Search Results (99)

This review examines the design of thermal control systems for state-of-the-art deep ultraviolet (DUV) and extreme ultraviolet (EUV) projection lithography tools. The lithographic system under investigation integrates several critical subsystems along the optical transmission chain, including the light source, reticle stage, projection optics (featuring DUV refractive lenses and EUV multilayer mirrors), immersion liquid, wafer stage, and metrology systems. Under high-power irradiation conditions with concurrent thermal perturbations, the degradation of thermal stability and gradient uniformity within these subsystems significantly compromises exposure precision. Through a systematic analysis of the thermal challenges specific to each subsystem, this review synthesizes established thermal control systems across two technical dimensions: thermal control structures and thermal control algorithms. Prospects for future advancements in lithographic thermal control are also discussed. Full article

Retired chemically polluted sites in southern Jiangsu Province, China, are characterized by dense nonaqueous phase liquids (DNAPLs) and extremely thick aquifers (>30 m), which pose substantial challenges for determining investigation and remediation depths during redevelopment and exploitation. This study constructed a 2D groundwater transport model using TMVOC to systematically investigate the migration, diffusion, and natural attenuation processes of two typical DNAPLs—1,2-dichloroethane (DCE) and carbon tetrachloride (CTC)—under three scenarios: individual transport, mixed transport, and heterogeneous aquifer conditions, with a simulation period of 35 years. In individual transport scenarios, DCE and CTC showed distinct migration behaviors. DCE achieved a maximum vertical transport distance of 14.01 m and a downstream migration distance of 459.58 m, while CTC reached 13.57 m vertically and 453.51 m downstream. When transported as a mixture, their migration was inhibited: DCE’s vertical and downstream distances decreased to 13.76 m and 440.46 m, respectively; and CTC’s to 13.23 m and 420.32 m, likely due to mutual solvent effects that altered their physicochemical properties such as viscosity and solubility. Under natural attenuation conditions, both DNAPLs ceased downstream transport by the end of the 6th year. DCE concentrations dropped below its risk control value (0.81 mg/L) by the 14th year, and CTC (with a risk control value of 0.23 mg/L) by the 11th year. By the 10th year, DCE’s downstream plume had retreated to 48.65 m, and CTC’s to 0.95 m. In heterogeneous aquifers, vertical upward transport of DCE and CTC increased to 14.82 m and 14.22 m, respectively, due to the partial absence of low-conductivity silt layers, while their downstream distances decreased to 397.99 m and 354.11 m, constrained by low-permeability lenses in the migration path. These quantitative results clarify the dynamic differences in DNAPL transport under varying conditions, highlighting the impacts of multicomponent interactions, natural attenuation, and aquifer heterogeneity. They provide critical references for risk management, scientific determination of remediation depths, and safe exploitation of retired chemically polluted sites with similar hydrogeological characteristics. Full article

A double-sided telecentric zoom optical system can ensure the measurement and detection accuracy for different workpiece sizes and plays a crucial role in industrial detection. The conventional double-sided telecentric mechanical zoom system is faced with the problem of complex structure and difficult focusing. To address these issues, a liquid lens is applied to design a non-displacement double-sided telecentric zoom system in this paper. Here, the design method of the conventional double telecentric zoom system is analyzed first; then, the liquid lenses are substituted for the mechanical motion groups. Finally, a double-sided telecentric zoom system with a detection range of 25~60 mm and a magnification of −0.44×~−0.183× has been designed and optimized by Zemax software. The design results show that in the process of magnification, the root mean square radius of the diffuse spot in the system is smaller than the pixel size during the process of zooming. The modulation transfer function values at the Nyquist frequency of 80 lp/mm are all above 0.4, distortion is controlled within 0.2, and telecentricity is less than 0.5°, indicating that the system has excellent imaging quality, low distortion, and high telecentric and other characteristics, which meet system requirements. The design method proposed in this paper can provide an effective solution for the rapid conversion of displacement zoom systems to non-displacement zoom systems. Full article

As the core element of adaptive optical systems, tuneable lenses are essential in adaptive optics. Dielectric elastomer-driven tuneable lenses offer significant advantages in tuning range, response speed, and lightweight design compared to traditional mechanical zoom lenses. This paper systematically reviews the working mechanisms and research advancements of these lenses. Firstly, based on the two driving modes of deformation zoom and displacement zoom, the tuning principle of dielectric elastomer-driven tuneable lenses is analysed in depth. Secondly, the design methodology and current status of the research are systematically elaborated for four typical structures: monolithic, composite, array, and metalenses. Finally, the potential applications of this technology are discussed in the fields of auto-zoom imaging, microscopic imaging, augmented reality display, and infrared imaging, along with an analysis of the key technological challenges faced by this technology, such as material properties, modelling and control, preparation processes, and optical performance. This paper aims to provide a systematic reference for researchers in this field and to help promote the engineering application of dielectric elastomer tuneable lens technology. Full article

