Search Results (324)

This work presents results on laser-induced fabrication of metal and oxide structures on glass substrates. The Laser-Induced Reverse Transfer (LIRT) technique is applied using Zn and Sn, sintered ZnO and SnO₂, and oxide composite targets. The processing is performed by nanosecond pulses of a Nd:YAG laser system operated at wavelength of 1064 nm. Detailed analyses of the deposited material morphology, composition and structure are presented, as the role of the processing conditions is revealed. It is found that at the applied conditions of using up to five laser pulses, the deposited material is composed of a nanostructured film covered in microsized nanoparticle clusters or droplets. The use of metal targets leads to formation of structures composed of metal and oxide phases. The adhesion test shows that part of the deposited material is stably adhered to the substrate surface. It is demonstrated that the deposited materials can be used as resistive gas sensors with sensitivity to NH₃, CO, ethanol, acetone and N₂O, at concentrations of 30 ppm. The ability of the method to deposit composite structures that consist of a mixture of both investigated oxides is also demonstrated. Full article

Augmented reality (AR) near-eye displays (NEDs) couple microdisplay image light to the human eye via integrated optical modules, enabling seamless virtual–real fusion. As core components that synergistically transmit and diffract light, diffractive waveguides are promising for next-generation AR NEDs but face two bottlenecks: compromised full-color performance in single-layer structures caused by grating dispersion and lack of scalable fabrication technologies. To address these, we first propose a mass-production-compatible workflow based on deep ultraviolet (DUV) lithography for large-area nanostructured optics. This workflow enables high-precision wafer-level production with 200 mm wafers and nine dies per wafer, overcomes scalability issues, and is fully compatible with straight-configuration nanostructures to ensure manufacturing feasibility. Leveraging this workflow, we develop a single-layer diffractive waveguide system for AR NEDs, which comprises a thin glass substrate, a broadband high-efficiency multi-layer dielectric in-coupler, and a 2D out-coupler that concurrently expands and out-couples light. Rigorous coupled wave analysis (RCWA) optimized coupler diffraction, while ray tracing refined guided light intensity and significantly improved exit pupil uniformity. This work establishes a foundation for full-color, high-efficiency AR waveguides and provides a scalable paradigm for large-area nanostructured optical systems such as telescopes and lithography equipment. Full article

Bioactive glasses (BGs) are promising materials for enamel remineralization and caries management due to their ion-releasing ability and capacity to promote apatite formation. However, their clinical translation remains limited. Conventional BGs, such as 45S5, exhibit excellent bioactivity but are mechanically weak, prone to rapid ion burst release, and lack long-term stability. Recent advances—including secondary oxide incorporation (e.g., B₂O₃, ZnO), polymer–glass hybrids, and nanostructured systems like mesoporous BGs and RegeSi have improved reactivity, mechanical performance, and remineralization depth, though their durability under oral conditions is not yet established. BGs also display antibacterial activity by elevating local pH and releasing ions that inhibit cariogenic bacteria, but their broader ecological impact on the oral microbiome remains poorly understood. Emerging approaches such as halogen-modified BGs, particularly fluoride- and chloride-doped formulations, show dual benefits for remineralization and antimicrobial action, though supporting evidence is largely confined to in vitro studies. The absence of standardized protocols for assessing remineralization, ion release, and biofilm interaction further complicates cross-study comparisons and slows clinical adoption. Future progress will require interdisciplinary collaboration, standardized evaluation methods, and rigorous clinical validation to ensure that next-generation BGs can be safely and effectively integrated into dental practice. Full article

In this work, the plasmonic performance of SERS substrates fabricated by two methods was evaluated: the first method involves simultaneously reducing and depositing silver nanostars (AgNSs) onto copper hydroxide nanowires (Cu(OH)₂-NWs), and the second method involves dripping a pre-synthesized and concentrated solution of AgNSs onto the surface of the Cu(OH)₂-NWs. The distribution of AgNSs was characterized by SEM and compared with those deposited on glass after reaction times from 1 to 21 h. A more homogeneous AgNS distribution was observed on the nanowires. The SERS performance was evaluated using methylene blue (MB) as a probe molecule. The SERS intensity on substrates with Cu(OH)₂-NWs was 10 times better than the substrates with glass. Furthermore, the SERS intensity was tripled by dripping a more concentrated solution of AgNSs. This demonstrates that Cu(OH)₂-NWs significantly improve the homogeneity of SERS substrates by increasing the distribution of the metallic nanostructures. Full article

