Search

We demonstrate a sensitive optically pumped magnetometer using rubidium vapor and 0.75 amg of nitrogen buffer gas in a sub-mm-width sensing channel excavated by femtosecond laser writing followed by chemical etching. The channel is buried less than 1 mm below the surface of its fused silica host material, which also includes reservoir chambers and micro-strainer connections, to preserve a clean optical environment. Using a zero-field-resonance magnetometry strategy and a sensing volume of 2.25 mm 3 , we demonstrate a sensitivity of ≈ 1 pT / Hz at 10 Hz. The device can be integrated with photonic structures and microfluidic channels with 3D versatility. Its sensitivity, bandwidth, and stand-off distance will enable detection of localized fields from magnetic nanoparticles and μ L NMR samples. [ABSTRACT FROM AUTHOR]

The formation of laser-induced periodic surface structures (LIPSSs) on fused silica upon irradiation with plane wave, double pulse, spot processing, and scanning processing (pulse duration tp = 35 fs, center wavelength λ = 800 nm, low repetition rate ≈1 kHz) is studied theoretically with an improved three-dimensional finite-difference time-domain plasma model. The model covers both intrapulse feedback under single shot and interpulse feedback under multi-shots, thus enabling better prediction of transient responses during laser–material interaction and the evolution of the ablated morphology and accumulated defects' density with more shots. In simulations of a single plane wave, a double pulse can modulate LIPSS periodicity. In simulations of spot processing with Gaussian beam, an increase in the number of shots results in a noticeable ablation pattern where high-spatial-frequency LIPSS surrounds low-spatial-frequency LIPSS at a fluence of 2.8 J/cm2. Moreover, simulations of scanning processing with Gaussian beam showcase the broad applicability of this model, revealing that the orientation of the LIPSS depends on the polarization direction rather than the scanning path. This new model provides a powerful tool to simulate the formation of LIPSS on silica, particularly when temporally modulated laser is involved or predicting the evolution of morphology dependent on the number of shots. [ABSTRACT FROM AUTHOR]

Ultrafast laser technology presents the unique capacity to process glass materials with an outstanding processing quality; however, combining high quality and high throughput is still a crucial issue because glass is brittle and highly heat sensitive. One strategy to overcome this limitation is to split in space the main laser beam into multiple beams for process parallelization. In the present paper, the simultaneous interaction of several femtosecond laser beams at the surface of fused silica targets is addressed experimentally and theoretically. This work is devoted to highlight the beams cooperation for inducing stress in the material. The experiment consists in irradiating the target with multiple laser pulses with a wavelength of 1030 nm and a duration of 500 fs. The induced stress is observed through post-mortem cross-polarized microscopy. A multiscale and multiphysics model describing laser energy deposition into the material and its mechanical response is developed. The influence of various laser parameters is studied: number and position of laser beams, repetition rate, and fluence. Both experimental and modeling results, which are in a good agreement, show significant cooperative effects for stress formation with large enough laser energy deposition, possibly leading to detrimental cracks. [ABSTRACT FROM AUTHOR]

Thermally stimulated discharge (TSD) technique is a traditional method in dielectric research, especially for electrets. However, in conventional open-circuit and short-circuit TSD techniques, it is difficult to distinguish the surface charge and body charge of dielectric materials. In particular with the test of polymer electrets, the deformation of the polymer film may take place during the measurement process, which will affect the accuracy of the experiment results. In this paper, a glass-assisting TSD (GA-TSD) technique is proposed to solve the above problems. The feasibility of the experimental technique is verified with the GA-TSD spectra of fluorinated ethylene-propylene copolymer electret films. In addition, their theory analysis is also accomplished. The influences of glass thickness, glass dielectric property, and metallizing on the glass on GA-TSD spectra are investigated. The results prove that the GA-TSD spectra can clearly distinguish the difference between surface charge and body charge according to the current direction. The quartz glass with the lowest dielectric constant is best suitable for the GA-TSD technique. The influence of the glass thickness and metallizing on the glass on GA-TSD spectra is little. [ABSTRACT FROM AUTHOR]

High-pressure treatment of oxide glasses can lead to significant alteration of various material properties such as increased density, ductility, and elastic moduli. In this study, a model of melt-quenched bulk silica glass was subject to high-pressure treatments (up to 16 GPa) using molecular dynamics simulations. The thermal conductivity of such prepared glass structures was determined using the equilibrium Green–Kubo method. We observed that, up to the pressure treatments of ∼ 6 GPa, the structure exhibits moderate density increase and a much steeper increase between 6 and 16 GPa, with associated density increase of fivefold silicon atoms. We also observed a noticeable increase (up to 20%) of the thermal conductivity in samples subjected to high-pressure treatments. The observed increases are somewhat, but not significantly, larger than those predicted by the minimum thermal conductivity model, accounting for density and elastic moduli increase. [ABSTRACT FROM AUTHOR]

We report the development of a novel variant of cavity ringdown polarimetry using a continuous-wave laser operating at 532 nm for highly precise chiroptical activity and magnetometry measurements. The key methodology of the apparatus relies upon the external modulation of the laser frequency at the frequency splitting between non-degenerate left- and right-circularly polarized cavity modes. The method is demonstrated by the evaluation of the Verdet constants of crystalline CeF3 and fused silica, in addition to the observation of gas- and solution-phase optical rotations of selected chiral molecules. Specifically, optical rotations of (i) vapors of α-pinene and R-(+)-limonene, (ii) mutarotating D-glucose in water, and (iii) acidified L-histidine solutions are determined. The detection sensitivities for the gas- and solution-phase chiral activity measurements are ∼ 30 and ∼ 120 μdeg over a 30 s detection period per cavity round trip pass, respectively. Furthermore, the measured optical rotations for R-(+)-limonene are compared with computations performed using the TURBOMOLE quantum chemistry package. The experimentally observed optically rotatory dispersion of this cyclic monoterpene was thus rationalized via a consideration of its room temperature conformer distribution as determined by the aforementioned single-point energy calculations. [ABSTRACT FROM AUTHOR]

Cerium oxide (CeO 2) is a primary abrasive frequently used in quartz glass polishing slurry for facilitating glass surface planarisation. However, due to its exorbitant synthesis costs and extremely corrosive as well as toxic reagents in the system, the chemical modification of CeO 2 abrasives have limited practical applications. In this work, a novel chemical mechanical polishing slurry for quartz glass incorporating potassium oleate (KOL), deionised water (DIW), cerium dioxide and molybdenum disulphide (MoS 2) was developed in this paper to enhance the chemical mechanical polishing (CMP) performance of CeO 2 -based polishing slurry. KOL creates an alkaline environment for the system, further develops silicate insoluble substances on the quartz glass surface and boosts the material removal rate (MRR) in CMP. MoS 2 exhibits a two-dimensional layered nanosheet structure between the abrasive and quartz glass, and then acts as a solid lubricant to prevent excessive mechanical damage, thus increasing the abrasive's wettability. This characteristic helps avoid scratches and other defects on the quartz glass surface. Notably, when the content of KOL and MoS 2 in the system is 0.2 wt% and 0.3 wt%, respectively, the surface roughness of the quartz glass surface is 0.48 nm under the scanning area of 15 × 15 μm2 and the MRR is 24.03 μm/h following CMP. The synergistic interaction between CeO 2 and MoS 2 significantly enhances the abrasive performance on the glass substrate, offering a novel approach for developing polishing fluids that leverage the collaborative effects between abrasives and two-dimensional materials. [ABSTRACT FROM AUTHOR]