Structural color is a kind of natural color that widely exists in nature. The ordered microstructure of nano materials can absorb or reflect light of specific wavelength, thus showing colorful colors. Structural color is an ideal choice for color contact lens pattern pigment due to its good tinting degree, stability, and nontoxicity. This paper explores a method for synthesis of zinc oxide (ZnO) nanoparticles with a high refractive index and enhancement of the brightness of the structured colors by introducing carbon black nanoparticles. This method is convenient and successful to prepare ZnO ink, which can produce bright structural colors, and to produce color patterns through rubber pad printing. It is worth mentioning that ZnO nanoparticles can be self-assembled and arranged in contact lens ink without subsequent complicated processing. At the same time, the color only comes from ZnO and carbon black. While there is no other organic matter, the presence of nanoparticles plays a certain role in sterilization. Blue contact lenses prepared by this method have bright structural color, high oxygen permeability, and high hydrophilicity. At the same time, a cell viability test showed that the contact lenses prepared by this method had low adsorption capacity for lipids and proteins, reflecting the photonic crystal’s high biocompatibility. In summary, a trend for future research is to use high-refractive-index zinc oxide nanoparticles to produce structural colors rather than employing conventional contact lens pigments. Full article

Modern applications of molecular liquid crystals span from high-resolution displays for augmented and virtual reality to miniature tunable lasers, reconfigurable microwave devices for space exploration and communication, and tunable electro-optical elements, including spatial light modulators, waveguides, lenses, light shutters, filters, and waveplates, to name a few. The tunability of these devices is achieved through electric-field-induced reorientation of liquid crystals. Because the reorientation of the liquid crystals can be altered by ions normally present in mesogenic materials in minute quantities, resulting in their electrical resistivity having finite values, the development of new ways to control the concentration of the ions in liquid crystals is very important. A promising way to enhance the electrical resistivity of molecular liquid crystals is the addition of nano-dopants to low-resistivity liquid crystals. When nanoparticles capture certain ions, they immobilize them and increase their resistivity. If properly implemented, this method can convert low-resistivity liquid crystals into high-resistivity liquid crystals. However, uncontrolled ionic contamination of the nanoparticles can significantly alter this process. In this paper, building on our previous work, we explore how physical parameters such as the size of the nanoparticles, their concentration, and their level of ionic contamination can affect the process of both enhancing and lowering the resistivity of the molecular liquid crystals. Additionally, we analyze the use of two types of nano-dopants to achieve better control over the electrical resistivity of molecular liquid crystals. Full article

Standard endoscopy of vocal folds is in general limited to two-dimensional imaging. Laser-based 3D imaging offers not only absolute measurements but also the possibility of assessing all three spatial directions. However, due to human inter-individuality, a fixed grid configuration (with fixed edge length and spot size) does not necessarily provide the best coverage and resolution. We present a liquid lens optical design for a diffractive spot array generator with dynamic adjustment capabilities for both array size and spot size. The tunable nature of the liquid lenses enables precise control over the spot array generated by a diffractive optical element (DOE). The first liquid lens controls the spot divergence in the observation plane, while the second liquid lens adjusts the zoom factor. The optical configuration provides a dynamic range of 1.8 with respect to array size, significantly enhancing adaptability in imaging across various applications. Full article

Optical imaging systems using varifocal lenses have been widely used in many applications over the past several decades, such as machine vision devices, consumer electronic products, and medical instruments. Traditional varifocal lenses often consist of multiple solid focal length refractive optical elements. The varifocal ability is obtained by dislocating these optical elements along the optical axis over specific distances using mechanical driving mechanisms. It makes the traditional optical varifocal imaging systems suffer from bulky dimensions, slow response speed, complicated configuration, and discrete magnifications. Adaptive varifocal lenses have been a better choice to address the aforementioned limitations of traditional varifocal lenses. Dielectric elastomer actuators (DEA), which can effectively respond to an electric field and result in shape deformation, have been used to develop various adaptive lenses. This paper aims to give a brief review of adaptive varifocal lenses based on DEA. First, this paper describes the basic physical mechanism of DEA. Second, this paper reviews adaptive varifocal liquid lenses based on DEA and introduces their material, structure, and fabrication process, focusing on their unique advantages, such as fast response speed and compactness. However, despite these merits, the adaptive varifocal liquid lens still has challenges in environment stability and liquid leakage. To address these challenges, adaptive varifocal soft solid lenses based on DEA have been proposed, which are also reviewed. In addition, other adaptive varifocal lenses, including metalens, Fresnel lens, microlens array, and Alvarez lens, are also presented. Finally, the prospects and challenges for the development of adaptive varifocal lenses based on DEA are discussed. Full article