Ceramic materials have gained outstanding popularity in restorative and prosthetic dentistry due to their combination of high biocompatibility, mechanical durability, and natural esthetics. Among the most important developments in this field are the use of zirconia- and glass-based ceramics for various applications. Zirconia ceramics, especially yttria-stabilized tetragonal zirconia polycrystals (Y-TZP), are famous for their high mechanical strength, transformation toughening, chemical stability, and great biocompatibility. Newer generations like 4Y/5Y-PSZ zirconia have addressed the demand for higher translucency, meeting esthetic requirements. Glass–ceramics, including lithium disilicate and leucite-reinforced systems, are preferred for their optical properties, etchability, and strong adhesive bonding. Their microstructure provides a balance between strength and esthetics, supporting minimally invasive restorations with long-term clinical success. Both zirconia and glass–ceramics exhibit favorable biological responses, including low plaque accumulation and soft tissue compatibility. The goal of ongoing research is to overcome limitations, such as low-temperature degradation, bonding limitations, and surface durability. Also, to improve mechanical performance and functional integration, new approaches include 3D printing, graded materials, nanostructuring, and bioactive coatings. This review aims to provide a comprehensive overview of the composition, properties, clinical applications, current limitations, and future perspectives of zirconia- and glass-based ceramics in restorative dentistry. Full article

Enhancing the mechanical strength of transparent glass-ceramics (TGCs) without compromising their optical performance remains a key challenge for advanced optical and photonic materials. Among aluminosilicate systems, ZnO–MgO–Al₂O₃–SiO₂ (ZMAS) glasses are particularly attractive due to their ability to form ZnAl₂O₄-based nanostructures; however, their ion-exchange (IE) strengthening has not been systematically explored due to the absence of single-charged cations in their composition. In this study, a sodium-modified ZMAS glass was developed to enable efficient chemical strengthening while preserving glass-forming ability and optical clarity. Controlled two-stage heat treatment produced TGCs containing 5 mol% Na₂O, composed solely of ZnAl₂O₄ (gahnite) nanocrystals with an average size of 4–5 nm. The obtained TGCs showed a Vickers hardness of ~8.5 GPa, increasing to ~10–10.5 GPa after ion exchange in molten KNO₃ at 450 °C, without changes in phase composition or optical transmittance. Compared with literature data on alkali-containing TGCs, the developed material demonstrates a higher hardness level while maintaining full transparency. The results reveal a practical route toward chemically strengthened ZnAl₂O₄-based glass-ceramics combining optical clarity, high hardness, and damage tolerance for optical, photonic, and protective applications. Full article

Greenhouse horticulture is an energy-intensive production system that requires innovative solutions to reduce energy demand without compromising crop yield or quality. Functional greenhouse covers are particularly promising, as they regulate solar radiation while integrating energy-harvesting technologies. In this study, six nanostructured glass coatings incorporating semiconductor-based quantum dots (QDs) and quantum wires (QWs) of Ge and TiN are developed using magnetron sputtering—an industrially scalable technique widely applied in smart window and energy-efficient glass manufacturing. The coatings’ optical properties are characterized in the laboratory, and their agronomic performance is evaluated in greenhouse trials with lamb’s lettuce (Valerianella locusta) and radish (Raphanus sativus). Plant growth, yield, and leaf color (CIELAB parameters) are analyzed in relation to spectral transmission and the daily light integral (DLI). Although uncoated horticultural glass achieves the highest yields, several Ge-QD coatings provide favorable compromises by selectively absorbing non-photosynthetically active radiation (non-PAR) while maintaining acceptable crop performance. These results demonstrate that nanostructured coatings can simultaneously sustain crop growth and enable solar energy conversion, offering a practical pathway toward energy-efficient and climate-smart greenhouse systems. Full article

Background/Objectives: Nanotherapies are a strategy to combat Candida resistance. This study analyzed the impacts of iron oxide nanoparticles (IONPs) functionalized with a chitosan (CS) layer acting as carriers of chlorhexidine (CHX) on an oral candidiasis microcosm biofilm. Methods: Saliva samples from three healthy donors were used to form biofilms, to which Candida species were added to reproduce an oral candidiasis microcosm. Biofilms were cultivated for 72 h on glass coverslips using an active adhesion model. Biofilms without Candida served as a control model. The nanocarrier loaded with CHX at 78 (IONPs-CS-CHX78) or 156 µg/mL (IONPs-CS-CHX156) was co-incubated with the biofilms for 24 h. Controls included isolated IONPs, CS, and CHX, in addition to an untreated group (NC). Assays for biomass production, metabolism, microbial load, and lactic acid production were conducted to assess antibiofilm effects. Biofilm structure, viability, and thickness were also examined by confocal microscopy. Statistical analysis was performed using one-way ANOVA or Kruskal–Wallis, subsequently accompanied by the Student–Newman–Keuls post hoc test (p < 0.05). Results: CHX and IONPs-CS-CHX156 were the most effective agents against all tested biofilm models, significantly reducing metabolism, microbial load (bacterial and fungal), and viability. For the oral candidiasis biofilm, the nanocarrier did not affect biomass or biofilm thickness but led to a significant increase in lactic acid levels compared to NC. Conclusions: It is concluded that the nanocarrier of CHX exhibits a significant reducing effect on oral candidiasis microcosm biofilms at half the concentration required for non-carried CHX. This nanostructure can be explored in the development of antiseptic or disinfectant solutions for managing oral candidiasis. Full article