Fused quartz exhibits excellent optical and mechanical properties. Achieving ultra-smooth polishing of fused quartz is of great significance. Nanoparticle jet polishing (NJP) utilizes the synergistic effects of physics and chemistry to achieve damage-free atomic-level material removal. However, the influence of the process parameters on the interaction between the polishing particle and the workpiece remains unclear. This study experimentally and theoretically explored the effects of the slurry concentration, temperature, and pH on material removal. A high volume fraction of polishing slurry leads to poor fluidity of the polishing slurry and poor wettability on fused quartz, which slows down the growth rate of material removal rate. The polishing environment temperature regulates the material removal rate by altering the Ce3+ content in the polishing slurry. The pH influences the material removal process by affecting the Ce3+ content and the adsorption state between the particles and the workpiece. Alkaline conditions are conducive to forming stable ≡Ce-O-Si ≡ chemical bond to improve the material removal rate. Conversely, the electrostatic force between particle and workpiece in strongly acidic and alkaline environment hinders chemical adsorption. This study contributes to the understanding of the material removal process in NJP, providing a theoretical basis for optimizing the polishing process and improving the material removal rate. [ABSTRACT FROM AUTHOR]

To develop a high-temperature-resistant adhesive specifically for quartz glass, several groups of aluminum phosphate-based adhesives with different P/Al ratios and Si/B 4 C ratios were prepared, and the bonding performance and mechanism were systematically analyzed. Adding Si and B 4 C affected the decomposition process of phosphates, mainly in terms of the types of decomposition products and the crystal transformation of phosphates. Their addition avoided the generation of metaphosphate and improved the component stability of the adhesive matrix. The oxidation of Si and B 4 C brought about considerable quality compensation, which was crucial for maintaining the structural integrity of the adhesive layer. Besides, the oxidation products further reacted with the adhesive and quartz substrate to form ceramic or glass phases, significantly improving the bonding performance. When the P/Al ratio and Si/B 4 C ratio were 2:3 and 10:3, APSB adhesive presented the best performance. After curing at room temperature or pre-treatment at 1200 °C, the bonding strength reached 16.3 MPa and 14.6 MPa, respectively. After pre-treatment at 1200 °C, APSB could provide above 6 MPa in extreme environments with the range of RT∼1200 °C. The thermal shock resistance of APSB was superior to its thermal cycling resistance. After 10 thermal shocks at 600 °C, 800 °C, and 1000 °C, the bonding strength of APSB is 4.52 MPa, 4.33 MPa, and 7.33 MPa, respectively. Nevertheless, the CTE of APSB adhesive after sintering remained stable at 5.4 × 10−6 K−1, which was still significantly different from the CTE (0.5 × 10−6 K−1) of quartz glass. Therefore, there is great potential for developing low-expansion adhesives in the near future. [ABSTRACT FROM AUTHOR]

Caesium tungsten bronze materials are widely used in various applications, such as architectural glass, medicine, insulation coating and textile fibre, owing to their excellent mechanical, optical and thermal properties. In this study, a caesium tungsten bronze (Cs x WO 3 , x = 0.3–0.32) target with a relative density of 99.63 % and uniform microstructure was successfully prepared via hot-pressing sintering. Cs x WO 3 films were deposited on a quartz glass substrate via magnetron sputtering, and the mechanisms and effects of the substrate temperature and oxygen flow rate on the phase structure, microstructure and optical properties of Cs x WO 3 films were investigated. When the substrate temperature increased, the crystallinity and oxygen vacancy concentration of the Cs x WO 3 film improved. Consequently, the visible light transmittance of the film decreased, whereas the infrared blocking rate considerably increased, reaching up to 93.877 %. With the increase in the oxygen flow rate, the visible light transmittance exhibited an increasing trend, reaching a maximum value of 84.319 %, whereas the infrared blocking rate remained relatively stable. We successfully fabricated Cs x WO 3 films possessing a visible light transmittance of 66 % and infrared blocking rate of 94.97 % under the conditions of a substrate temperature of 300 °C and an oxygen flow rate of 2.5 sccm. Our study offers a method for the large-scale production of Cs x WO 3 films, which are excellent infrared shielding materials, rendering a substantial contribution to global energy conservation and emission reduction. [ABSTRACT FROM AUTHOR]

Fused silica is a material of great importance in the field of precision optical equipment due to its excellent optical properties, e.g. photolithography, laser fusion devices, etc. However, the material's inherent hardness and brittleness render it a challenging material to process. Therefore, an enhanced precision lapping technique was proposed, i.e., a synergistic integration of mechanical and mechanochemical lapping processes. Firstly, a synergistic lapping tool with an outer layer of porous diamond abrasive and an inner layer of CeO 2 abrasive was fabricated by hot press forming method. The reduction of layer thickness due to abrasion and detachment of the porous diamond abrasive layer was analyzed, and the lapping mechanism of porous diamond on fused silica materials was revealed. The surface creation mechanism of the CeO 2 abrasive layer on fused silica material was analyzed by molecular dynamics simulation and the results were validated by enhanced precision lapping experiment. The results demonstrated that the surface atoms of fused silica are removed in a 'remote disordered' manner by conventional diamond abrasive grains, whereas the surface atoms of fused silica are removed in a 'proximally ordered' manner by the fine porous diamond abrasive grains through the micro-multi-flute cutting. Consequently, the grinding of a porous diamond abrasive layer can significantly reduce the processing damage, with the surface roughness of the lapping Ra reaching 199 nm. The lapping of CeO 2 induces the formation of an oxygen bridge on the surface of fused silica, which then produces bending vibration. This is followed by the adsorption and diffusion of oxygen atoms, which form the -Ce-O-Si intermediate with the oxygen atoms shared with the fused silica. This process results in the formation of CeSiO 3 and CaSiO 3 compounds. The final surface quality with a surface roughness of Ra 21 nm was obtained by mechanochemical lapping of the cerium oxide abrasive layer. The single mechanical-mechanochemical composite ultra-precision lapping process provides technical support for the efficient and low-damage processing of hard and brittle components. [ABSTRACT FROM AUTHOR]

Laser glass deposition is an additive manufacturing method to produce individualized glass components. This process uses a CO2 laser with a defocused beam as a heat source to additively melt-fused silica filaments. The fiber filament is fed laterally in the process zone and is deposited layer-by-layer to form 3D structures. The formation of boundary layers in conventional 3D-printing methods is a usual byproduct of the process. In this paper, the boundary layer formation of deposited fused silica filaments is investigated in detail by means of varying different process parameters such as, laser power, feed rate, laser spot diameter, and printing strategy. This involves examining both thin-walled and thick-walled test specimens. Quality characteristics like the surface roughness and the optical transmission are analyzed for the printed specimen. Finally, fully transparent structures with surface roughness below 100 nm and a transparency of 90% could be printed boundary layer-free and without post-processing. [ABSTRACT FROM AUTHOR]

ABSTRACT A considerable number of different tools and operating materials are used in classical optics manufacturing. Moreover, further parameters such as environmental and process conditions contribute to material removal and surface smoothing in the course of production. A large potential variety of the final surface state of optics can thus be expected. Against this background, nominally identical fused silica optics surfaces purchased from different suppliers were investigated in the present work via x‐ray photoelectron spectroscopy, laser‐induced breakdown spectroscopy, infrared spectroscopy, ellipsometry, and atomic force microscopy. It is shown that the surfaces under consideration feature quite different types and degrees of contamination that can be attributed to the particularly used water and polishing agent. Moreover, slight differences in index of refraction and surface roughness were detected. The presented data thus confirm the expectation that the surface state of an optical component might depend on its origin. The findings are intended to sensitize users regarding such a potential impact, for example, when switching to other suppliers for bought‐in parts and outsourced precision optics items. [ABSTRACT FROM AUTHOR]

