optimization and a two-dimensional finite-difference time-domain method to rigorously design and optimize the performance of photonic devices. We discuss the implementation and performance of this design tool. We demonstrate its application to two photonic devices, a defect taper coupler to connect conventional waveguides and photonic crystal waveguides, and a sharp 90 degrees waveguide bend for low index contrast waveguides.
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http://dx.doi.org/10.1364/ol.28.002381 | DOI Listing |
ACS Nano
September 2025
Department of Biomedical Engineering, Tufts University, Medford, Massachusetts 02155, United States.
Achieving high performance nanoscale photonic functionalities remains extraordinarily challenging when using naturally derived biomaterials. The ability to manipulate ultrathin films of structural proteins─combined with photolithographic control of their polymorphism─unlocks a compelling route toward engineering biopolymer-based photonic crystals with precisely defined photonic bandgaps and reconfigurable structural colors. In this work, we describe a robust, water-based fabrication process for silk/inorganic hybrid one-dimensional (1D) photonic crystals that overcomes many of the conventional difficulties in ensuring reproducibility, uniformity, and reliability at the nanoscale.
View Article and Find Full Text PDFJ Am Chem Soc
September 2025
Department of Chemistry, Boston University, Boston, Massachusetts 02215, United States.
Two-dimensional (2D) materials offer a valuable platform for manipulating and studying chemical reactions at the atomic level, owing to the ease of controlling their microscopic structure at the nanometer scale. While extensive research has been conducted on the structure-dependent chemical activity of 2D materials, the influence of structural transformation during the reaction has remained largely unexplored. In this work, we report the layer-dependent chemical reactivity of MoS during a nitridation atomic substitution reaction and attribute it to the rearrangement of Mo atoms.
View Article and Find Full Text PDFAdv Sci (Weinh)
September 2025
Research Center for Crystal Materials, State Key Laboratory of Functional Materials and Devices for Special Environmental Conditions, Xinjiang Key Laboratory of Functional Crystal Materials, Xinjiang Technical Institute of Physics & Chemistry, Chinese Academy of Sciences, 40-1 South Beijing Road, Ur
Birefringent crystals are pivotal for modern optical modulation technologies, yet developing high-performance birefringent materials with large birefringence (Δn), wide bandgaps, and scalable synthesis remains a significant challenge. Different from the traditional planar [MQ] and distorted [MQ] (n ≥ 4) polyhedral units, a "linear-group" design strategy is proposed, targeting heavy-metal halides with [HgX] (X = halides) coordination modes to exploit their inherent polarizability anisotropy. Through systematic experimental investigations in the ternary A-Hg-X (A = Rb, Cs; X = Br, I) system, six novel Hg-based halides were synthesized.
View Article and Find Full Text PDFACS Omega
September 2025
Laboratório de Modelagem Molecular Aplicada e Simulação (LaMMAS), Universidade Estadual de Goiás, Anápolis, GO 75001-970, Brazil.
In this work, we report a theoretical investigation of the third-order nonlinear optical properties of the metronidazolium-picrate salt. The effects of the crystal environment are accounted for by the Iterative Charge Embedding approach, and the electronic calculations are carried out at the DFT (CAM-B3LYP/6-311++G-(d,p)) level. Furthermore, we use the results to parametrize a cavity Quantum Electrodynamics model for a quantum memory based on the Off-Resonant Cascaded Absorption protocol.
View Article and Find Full Text PDFAnal Chem
September 2025
Department of Analytical Chemistry, College of Chemistry, Jilin University, Changchun 130012, China.
Ginseng exosomes are a kind of promising extracellular vesicle containing unique bioactive components. However, the investigation on ginseng-derived exosomes is still in the initial stage. This study developed a photonic crystal-based Bragg scattering coupling electrochemiluminescence (BSC-ECL) biosensor for detection of miRNA396a-3p in exosome-like nanoparticles (GENs) and ginseng exosomes (Gexos).
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