The residual non-aqueous phase liquid (NAPL) within low-permeability lenses of aquifers is a major contributor to “tailing”, a phenomenon that complicates the remediation of NAPL-contaminated sites. A fundamental challenge in addressing this issue is the lack of understanding of the primary controlling factors and underlying effects of NAPL residuals in these aquifer lenses. This study aims to identify the key factors and mechanisms affecting NAPL residuals in low-permeability lenses through a series of experimental approaches. These include soil column simulation experiments on NAPL residuals in various low-permeability lenses, adsorption experiments on aquifer and lens particles, pore mercury intrusion testing, and particle size distribution analysis. The experiments provided valuable data on residual NAPL saturation S_R, particle adsorption capacity, particle size, gradation, and pore size and distribution in different lenses. Using a mass conservation approach, the particle adsorption contributed less than 0.5% to the total NAPL residuals, while retention accounted for more than 99.5%, highlighting that retention is the dominant mechanism governing NAPL persistence in these lenses. The mechanism underlying this result was further clarified through an analysis of particle size characteristics. Correlation analysis was conducted to examine the relationships between residual NAPL and macropore porosity (n_max, diameter > 60 μm), mesopore porosity (n_mid, diameter = 30~60 μm), and small pore porosity (n_min, diameter < 30 μm). The results demonstrated that mesopores exhibited the strongest correlation with NAPL retention, due to their pronounced capillary action and sufficient storage capacity for NAPL. Full article

Background and Objectives: In previous studies, we reported that the assessment of the cumulative thermal dose in the crystalline lens, conducted through computational modeling utilizing a supercomputer and the biothermal transport equation, exhibited a significant association with the incidence of nuclear cataracts. In this study, we have investigated the types of proteins that expressed underlying 35.0 °C (normal-temp) and 37.5 °C (warming-temp) by using the shotgun liquid chromatography (LC) with tandem mass spectrometry (MS/MS)-based global proteomic approach. Materials and Methods: We have discussed the changes in protein expression in warmed iHLEC-NY2 cells using Gene Ontology analysis and a label-free semiquantitative method based on spectral counting. Results: In iHLEC-NY2, 615 proteins were detected, including 307 (49.9%) present in both lenses cultured at normal-temp and warming-temp, 130 (21.1%) unique to the lens cultured at normal-temp, and 178 (29.0%) unique to the lens cultured at warming-temp. Furthermore, LC–MS/MS analysis showed that warming decreased the expression of actin, alpha cardiac muscle 1, actin-related protein 2, putative tubulin-like protein alpha-4B, ubiquitin carboxyl-terminal hydrolase 17-like protein 1, ubiquitin-ribosomal protein eL40 fusion protein, ribosome biogenesis protein BMS1 homolog, histone H2B type 1-M, and histone H2A.J. in iHLEC-NY2. Conclusions: The decreases in the specific protein levels of actin, tubulin, ubiquitin, ribosomes, and histones may be related to cataract development under warming conditions. This investigation could provide a critical framework for understanding the correlation between temperature dynamics and the development of nuclear cataracts. Full article

The pancake structure is the mainstream optical solution for virtual reality (VR) displays due to its compact, folded optical path. However, only a small portion of the light can pass through the pancake optical engine because the incident light has to be polarized and directed to the half mirror (HM) twice. In order to improve the optical efficiency, a new pancake optical engine is proposed for VR display, which employs a diffractive deflection film (DDF) with different focal lengths in three regions and two cholesteric liquid crystal (CLC) lenses that respond to circularly polarized light. The CLC lenses are modeled, and their polarization response characteristics are verified. The pancake system is simulated and optimized in terms of image quality and evaluated for optical efficiency, achieving 2.86 times the optical efficiency of the conventional pancake system, and the root mean square (RMS) radius of the system is controlled within 19 μm, and the modulation transfer function (MTF) at the cut-off frequency is greater than 0.2. The results indicate that this structure has great potential in the VR display field. Full article