Fused-silica-based microlens array (MLA) has excellent stability in the harsh environment. However, it is still a challenge to efficiently prepare superhydrophobic quasi-periodic MLA and keep the optical performance of the microlens. In this paper, we proposed spatial modulated picosecond laser parallel processing method to prepare a superhydrophobic quasi-periodic MLA on fused silica. By using a spatial light modulator, the picosecond laser was shaped to multi-focal spots and line-shape beam, respectively, which improved the fabrication efficiency. The line-shape beam was the key to induce micro-nanostructures on the smooth MLA and keep the optical performance of the microlens. The results showed that the surface roughness of the microlens region was less than 100 nm. Combing with shaping picosecond laser processing and chemical treatment, the superhydrophobic MLAs showed the excellent anti-fogging and self-cleaning properties. The average contact angle of the superhydrophobic MLAs was 162.3°. The superhydrophobic MLA showed low adhesion to water droplet (<10 μN) and low contact angle hysteresis (2.1° ± 0.7°). We believe shaping picosecond laser parallel processing method is a flexible and low-cost approach to prepare superhydrophobic micro-optical elements on fused silica. [ABSTRACT FROM AUTHOR]

Terahertz (THz) radiation sources based on two‐color femtosecond plasmas in air are becoming a mature technology for coherent spectroscopy and strong‐field physics across the extended THz range to several tens of THz. The field‐resolved detection of such THz transients relies on the third‐order nonlinearity of the detection medium. Here, a comparative measurement is demonstrated with air‐biased coherent detection (ABCD) and solid‐state biased detection (SSBCD) as a novel method to measure the dispersion of the magnitude and phase of the relevant third‐order nonlinearity χ(3)(2ω±Ω;ω,ω,±Ω)$\chi ^{(3)}(2\omega \pm \Omega;\omega,\omega,\pm \Omega)$ for fused silica (SiO2${\rm SiO}_2$) and silicon nitride (SiN). Based on the development of the ultrabroadband SSBCD device with a detection bandwidth exceeding 30 THz, χ(3)$\chi ^{(3)}$ measurements are obtained across the 1–28 THz frequency range, hence covering the THz and far‐infrared. It is shown that the vibrational modes in SiO2${\rm SiO}_2$ and SiN in the THz range lead to strong resonant enhancement and dispersion of the nonlinearity. The SSBCD devices operate down to nanojoule (nJ) probe energy, and their is demonstrated by measuring the dielectric function of the Lorentzian line profile of transverse‐optical (TO) phonon mode at 9 THz in single‐crystal gallium arsenide (GaAs) and observing the weak phonon combination bands near the TO phonon. [ABSTRACT FROM AUTHOR]

Stable electrospray generation from fused silica tips is critical for mass spectrometry, but these tips can degrade, leading to droplet formation and poor spray. A quick, cost-effective method has been developed to rejuvenate these tips, extending their usability and reducing expenses. The protocol involves sequentially rinsing pulled fused silica emitters for electrospray ionization (ESI) with acetone, water, an aqueous sodium hydroxide solution, water, and acetone again, followed by air drying. Next, the tip is dipped into a hydroxy-terminated polydimethylsiloxane solution and air dried. A final acetone rinse completes the process, which does not require disassembling the fluidic flow system or removing the nESI tip from its mount. This reconditioning not only prevents droplet formation but also restores the correct spray pattern, ensuring stable electrospray for 1–2 weeks. Tips can undergo multiple reconditionings. Although the protocol may lead to transient contaminant peaks, these diminish over 24 hours, and a list of potential contaminants is provided. [ABSTRACT FROM AUTHOR]

Silica polymorphs occur under various pressures and temperature conditions, and their characteristics can be used to better understand the complex metamorphic history of planetary materials. Here, we conducted isothermal heating experiments of silica polymorphs in basaltic eucrites to assess their formation and stability. We revealed that each silica polymorph exhibits different metamorphic responses: (1) Quartz recrystallizes into cristobalite when heated at ≥ 1040 °C. (2) Monoclinic (MC) tridymite recrystallizes into no other polymorphs when heated at ≤ 1070 °C. (3) Silica glass recrystallizes into quartz when heated at 900–1010 °C, and recrystallize into cristobalite when heated at ≥ 1040 °C. These results suggest that MC tridymite in eucrites does not recrystallize into other polymorphs during the reheating events, nor does it recrystallize from other silica phases below the solidus temperature of eucrite (~ 1060 °C). Additionally, we found that pseudo-orthorhombic (PO) tridymite crystallizes from quenched melts in the samples heated at ≥ 1070 °C. Previously, cristobalite has been considered as the initial silica phase, which crystallizes from eucritic magma. Our findings suggest that the first crystallizing silica minerals may not always be cristobalite. These require a reconsideration of the formation process of silica minerals in eucrites. [ABSTRACT FROM AUTHOR]

Poly(dimethylsiloxane) (PDMS) has emerged as a promising polymer for fabricating optical waveguides. Its optical transparency, stretchability, flexibility, biocompatibility, and facile processing are a complement to common optical materials that are more brittle and stiff such as fused silica, polystyrene (PS), and poly(methyl methacrylate) (PMMA). Although PDMS is not a new material, with its first synthesis dating back to the early twentieth century, recent decades have seen an increased effort to expand its use in optical waveguides beyond conventional rubber applications. This review compiles established concepts and new advancements in PDMS science to shed light on limitations and new opportunities to better harness PDMS’ potential for optical waveguiding. With the materials science tetrahedron in mind (structure, properties, processing, and performance), this review explores the state‐of‐the‐art in PDMS waveguide technology and exposes relevant basic concepts pertaining to its physicochemical properties. The goal is to equip the photonics community with knowledge to further expand PDMS waveguide technology. The review covers three main topics: PDMS’ key properties (chemical, optical, thermal, and mechanical, besides biological and environmental aspects); PDMS waveguide fabrication techniques (processing, refractive index tuning, and post‐processing); and its applications. The review concludes with a discussion of current challenges and future prospects. [ABSTRACT FROM AUTHOR]

This study evaluates Algerian kaolin (Djebel Debbagh (DD1) and Tamazart (KT2)) as potential substitutes for commercial kaolin (Lab) in the production of mullite‐based ceramics. Three compositions were prepared by incorporating the appropriate percentage of alumina to each calcined kaolin to achieve stoichiometric mullite precursors. The phase evolution of individual kaolin powders, as well as their mixtures with alumina, depends strongly on the calcination temperature and kaolin impurities. The differential scanning calorimetry combined with thermogravimetric analysis (TGA) showed lower secondary mullite formation temperature for the KT2‐based mixture. However, X‐ray diffraction revealed a complete mullitization in DD1 mixture. The K2O hindered cristobalite formation and reduced secondary mullite formation rate. Microstructure analysis showed lath‐shaped primary mullite and equi‐axed secondary mullite particles. After sintering at 1600°C, The KT2‐based sample (M3) exhibited higher density (3.013 g/cm3) and hardness (9.9 GPa), whereas the DD2‐based sample (M2) showed moderate densification (2.91 g/cm3) and higher flexural strength (159.42 MPa). Impurities (mainly Fe2O3, and K2O) promoted liquid phase sintering, resulting in greater densification in M3, whereas M2 showed more homogeneous microstructure, refined grains, and lower glassy phase content, contributing to enhanced strength. [ABSTRACT FROM AUTHOR]