A cost-effective laser marker was employed to fabricate a superhydrophilic, photocatalytic Mg-Ti-based surface on glass under ambient conditions. The photocatalytic layer was first deposited via laser processing, followed by partial laser etching to generate micro/nanostructures on the surface. This method preserves partial photocatalytic functionality while enhancing surface roughness and introducing unique nanostructures, enabling the sample to simultaneously exhibit antifogging, self-cleaning capabilities, and high light transmittance. The optimal sample was achieved by tuning laser processing parameters, including repetition rate and scanning hatch distance. It maintained a water contact angle (WCA) of 0° after 15 days of outdoor exposure, which only increased to 21.2° after 30 days. In comparison, the WCA of reference glass increased from an initial 23.3° to 63.9° over the same period. Furthermore, the amount of dust accumulated on the optimal sample was significantly lower—by up to 43%—than that on the reference glass over one month under both indoor and outdoor conditions. After a single spray cleaning, the dust removal efficiency of the indoor-stored optimal sample reached 70%, which was 56% higher than that of the reference. For samples stored outdoors, a single spray removed 67% of the dust from the optimal surface, compared to only 26% for the reference, highlighting its excellent self-cleaning performance. Additionally, the optimal also showcased remarkable antifogging property, which had been maintained over the one-month exposure period without visible degradation. Moreover, the optimal sample exhibited a 2% enhancement in broadband light transmittance across the 400–1000 nm wavelength range, demonstrating strong potential for photovoltaic applications. The simultaneous achievement of antireflection, antifogging, and self-cleaning performance under both indoor and outdoor conditions over a one-month period has rarely been reported in the literature. Full article

Augmented reality (AR) displays are pivotal for delivering immersive experiences in the metaverse, thus driving significant research interest. Current AR systems, predominantly relying on diffraction principles, often suffer from low efficiency and face challenges in realizing monolithic full-color operation. Herein, we propose an AR system that integrates a broadband and highly efficient meta-grating in-coupler and an elliptical meta-grating out-coupler onto a single thin glass substrate. The meta-gratings, with unique nanostructures, enable coupling efficiency exceeding 60% for red (R), green (G), and blue (B) wavelengths across the entire field of view (FOV). Image-bearing light is first coupled into a single-layer optical waveguide via the meta-grating, then undergoes two-dimensional expansion through the elliptical meta-grating, and is ultimately coupled into the human eye to form a large AR FOV. Experimentally, we fabricated an optical waveguide prototype and validated the system’s high efficiency and color-enhanced imaging capabilities. This work advances the development of monolithic, trichromatic, highly efficient, and large FOV AR displays based on meta-grating technology. Full article

We present a systematic study on the fabrication of gold nanoislands by microwave-assisted annealing, a rapid and energy-efficient alternative to conventional thermal treatments. Gold thin films with nominal thicknesses of 4, 5, 6, 8, and 10 nm are deposited by thermal evaporation directly onto BK7 glass substrates, with and without a 3 nm chromium adhesion layer. The samples are subsequently annealed in a microwave kiln, where microwave irradiation is absorbed and converted to heat within the graphite-coated cavity (kiln), allowing the substrate temperature to exceed 550 °C, the threshold required for film dewetting. This process induces a controlled morphological evolution from continuous thin films to well-defined nanoislands, with the final size distribution strongly dependent on the initial film thickness. Compared with oven-based annealing, microwave treatment promotes faster and more uniform heating, which enhances atomic diffusion and accelerates dewetting while reducing the risk of substrate deformation or excessive coalescence. The resulting nanoislands exhibit tailored size-dependent plasmonic properties, with clear correlations between film thickness, crystallite size, and optical absorption features. Importantly, the method is cost-efficient, requiring shorter processing times and lower energy input, while enabling reproducible fabrication of high-quality plasmonic nanostructures on inexpensive glass substrates, suitable for applications in sensing, photonics, and nanophotonics. Full article