This study investigates the dynamics of thermal plumes interacting with the liquid–air interface in straight-chain alcohols and their mixtures using a photothermal imaging technique based on thermal lensing. This method enables the indirect measurement of temperature gradients via changes in refractive index caused by localized laser heating. Employing a collimated laser beam, the results show the formation and evolution of cylindrical heated zones and their interactions with the liquid–air interface. The study reveals that, while some alcohols exhibit stable surface behaviors, others demonstrate complex dynamical behaviors, including strong stable steady-state oscillations. The findings contribute to understanding fluid dynamics in molecular liquids near their liquid–air interfaces. Full article

Current liquid crystal (LC) lenses cannot achieve lossless arbitrary movement of the optical axis without mechanical movement. This article designs a novel bottom electrode through simulation and optimization, which forms a special LC lens with an Archimedean spiral electrode, realizing a 3D LC wedge and an arbitrarily movable LC lens. When only the bottom electrode is controlled, it achieves a maximum beam steering angle of 0.164°, which is nearly an order of magnitude larger than the current design. When the top and bottom electrodes are controlled jointly, a 0.164° movement of the lens optical axis is achieved. With focal length varies, the movement of the optical axis ranges from zero to infinity, and the lens surface remains unchanged during movement. The focus can move in a 3D conical area. When the thickness of the LC layer is 30 μm, the fastest response time reaches only 0.635 s, much faster than now. Full article

The Yamal-Nenets Autonomous District, especially the Yamal Peninsula located in the permafrost zone, stores Russia’s largest oil and gas resources. However, development in the area is challenging because of its harsh climate and engineering–geological features. Drilling in oil and gas fields in permafrost faces problems that are fraught with serious accident risks: soil heaving leading to the collapse of wellheads and hole walls, deformation and breakage of casing strings, gas seeps or explosive emissions, etc. In this respect, knowledge of the permafrost’s structure is indispensable to ensure safe geological exploration and petroleum production in high-latitude regions. The extent and structure of permafrost in West Siberia, especially in its northern part (Yamal and Gydan Peninsulas), remain poorly studied. More insights into the permafrost’s structure have been obtained by a precise sTEM survey in the northern Yamal Peninsula. The sTEM soundings were performed in a large oil and gas field where permafrost is subject to natural and anthropogenic impacts, and its degradation, with freezing–thawing fluctuations and frost deformation, poses risks to exploration and development operations, as well as to production infrastructure. The results show that permafrost in the western part of the Yamal geocryological province is continuous laterally but encloses subriver and sublake unfrozen zones (taliks) and lenses of saline liquid material (cryopegs). The total thickness of perennially frozen rocks is 200 m. The rocks below 200 m have negative temperatures but are free from pore ice. Conductive features (<10 Ohm﮲m) traceable to the permafrost base may represent faults that act as pathways for water and gas fluids and, thus, can cause a geohazard in the oil and gas fields (explosion of frost mounds, gas blow during shallow drilling, etc.). Full article

Building-integrated photovoltaic (BIPV) glazing systems with intelligent window technologies enhance building energy efficiency by generating electricity and managing daylighting. This study explores advanced BIPV glazing, focusing on building-integrated concentrating photovoltaic (BICPV) systems. BICPV integrates concentrating optics, such as holographic films, luminescent solar concentrators (LSC), Fresnel lenses, and compound parabolic concentrators (CPCs), with photovoltaic cells. Notable results include achieving 17.9% electrical efficiency using cylindrical holographic optical elements and crystalline silicon cells at a 3.5× concentration ratio. Dielectric CPCs showed 97.7% angular acceptance efficiency in simulations and 94.4% experimentally, increasing short-circuit current and maximum power by 87.0% and 96.6%, respectively, across 0° to 85° incidence angles. Thermochromic hydrogels and thermotropic smart glazing systems demonstrated significant HVAC energy savings. Large-area 1 m² PNIPAm-based thermotropic window outperformed conventional double glazing in Singapore. The thermotropic parallel slat transparent insulation material (TT PS-TIM) improved energy efficiency by up to 21.5% compared to double glazing in climates like London and Rome. Emerging dynamic glazing technologies combine BIPV with smart functions, balancing transparency and efficiency. Photothermally controlled methylammonium lead iodide PV windows achieved 68% visible light transmission, 11.3% power conversion efficiency, and quick switching in under 3 min. Polymer-dispersed liquid crystal smart windows provided 41–68% visible transmission with self-powered operation. Full article