Background: Neutron beams utilized for performing BNCT are composed of a mixture of neutrons and gamma rays. Although much of the dose delivered to the cancer cells comes from the high LET particles produced by the boron neutron capture reaction, the dose delivered to the healthy tissues from unwanted gamma rays cannot be ignored. With the increase in the number of accelerators for BNCT, a detector system that is capable of measuring gamma ray dose in a mixed neutron/gamma irradiation field is crucial. Currently, BeO TLDs encased in quartz glass are used to measure gamma ray dose in a BNCT irradiation field. However, this type of TLD is no longer commercially available. A replacement dosimetry system is required to perform the recommended ongoing quality assurance of gamma ray measurement for a clinical BNCT system. Purpose: The purpose of this study is to evaluate the characteristics of a BeO OSLD detector system under a mixed neutron and gamma ray irradiation field and to assess the suitability of the system for routine quality assurance measurements of an accelerator‐based BNCT facility. Methods: The myOSLD system by RadPro International GmbH was evaluated using the accelerator‐based neutron source designed for clinical BNCT (NeuCure BNCT system). The readout constancy, linearity, dose rate effect, and fading effect of the OSLD were evaluated. Free‐in‐air and water phantom measurements were performed and compared with the TLD results and Monte Carlo simulation results. The PHITS Monte Carlo code was used for this study. Results: The readout constancy was found to be stable over a month‐long period and similar to the TLD results. The OSLD readout signal was found to be linear, with a high coefficient of determination (R2 ≥ 0.999) up to a proton charge of 3.6 C. There was no significant signal fading or dose rate dependency. The central axis depth dose and off‐axis dose profile measurements agreed with both the TLD and Monte Carlo simulation results, within one standard deviation. Conclusion: The myOSLD system was characterized using an accelerator system designed for clinical BNCT. The experimental measurements confirmed the OSLD achieved similar, if not superior to, the currently utilized dosimetry system for routine QA of an accelerator‐based BNCT system. The OSLD system would be a suitable replacement for the current TLD system for performing routine QA of gamma ray dose measurement in a BNCT irradiation field. [ABSTRACT FROM AUTHOR]

When irradiated by high-power lasers, fused silica optical component can be ablated, which seriously affects their laser-conducing capability and service life. Numerical simulations have been applied to investigate the ablation process, laser-induced damage threshold (LIDT), and propagation loss of fused silica optical component. The depth of the ablation crater increases linearly with the duration of irradiation, while the rate of development in the width of the ablation crater gradually decreases. The LIDT of the front surface of the fused silica optical component will significantly decrease, while the propagation loss of the fused silica component will have a considerable increase when the front surface of fused silica is damaged under laser irradiation. The propagation loss and the LIDT of the fused silica’s front surface are 26.49, 21.19, 20.60, 16.83, and 16.41GW/cm2 and 0.41, 1.02, 2.24, 3.46, and 5.31dB, respectively, after 50, 100, 150, 200, and 250μs of ablation. This work provides novel opportunities for investigating the intrinsic mechanism of laser-induced damage to fused silica, and offers guidance for the future development of fused silica optical elements that are highly resistant to laser-induced damage. [ABSTRACT FROM AUTHOR]

Phase separation was observed in silica glass following low‐temperature heat treatment in high water vapor pressure through the formation of bubbles. Although the 6 day diffusion treatment in saturated water vapor pressure at 250°C does not normally cause phase separation, the reactive fracture surface and subsurface damage caused by polishing with cerium oxide (CeO2) allowed for an increase in water absorption during treatment and heterogeneous nucleation of the bubbles at damaged sites. The sub‐surface damage, characteristic of blunt contact damage, was only revealed when the polished sample was etched. The formation of bubbles and polishing damage were observed in two silica glasses—one containing chlorine impurities and the other containing OH impurities. Raman spectra collected after fracture or polishing and water diffusion treatment demonstrated an increase in the abundance of –OH species including silanol (SiOH) groups and an evolution in the glass structure in the bubble regions compared with the bubble‐free regions. These results indicate an increase in the reactivity between water and glass fracture surfaces relative to the bulk. [ABSTRACT FROM AUTHOR]

Rb2[TeS3] and Rb2[TeS3] ⋅ 1/3 H2O were obtained from rubidium azide (RbN3), tellurium and sulfur in 2 : 1 : 3 molar ratios from evacuated fused silica ampoules at 500 °C under more or less anhydrous conditions. Both compounds crystallize orthorhombically in the space group P212121 (Rb2[TeS3]: a=873.42(6) pm, b=1316.73(9) pm, c=2064.59(14) pm; Rb2[TeS3] ⋅ 1/3 H2O: a=872.97(6) pm, b=1299.82(9) pm, c=2148.26(15) pm, both at –173 °C for Z =12) and contain discrete ψ1‐tetrahedral [TeS3]2− anions (d(Te−S)=232–236 pm) in layerwise arrangements. The difference results from the water of hydration in Rb2[TeS3] ⋅ 1/3 H2O, which increases the coordination numbers of half of the six crystallographically distinct Rb+ cations from six and seven (only sulfur) to seven and almost eight by providing with oxygen from H2O an extra ligand (d(Rb−O)=290–318 pm). Red Rb2[TeS3] transforms pseudo‐topotactically into yellow Rb2[TeS3] ⋅ 1/3 H2O immediately upon contact with moist atmosphere. The compounds were screened with X‐ray diffraction, Raman and diffuse reflectance spectroscopy as well as thermal analysis. [ABSTRACT FROM AUTHOR]

Quartz glass powder is a type of silicon-rich industrial waste. Accumulation of this waste has led to resource wastage and environmental pollution. In this paper, quartz glass powder is used as raw material for preparing xonotlite through hydrothermal synthesis. The effects of Ca/Si (C/S) molar ratio, liquid/solid ratio, reaction temperature, and reaction time on the conversion of quartz are studied. The phase and structural changes of glass powder are analyzed by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Based on this, the conversion mechanism of quartz in glass powder is explained. The dissolution rate of quartz in an alkaline solution is a critical factor that restricts hydrothermal reactions. The conversion rate of quartz can be effectively increased by raising reaction temperature and extending reaction time. When the reaction temperature is 240 °C and the reaction time reaches 14 h, the conversion of quartz can reach 94.5 wt%. This study reveals the conversion mechanism of quartz in hydrothermal reactions and provides a theoretical basis for the efficient utilization of glass powder. [ABSTRACT FROM AUTHOR]

This study investigates the effects of boron nitride (BN) coating characteristics on the subsurface oxidation behavior of SiC/SiC composites in high‐temperature, water‐rich environments. Three types of coatings were examined: a crystalline stoichiometric BN, an amorphous BN, and a Si‐doped amorphous BN, the latter two containing 5–10 at% of oxygen and carbon. High‐resolution imaging and chemical analysis techniques were used to probe microstructural changes after oxidation at 1000°C for 1 or 12 h in flowing 20 vol% H2O, focusing on effects of coating thickness. Complementary chemical thermodynamic calculations and models for reaction‐ and transport‐controlled recession were used to interpret the experimental findings. Crystalline BN coatings produce open recession channels without forming borosilicate glass, a consequence of carbothermal reduction arising from C/CO produced through concomitant SiC oxidation. The combination of active oxidation and the relatively thick coatings in this system (ca. 1 µm) leads to a recession rate controlled by the intrinsic BN volatilization rate rather than the rate of gas transport. In contrast, amorphous coatings, both undoped and Si‐doped, readily oxidize to form borosilicate glasses that replace the BN. Broadly, the recession lengths increase with coating thickness. In the early stages, while the glass is boria‐rich and thus permeable to environmental oxidants, recession is controlled by the BN oxidation rate. As boria volatilizes, the silica concentration in the glass increases, eventually reaching the saturation limit and precipitating solid silica on the internal surfaces, essentially arresting further recession. [ABSTRACT FROM AUTHOR]