We present a novel approach for the synthesis of crystalline zinc oxide (ZnO) nanopowders based on the direct interaction of high-power microwave radiation with a zinc wire in atmospheric air. The process utilizes a localized microwave-induced plasma to rapidly vaporize the metal, followed by oxidation and condensation, resulting in the deposition of ZnO nanostructures on glass substrates. Plasma diagnostics confirmed the generation of a plasma in local thermodynamic equilibrium (LTE), characterized by high electron temperatures. Optical emission spectroscopy highlighted atomic species such as ZnI, ZnII, OI, OII, and NI, as well as molecular species including OH, N₂ and O₂. The spectral fingerprint of N₂ molecules reveals the presence of high energy electrons, while the persistent occurrence of OI and OII emission lines throughout the plasma spectrum reveals that ZnO formation is mainly driven by the continuous dissociation of molecular oxygen. High crystallinity and chemical purity of the synthesized ZnO nanoparticles were confirmed through SEM, TEM, XRD, FTIR, and EDX characterization. The resulting nanorods exhibit a rod-like morphology, with diameters ranging from 12 nm to 63 nm and lengths between 58 nm and 354 nm. This low-cost, high-yield method offers a scalable and efficient route for metal oxide nanomaterial fabrication via direct metal–microwave coupling, providing a promising alternative to conventional physical and chemical synthesis techniques. Full article

Ultrafast laser processing can produce micro/nanostructures, which is of great interest in advanced manufacturing. Ultrafast laser-induced events include non-equilibrium dynamic phenomena, occurring on the femtosecond to picosecond time scale and nanometer to micron space scale. Single-shot ultrafast imaging can provide multiple time-correlated evolution frames in one non-repeatable event with a temporal resolution of sub-picoseconds. However, previous approaches suffer from degraded spatial resolution, which is a bottleneck in microscopic imaging. For the spatial-frequency multiplexing methods based on structured illumination, a reconstruction strategy was proposed utilizing the frames’ conjugate symmetry in the Fourier domain. The spatial resolution is double that of the traditional algorithm by evaluating with synthetic data, revealing that the reconstruction resolution can reach the diffraction limitation. A two-frame microscopic system was constructed with a frame interval of 300 fs and a maximum spatial resolution of 1.4 μm. The interaction between a femtosecond laser and a fused silica glass plate was captured in a single shot and the dynamic evolution of the induced plasma was observed, verifying the application feasibility in ultrafast laser processing, providing experimental observations for interaction mechanism research and theoretical model optimization. Full article

In this study, we report the fabrication and multi-technique characterization of pure and rare-earth (RE)-doped ZnO thin films using nanostructured microclusters synthesized via electrospinning followed by calcination. Lanthanum (La), erbium (Er), and samarium (Sm) were each incorporated at five concentrations (0.1–5 at.%) into ZnO, and the resulting powders were drop-cast as thin films on glass substrates. This approach enables the transfer of pre-engineered nanoscale morphologies into the final thin-film architecture. The morphological analysis by scanning electron microscopy (SEM) revealed a predominance of spherical nanoparticles and nanorods, with distinct variations in size and aspect ratio depending on dopant type and concentration. X-ray diffraction (XRD) and Rietveld analysis confirmed the wurtzite ZnO structure with increasing evidence of secondary phase formation at high dopant levels (e.g., Er₂O₃, Sm₂O₃, and La(OH)₃). Raman spectroscopy showed peak shifts, broadening, and defect-related vibrational modes induced by RE incorporation, in agreement with the lattice strain and crystallinity variations observed in XRD. Elemental mapping (EDX) confirmed uniform dopant distribution. Optical transmittance exceeded 70% for all films, with Tauc analysis revealing slight bandgap narrowing (Eg = 2.93–2.97 eV) compared to pure ZnO. This study demonstrates that rare-earth doping via electrospun nanocluster precursors is a viable route to engineer ZnO thin films with tunable structural and optical properties. Despite current limitations in film-substrate adhesion, the method offers a promising pathway for future transparent optoelectronic, sensing, or UV detection applications, where further interface engineering could unlock their full potential. Full article

Glass inhomogeneities represent variations in the structural or compositional uniformity of glass, traditionally associated with process-related defects such as striae, bubbles, stones, and inclusions that impair transparency and mechanical stability. These “technological” inhomogeneities emerge during melting, forming, or annealing, and have long been the focus of industrial elimination strategies. However, recent developments in glass science and nanotechnology have reframed inhomogeneity as a potential asset. When precisely engineered at the nanoscale, inhomogeneities, such as nanocrystals, metal or semiconductor nanoparticles, and nanopores, can enhance glass with tailored optical and photonic functionalities, including upconversion luminescence, plasmonic response, nonlinear refractive behavior, and sensing capabilities. This entry provides an integrated perspective on the evolution of glass inhomogeneities, tracing the shift from defect suppression to functional nanostructuring. It discusses both the traditional classification and mitigation of detrimental defects, and the design principles enabling the intentional incorporation of beneficial nanoinhomogeneities, particularly in the context of optics and photonics. The utilization of engineered inhomogeneities in nuclear waste glasses is also discussed. Full article