Hemispherical resonator gyroscope is a type of solid-state gyroscope, in which the fused silica hemispherical resonator with a high-quality factor (Q factor) is the key for the fabrication of high-performance devices. However, the metal film coated on the silica as the electrode for trigging the resonance often leads to the largely deteriorated Q factor. In this work, high-quality graphene films with controllable number of layers are uniformly coated on silica utilizing C2H4 as precursor in chemical vapor deposition. Replacing the metal film as the electrode, the hemispherical resonator coated with graphene demonstrates a Q factor of 3.38 × 106, with a high retention of 77.17%. At an optimized preparation temperature of 1130 °C, the graphene film shows a good adhesion with the silica hemisphere, providing an excellent candidate as the electrode for high-performance hemispherical resonators. [ABSTRACT FROM AUTHOR]

In disciplines like toxicology and pharmacology, oxygen (O2) respiration is a universal metric for evaluating the effects of chemicals across various model systems, including mammalian and microalgal cells. However, for these cells the common practice is to segregate populations into control and exposure groups, which assumes direct equivalence in their responses and does not take into account heterogeneity among individual cells. This lack of resolution impedes our ability to precisely investigate differences among experimental groups with small or limited sample sizes. To overcome this barrier, we introduce SlipO2Chip, an innovative glass microfluidic platform for precisely quantifying single-cell O2 respiration in the coordinated absence and presence of chemical solutes. SlipO2Chip comprises a wet-etched fused silica channel plate on the top and a dry-etched borosilicate microwell plate at the bottom. The microwells are coated with Pt(II) meso-tetra(pentafluorophenyl)porphine (PtTFPP), an O2 sensing optode material and an O2-independent reference dye. A custom 3D-printed holder facilitates the controlled horizontal movement ('slipping') of the channel plate over the microwell plate, thereby establishing or disrupting the fluid path over microwells. Collectively, these design elements enable the immobilization of single-cells in microwells, their exposure to controlled fluid flows, the coordinated opening and closing of microwells and repeated measurements of single-cell O2 respiration. Uniquely, by sequentially executing opening and closing it becomes possible to measure single-cell respiration prior to and after exposure to chemical solutes. In a proof-of-concept application, we utilized SlipO2Chip to measure the impact of increasing exposures of the marine bacterial signal 2-heptyl-4-quinolone (HHQ) on the dark respiration of the diatom Ditylum brightwellii at single-cell resolution. Results revealed a concentration-dependent decrease in per-cell O2 dark respiration, with a maximum reduction of 40.2% observed at HHQ concentrations exceeding 35.5 μM, and a half-maximal effective concentration (EC50) of 5.8 μM, consistent with that obtained via conventional bulk respiration methods. The ability of SlipO2Chip to sequentially assess the effects of chemical substances on single-cell O2 metabolism is advantageous for research where sample volumes are limited, such as clinical biopsies, studies involving rare microbial isolates, and toxicological studies aiming to address exposure effects while accounting for cell-to-cell variability. [ABSTRACT FROM AUTHOR]

Featured Application: Development of ultrapure materials technology. We demonstrate measurements of the absorption coefficient α ≈ 2.5 × 10−7 cm−1 in synthetic crystalline quartz at a wavelength of 1071 nm with a signal-to-noise ratio of 10/1 using the Time-resolved photothermal common-path interferometry (TPCI) scheme. It utilized cells filled with flowing argon and eliminated the influence of ambient air absorption. The scheme elements limiting the sensitivity of measurements at the level of ≈7.8 × 10−8 cm−1 were revealed. When these elements are replaced by better ones in terms of their thermal influence, the sensitivity of absorption coefficient measurements in crystalline quartz is ~10−8 cm−1. The calculation of the correction due to these optical elements of the values of the measured absorption coefficients is also described, which makes it possible to achieve the same sensitivity without replacing the elements. The improved scheme confirms the presence of the spatial inhomogeneity of absorption with a minimum coefficient of 2.5 × 10−7 cm−1 in synthetic crystalline quartz. The discrepancy of the absorption coefficient values in different regions of the crystal in the presented series of experiments was 2.5 × 10−7 cm−1 to 4 × 10−6 cm−1. Taking into account the ratio of thermo-optical parameters and the heat diffusion effect, the calculation shows that for quartz glasses the corresponding sensitivity of the absorption coefficient measurements equals ≈1.5 × 10−9 cm−1. [ABSTRACT FROM AUTHOR]

Thermochromic smart windows have been widely developed for solar regulation to save building energy. However, most current smart windows still exhibit a single responsiveness to a specific temperature, which is not conducive to daytime energy saving or nighttime privacy protection. Herein, a low‐temperature response is achieved by pre‐initiation of the monomer acrylamide (AAm) and acrylic acid (AA) in the synthesis of P(AAm‐co‐AA). Then, N‐isopropyl acrylamide and AAm are introduced into P(AAm‐co‐AA) to form a pre‐polymerized precursor solution. The liquid precursor solution can be encapsulated within two quartz glasses and synthesized in situ to prepare smart windows, which exhibit a high visible light transmittance of 84.4%, excellent solar modulation of 69.5%, and bidirectional temperature responsiveness (cold and hot). In addition, the upper critical solution temperature and the lower critical solution temperature of the hydrogel and the light transmission interval between the two temperatures can be flexibly adjusted to adapt to different climates and individual user needs. The designed smart window maintains a high light transmission within the human body's comfort temperature range. The bidirectional temperature response window achieves the dual functions of energy saving and privacy protection, making it an ideal smart window candidate with good prospects for practical applications. [ABSTRACT FROM AUTHOR]

The effects of density and shape of hollow silica (functionalized silica hollow tubes (FSHT) or hollow glass microspheres (FHGM)) on dielectric constant (εr) and dielectric loss (tan δ) of hindered phenol (HP) grafted functional polypropylene (FPP)/FSHT, heat-treated FPP (HTFPP)/FSHT, FPP/FHGM or HTFPP/FHGM substrate films were systematically investigated. The dielectric or free-volume-hole characteristics of FPP/FSHT, FPP/FHGM, HTFPP/FSHT, or HTFPP/FHGM films decrease to a minimum, as FSHT or FHGM contents approach an optimal value of 4wt% or 8wt%, respectively, and their dielectric or free-volume-hole characteristics decrease or increase gradually with increasing HP molar%. The minimum εr and tan δ of FPP/FSHT or HTFPP/FSHT films decrease significantly with decreasing FSHT's densities. By filling with 0.46 g/cm3 identical density of hollow silica fillers, the minimum εr or tan δ procured for FPP/FSHT or HTFPP/FSHT films are somewhat smaller than those of corresponding FPP/FHGM or HTFPP/FHGM films. The linear coefficient of thermal expansion (LCTE) or onset degradation temperature (DTonset) of FPP/FSHT, HTFPP/FSHT, FPP/FHGM or HTFPP/FHGM films reduce or increase visibly with increasing FSHT or FHGM contents, respectively. All DTonset values of HTFPP/hollow silica films are ~ 150℃ higher than those of conventional PP polymers. Satisfactorily low εr/tan δ (1.74/0.0019, 1.83/0.0020, 1.83/0.0024 and 1.92/0.0028 at 1 MHz), LCTE (95 × 10–6/℃, 89 × 10–6/℃, 80 × 10–6/℃ and 74 × 10–6/℃) and pleasing heat-resisting properties for 6G ultrarapid communication are acquired for properly prepared FPP/FSHT, HTFPP/FSHT FPP/FHGM or HTFPP/FHGM substrate films having 1.2 HP molar% and 0.46 g/cm3 density of FSHT and FHGM fillers. Probable reasons accounting for these reduced dielectric, LCTE and improved heat-resisting characteristics are proposed. [ABSTRACT FROM AUTHOR]

The evolution of microstructures can be observed in various engineering and natural materials, such as special alloys, silica glasses or soils. These macroscopic and microscopic effects are often controlled by thermal and chemical changes or extern forces. In addition, several phases are usually involved in these processes, whose energy potentials result in a non‐convex total energy. A theory is introduced that can be applied to a wide range of elasto‐plastic materials with kinematic hardening. In order to obtain a general model, a relaxed free energy in small strain theory is defined using variational principles for inelastic materials. This energy includes the dissipation of the substance as so‐called dissipation distance to facilitate a time‐stepped incremental representation. Furthermore, the phase volume fractions are contained in the weighted sum of the individual energies and are expressed here using Young measures. In the centre of the model, transition rates with underlying ordinary differential equations (ODEs) are calculated, which allow access to the phase evolution of the system. The initial results and the behaviour of this theory are explained using numerical simulations created with the programming language Julia. [ABSTRACT FROM AUTHOR]

The acoustoelectric (AE) effect induced by the absorption of ultraviolet (UV) light at 365 nm in piezoelectric ZnO films was theoretically and experimentally studied. c-ZnO films 4.0 µm thick were grown by the RF reactive magnetron sputtering technique onto fused silica substrates at 200 °C. A surface acoustic wave (SAW) delay line was fabricated with two split-finger Al interdigital transducers (IDTs) photolithographically implemented onto the ZnO-free surface to excite and reveal the propagation of the fundamental Rayleigh wave and its third harmonic at about 39 and 104 MHz. A small area of a few square millimeters on the surface of the ZnO layer, in between the two IDTs, was illuminated by UV light at different light power values (from about 10 mW up to 1.2 W) through the back surface of the SiO2 substrate, which is optically transparent. The UV absorption caused a change of the ZnO electrical conductivity, which in turn affected the velocity and insertion loss (IL) of the two waves. It was experimentally observed that the phase velocity of the fundamental and third harmonic waves decreased with an increase in the UV power, while the IL vs. UV power behavior differed at large UV power values: the Rayleigh wave underwent a single peak in attenuation, while its third harmonic underwent a further peak. A two-dimensional finite element study was performed to simulate the waves IL and phase velocity vs. the ZnO electrical conductivity, under the assumption that the ZnO layer conductivity undergoes an in-depth inhomogeneous change according to an exponential decay law, with a penetration depth of 325 nm. The theoretical results predicted single- and double-peak IL behavior for the fundamental and harmonic wave due to volume conductivity changes, as opposed to the AE effect induced by surface conductivity changes for which a single-peak IL behavior is expected. The phenomena predicted by the theoretical models were confirmed by the experimental results. [ABSTRACT FROM AUTHOR]

We measured the temporal voltage response of NbTi superconducting filaments with varied nanoscale thicknesses to step current pulses that induce non-equilibrium superconducting states governed by a hot spot mechanism. Such detected voltage emerges after a delay time  t d , which is intimately connected to the gap relaxation and heat escape times. By employing time-dependent Ginzburg–Landau theory to link the delay time to the applied current, we determined that the gap relaxation time depends linearly on film thickness, aligning with the acoustic mismatch theory for phonon transmission at the superconductor–substrate interface. We thereby find a gap relaxation time of 104 ps per nm of thickness for NbTi films on polished sapphire. We further show that interfacial interaction with the substrate significantly impacts the gap relaxation time, with observed values of 9 ns on Si O x , 6.8 ns on fused silica, and 5.2 ns on sapphire for a 50 nm thick NbTi strip at  T = 5.75  K. These insights are valuable for optimizing superconducting sensing technologies, particularly the single-photon detectors that operate in the transient regime of nanothin superconducting bridges and filaments. [ABSTRACT FROM AUTHOR]

Sodium hydroxide (NaOH) is increasingly drawing attention as a highly selective etchant for femtosecond laser-modified fused silica. Unprecedented etching contrasts between the irradiated and pristine areas have enabled the fabrication of hollow, high-aspect-ratio structures in the bulk of the material, overcoming the micrometer threshold as the minimum feature size. In this work, we systematically study the effect of NaOH solutions under different etching conditions (etchant concentration, temperature, and etching time) on the tracks created by tightly focused femtosecond laser pulses to assess the best practices for the fabrication of hollow nanostructures in bulk fused silica. [ABSTRACT FROM AUTHOR]

Traditional interpolation algorithms often fail to meet the precision requirements of ultra-precision machining when applied to super-precision polishing machines. Moreover, the processing of fused silica glass optical components is frequently threatened by mechanical impacts due to their fragility. In order to address this issue, this paper proposes a high-precision motion interpolation method based on fourth-order Runge-Kutta and velocity-flexible planning. This method is designed for open-architecture small multi-axis optical polishing machines to polish quartz glass. The algorithm initially employs composite Simpson's rule to calculate the lengths of sub-paths within the polishing trajectory. Based on these length values, flexible velocity planning is executed to ensure the smooth continuity of velocity, acceleration, and jerk during motion interpolation. This reduces the risk of mechanical impacts that could damage the components during the machining process. The introduction of the adaptive fourth-order Runge-Kutta method significantly enhances the parameter point calculation accuracy of NURBS curves. The incorporation of adaptive principles also maintains a higher processing speed, thereby greatly improving processing efficiency. This method comprehensively addresses both the precision of curve interpolation and execution efficiency. Finally, experimental validation is conducted on an open-architecture small multi-axis optical polishing machine. The proposed method based on FRKVF not only mitigates mechanical impacts resulting from discontinuous acceleration, thereby ensuring the machining quality of optical components, but also satisfies the high-precision requirements for processing fused silica optical elements. • Trigonometric functions enhance curve controllability, reducing the risk of mechanical damage during optical processing. • Adaptive 4th-order Runge-Kutta method improves NURBS curve calculation accuracy and efficiency for ultra-precision machining. • Five-axis small tool polishing machine experiment shows a significant reduction in surface roughness and height difference. • Surface roughness decreased by 34.8% and 24.2%; RMS value by 35% and 23%; peak-valley by 15.5% and 26.8%, respectively. [ABSTRACT FROM AUTHOR]

For conventional optical manufacturing combining ion beam figuring (IBF) and abrasive finishing, it is difficult to achieve an atomic-scale smooth surface with microroughness below 0.1 nm. Because the abrasives inevitably damage the surface, and the damages are exposed during ion sputtering. To solve this problem, plasma-induced atom migration manufacturing (PAMM) and IBF were combined in this study. PAMM is a damage recovery process based on atom migration effect. In this study, PAMM was employed to recover the subsurface damage and then the damage-less surface was further processed by IBF to remove the form error as well as reduce the roughness to atomic level. Full spatial frequency error convergence was achieved via the combined process of PAMM and IBF. A good surface accuracy of 3.89 nm RMS and an atomically smooth surface with a roughness of 0.044 nm were obtained. The less damage characteristic of the hybrid process was also demonstrated by buffered oxide etching (BOE). This study proposed and verified a hybrid process combining PAMM for damage recovery and IBF for figuring and atomic-scale smoothing, which provided a novel process strategy for manufacturing ultra-precision optics with high quality. • Plasma-induced atom migration (PAMM) and ion beam figuring (IBF) were combined for fused silica. • Subsurface damage evolved into micro pits during IBF, which hindered further roughness reduction. • PAMM recovered the subsurface damage, then IBF removed the form error as well as reduced the roughness to atomic level. • PAMM-IBF process realized full spatial frequency convergence, with RMS 3.89 nm and Sa 0.044 nm in LSF and HSF error. [ABSTRACT FROM AUTHOR]

This paper presents the results of a detailed theoretical study of the bending properties of original all-glass leakage channel microstructured optical fibers (LC MOFs) over a bending radius range from 3 cm to 11 cm. These LC MOFs contain two layers of fluorine-doped silica glass elements with reduced refractive index, different diameters, and different distances between them. We determined the spatial distributions of the electric field components of different modes in addition to the usual parameters such as effective refractive indices, bending losses, and spatial intensity distributions. A detailed analysis showed that three modes for each polarization have to be considered to correctly calculate the bending losses. Two pairs of these three modes couple in two distinct bending radius ranges, specifically near 3.68 cm and near 5.95 cm, and the mode coupling in these pairs is resonant. The resulting bending losses of the LC MOF for two polarizations are very close to each other and have two maxima at bending radii of 3.68 cm and 5.95 cm. However, the nature of these maxima is not resonant; they are caused by the combined influence of all three modes, each of which has specific dependencies of losses and other parameters on the bending radius that exhibit quasi-resonant behavior near the corresponding bending radii. [ABSTRACT FROM AUTHOR]

In this paper, a quartz glass with low hydroxyl groups was prepared by combining the advantages of various processes, using a plasma heat source as the flame and high-purity quartz sand as the raw material. The purity of the quartz sand was 99.997%. The number of air bubbles in the quartz glass prepared using high-purity quartz sand was lower. The hardness and tensile strength of the quartz glass were 737.7–767.1 GPa and 6.88–9.64 MPa, respectively. The hydroxyl content of the sample was only 4.11 ppm, and the hydroxyl content of the homogenized quartz glass was reduced to 2.64 ppm, which was an improvement of about 35%. After homogenization, the fictive temperature (Tf) of the quartz glass was determined to be 1253 cm−1, and the variation of the Tf value along the radial direction was reduced, indicating a more homogeneous glass structure. The stress distribution in the quartz glass was significantly improved. These results indicate that the preparation of quartz glass from high-purity quartz sand using a plasma heat source as the flame opens up new avenues for optical applications. [ABSTRACT FROM AUTHOR]

Photocatalytic coatings have the potential to contribute to the purification of water via an advanced oxidation process (AOP). A commonly used method for analyzing the mechanism of the photocatalytic performance of a given reactor type is to document the degradation behavior in a solution containing methylene blue. However, since methylene blue is rather unstable, the degradation results should be viewed critically. In this work, the degradation behavior of a test solution with methylene blue on quartz glass surfaces coated with photocatalytic titanium dioxide (TiO2) of the anatase modification was investigated through a variety of different light sources. The coating was deposited by physical vapor deposition (PVD) with the reactive pulsed DC magnetron sputtering ion plating (MSIP) method described in the study by Desch and Lake, while the quartz glasses were coated with a 100 nm thick TiO2 coating on the outside. The same glasses were used for all experiments with TiO2. In the determination of the degradation rate, additional experiments were performed using pure quartz glass without any coating, which made it possible to examine the influence of different light sources on the degradation rate of methylene blue in general. Three different light sources, namely UV‐A, UV‐C, and simple fluorescent lamps were used in this study. The concentration of methylene blue was recorded by photo spectrometer in 10‐min increments throughout the experiment and the experiments were performed for 24 h in all cases. Our data indicates that the methylene blue test is a poor method because the degradation rate is not clearly differentiable due to the low stability of the test substance. Without including reference testing in the absence of a catalyst, data may be subject to misinterpretation. [ABSTRACT FROM AUTHOR]

In this study, titanium metal (99.99%) was deposited on quartz glass substrate test specimens by DC magnetron sputtering. Thereafter, radio-frequency magnetron sputtering was used to create an oxide layer of ITO:Ga (97.3 at%) to form a final dual-layer transparent and conductive film on the glass substrate. The film was then annealed at different temperatures under vacuum. The thermal energy rearranged the internal crystalline structure, and this reduced the number of crystalline defects. The multilayer structure of the dual-layer film was explored after annealing: the film thickness, electrical properties, transmission properties, surface structure, grain size, and quality factors were all analyzed. The results showed that the electrical properties of ITO:Ga/Ti improved after annealing at 500 °C (100 W; 30 min) and that the resistivity was 6.51 × 10-4 O·cm. The average penetration of ITO:Ga/Ti after annealing at 400 °C was 87.52%, and after annealing at 500 °C, it was 89.70%. The figure of merit was the optimal value of 4.78 × 10-3 O-1 after annealing at 500 °C. [ABSTRACT FROM AUTHOR]

The emission of high-order harmonics from solids under intense laser-pulse irradiation is revolutionizing our understanding of strong-field solid-light interactions, while simultaneously opening avenues towards novel, all-solid, coherent, short-wavelength table-top sources with tailored emission profiles and nanoscale light-field control. To date, broadband spectra in solids have been generated well into the extreme-ultraviolet (XUV), but the comparatively low conversion efficiency in the XUV range achieved under optimal conditions still lags behind gas-based high-harmonic generation (HHG) sources. Here, we demonstrate that two-color high-order harmonic wave mixing in a fused silica solid is more efficient than solid HHG driven by a single color. This finding has significant implications for compact XUV sources where gas-based HHG is not feasible, as solid XUV wave mixing surpasses solid-HHG in performance. Moreover, our results enable utilizing solid high-order harmonic wave mixing as a probe of structure or material dynamics of the generating solid, which will enable reducing measurement times compared to the less efficient regular solid HHG. The emission intensity scaling that follows perturbative optical wave mixing, combined with the angular separation of the emitted frequencies, makes our approach a decisive step for all-solid coherent XUV sources and for studying light-engineered materials. High-order harmonic generation in solids could develop into a compact, coherent, short-wavelength source. This study shows that two-colour noncollinear wave mixing in silica significantly enhances HHG efficiency over single-color methods, offering a novel pathway for advancing all-solid XUV sources. [ABSTRACT FROM AUTHOR]

Thee‐dimensional nano‐structuring of bulk fused silica glass remains a challenging issue due to limitations of traditional fabrication methods. In the present work the fabrication of hollow mm‐length channels is demonstrated in bulk fused silica by femtosecond laser irradiation followed by chemical etching, achieving feature sizes of 300 nm. The tight focusing and threshold energy conditions allow to reveal unexplored fabrication regimes. The robustness and repeatability of the process are demonstrated through the fabrication of fused silica diffraction gratings, made of parallel hollow channels with variable pitches even in the sub‐wavelength regime. [ABSTRACT FROM AUTHOR]

The growing importance of submicrometer‐structured surfaces across a variety of different fields has driven progress in light manipulation, color diversity, water‐repellency, and functional enhancements. To enable mass production, processes like hot‐embossing (HE), roll‐to‐roll replication (R2R), and injection molding (IM) are essential due to their precision and material flexibility. However, these processes are tool‐based manufacturing (TBM) techniques requiring metal molds, which are time‐consuming and expensive to manufacture, as they mostly rely on galvanoforming using templates made via precision microlithography or two‐photon‐polymerization (2PP). In this work, a novel approach is demonstrated to replicate amorphous metals from fused silica glass, derived from additive manufacturing and structured using hot embossing and casting, enabling the fabrication of metal insets with features in the range of 300 nm and a surface roughness of below 10 nm. By partially crystallizing the amorphous metal, during the replication process, the insets gain a high hardness of up to 800 HV. The metal molds are successfully used in polymer injection molding using different polymers including polystyrene (PS) and polyethylene (PE) as well as glass nanocomposites. This work is of significant importance to the field as it provides a production method for the increasing demand for sub‐micron‐structured tooling in the area of polymer replication while substantially reducing their cost of production. [ABSTRACT FROM AUTHOR]

This study investigates the radiation shielding properties of glass samples within the xGd2O3‐5SiO2‐40Na2O‐(54.5‐x) B2O3:0.5CeF3 composition, where x varies from 0 to 10 mol.%, which is coded as GSNBCX (X = 1, 2, 3, and 4). The assessment is done through comprehensive Monte Carlo simulation and Phy‐X/PSD software analyses. The primary objective of this study is to comprehensively evaluate the radiation shielding properties of glass compositions with varying Gd2O3 concentrations. This evaluation encompasses both the attenuation of gamma radiation within the broad energy range of 0.015 MeV to 15 MeV and the assessment of fast neutron removal cross sections, with a specific focus on simulations spanning energy levels from 0.5 to 10 MeV. By examining these parameters, we aim to elucidate the impact of Gd2O3 concentration on the material's overall effectiveness in radiation shielding applications. The results reveal a significant variation in the mass attenuation coefficient (μm) across the investigated glass samples. For instance, μm values range from 3.244 to 0.019 cm2·g−1 for GSNBC1, 20.471 to 0.025 cm2·g−1 for GSNBC2, 27.245 to 0.027 cm2·g−1 for GSNBC3, and 32.223 to 0.029 cm2·g−1 for GSNBC4. Notably, GSNBC4, characterized by a substantial Gd2O3 concentration (10 mol.%), exhibits the highest values of both μm and linear attenuation coefficient (μ). Furthermore, the investigation delves into the fast neutron removal cross section (FNRCS), which displays values of 0.97, 0.95, 0.094, and 0.93 cm−1, respectively. GSNBC1, marked by its elevated B2O3 content (54.5 mol.%), showcases the highest FNRCS. These findings underscore the efficacy of Gd2O3‐doped materials in shielding against gamma rays, holding promise for various applications in radiation protection, particularly in the medical and nuclear sectors. This study contributes valuable insights into developing effective radiation‐blocking materials for diverse industrial and scientific contexts. [ABSTRACT FROM AUTHOR]

The preparation of fused silica glass with microstructural patterns has attracted considerable interest, and the process chain of using nano-silica powders mixed with organic polymers to prepare composites for molding, degreasing, and sintering provides a good solution. However, the potential negative effects of organic residues cannot be avoided. In this study, a pattern stencil replication method with silica gel using high-purity quartz fibers as reinforcement is proposed for preparing micropatterned fused silica glass. The microscopic morphology and mechanical properties before and after silica gel drying and the optical properties of fused silica glass obtained by sintering were evaluated via transmission electron microscopy), three-point bending strength test, scanning electron microscopy, X-ray diffraction spectrum analysis, ultraviolet–visible and infrared measurements. The results showed that quartz fiber as a reinforcer could shorten the drying time of the gel and did not degrade the quality of the fused silica glass obtained by sintering. Laser confocal test results showed that microlens arrays were generated by template replication, demonstrating the feasibility of molding fused silica lens arrays with small feature sizes and providing new ideas for the preparation of bulk fused silica glass or micropatterned glass. [ABSTRACT FROM AUTHOR]

Mechanical properties of glass are critical for technical applications, thus comprehending the material response to mechanical tests is of great importance. In this study, we employ the nanoindentation combined with nanoscale infrared (nano-IR) spectroscopy combined with scattering-type scanning near-field optical microscopy (s-SNOM) and ToF-SIMS, to elucidate the nanoindentation rate dependence of plastic deformation of soda lime silicate glass. Experiment results show that the nanohardness and elastic modulus of soda lime silicate (SLS) glass exhibit a strong dependence on loading rate, while those of fused quartz (FQ) shows a much weaker dependence. The residual indent volume at fast loading conditions is smaller for SLS glass than FQ; but as the loading rate decreases, the residual indent volume of FQ and SLS glass becomes similar. The indent volume of SLS glass after sub- T g annealing (reverting subsurface densification) shows negligible dependence on the loading rate, suggesting that the densification of SLS glass is strongly enhanced at lower indentation rate, but the shear flow is independent or weakly dependent. Using nanoscale infrared spectroscopy and ToF-SIMS techniques, the sodium ion migration in SLS glass surface in the indent is found to be associated with the subsurface densification. These results suggest the possible role of highly mobile sodium ions on in nano- and micro-scale plastic deformation behavior of SLS glass. [ABSTRACT FROM AUTHOR]

As the flight speed of aircraft continues to increase, high-temperature wave-transparent materials for radomes or antenna windows face great challenges. The shortage of new high-performance wave-transparent materials is limiting the improvement of aircraft performance. In this work, dielectric and mechanical properties of RE 2 SiO 5 (RE = Ho, Er, Tm, Yb, and Lu) were investigated to explore their application as high-temperature wave-transparent materials. RE 2 SiO 5 (RE = Ho, Er, Tm, Yb, and Lu) ceramics possess relatively low dielectric constant and it is insensitive to the RE species. For the dielectric loss, they gradually decrease as the radius of rare earth ions decreases. In addition, RE 2 SiO 5 (RE = Ho, Er, Tm, Yb, and Lu) possesses good mechanical properties with high hardness and relatively low reduced modulus, and hardness is insensitive to the rare earth ion radii while the reduced modulus increases with the RE3+ ions radius decreases. They are larger than those of fused silica, the most used traditional high-temperature wave-transparent material. The results provide important material selection and optimization guidelines for RE 2 SiO 5 as the candidate for next-generation high-temperature wave-transparent materials. [ABSTRACT FROM AUTHOR]

The anti-reflection (AR) technology currently used in photovoltaic (PV) glass has reached its operational limit as the refractive index of existing materials cannot be lowered further. To overcome this, in this study, we selected formed methylsiloxane as an AR layer for PV glass. Its low refractive index (∼1.37) originates from the high content of methyl groups and the formation of voids during crosslinking. We acquired and compared the refractive index curves, conducted structural analyses, characterizations (optical, thermal, and surface), and performance evaluations to confirm the advantages of silicone as an AR layer for PV panels. The spreading and subsequent room-temperature self-curing characteristics of silicone considerably enhanced its applicability for upscaling and repair. The hydrophobic nature of the silicone AR layer imparted a new self-cleaning function to the solar panels; further, the methyl-silicone coating enhanced light transmission, resulting in electrical gain. Furthermore, the addition of the methyl-silicone layer created a refractive index gradient on the glass surface, making it fully compatible for use with the mainstream AR process, namely, the sol-gel method employed for PV glass. [ABSTRACT FROM AUTHOR]

Nanocones are ideal for wide‐angle antireflection of glass elements, yet their applications often encounter complex geometries and large sizes, bringing serious difficulty in developing a reliable and efficient manufacturing process. Here, an in situ dewetting assisted plasma etching (In situ DAPE) method is proposed to engrave nanocones on arbitrarily structured glass elements in one step. While exposed to high‐energy plasma, pre‐sputtered platinum (Pt) film undergoes dewetting, forming uniformly distributed nanoparticles that act as in situ sacrificial masks for plasma etching to generate nanocones. The nanocone size is decided by nanoparticle size, which can be modified through the Marangoni effect of the melted Pt film. Incorporating a passivation step can improve the aspect ratio of nanocones up to ≈8:1 due to the trench effect. Nanocones with diameters ranging from 62 to 136 nm and heights from 126 to 942 nm can be achieved. The nanocones help to achieve an average transmittance of 98% over the 0.3–2.5 µm spectrum and a 79.4% laser‐induced damage threshold of bare fused silica. The efficient fabrication of nanocones over multiple glass elements is demonstrated including a 2‐inch flat window, cylindrical microlens array, and diffractive grating, highlighting the efficacy of the In situ DAPE method for high‐performance optical elements. [ABSTRACT FROM AUTHOR]