Light Transmission Properties Research Articles

Asynchronous topological phase transition in trimer lattices

We propose a model of a non-reciprocal double-layer trimer photonic lattice. In this model, two types of topological phases are presented. By adjusting the imaginary coupling coefficients and intra-cell coupling coefficients in this model, two topological phases appear in different coefficient ranges. They exhibit asynchronous topological phase transitions as the coupling coefficients change. We discover that these asynchronous topological phase transitions can impact the light transmission properties of the system. When the coupling coefficients are adjusted to put the system in a topologically non-trivial state, the injected light beam tends to localize at the edge. Moreover, before and after the phase transition, the lowest energy band exhibits oscillatory and non-oscillatory behavior in the evolution of the light beam at the boundary. Asynchronous topological phase transitions can be utilized to manipulate the light transmission properties of the system, offering potential applications in optical communication and the development of photonic integrated circuits.

Natural polymer fillers instead of dye and pigments: Pumice and scoria in PDMS fluid and elastomer composites

Abstract The electrical and thermal conductivities and light transmittance properties of silicone oil and polydimethylsiloxane (PDMS) elastomer composites were investigated. Pumice, scoria, nano-Ag, and multi-walled carbon nanotube (MWCNT) particles were used as fillers. An effective, clean, and easy method was used to prepare nanosized particles from pumice and scoria rocks. Only MWCNT–PDMS composites showed electrical conductivity. The highest electrical conductivity of 24.7 S·m−1 was obtained with the 25% pumice–10% MWCNT–silicone oil composite. All filler particles increased the thermal conductivity of the PDMS elastomer. MWCNTs were more effective than pumice and scoria, and the thermal conductivity reached 0.62 W·(m·K)−1 with an addition of 3 wt% MWCNTs. All filler particles decreased the transparency of the PDMS elastomer. The sample with 5 wt% pumice particles reached zero transmittance. Pumice and scoria naturally colored the PDMS elastomer. The powders of these natural volcanic rocks could be used as a suitable coloring filling material instead of dyes and pigments for polymers without waste. However, it was concluded that pumice and scoria particles are not suitable for making composites with silicone oil due to the possibility of catalyzing the degradation of linear PDSM.

Investigation of the Efficacy of Horizontal Hollow Light Tubes for Energy Conservation in Illuminating Buildings

This study investigates the properties of light transmission and distribution, examining how incident light angles impact illuminance distribution and daylight factor. Light tubes are acknowledged as promising tools to enhance lighting conditions and reduce energy consumption in building design. The study involved installing horizontal hollow light tubes, each measuring 0.5 m in length and 0.30 m in diameter, on a wooden test model. A 20-watt LED lamp was employed as the light source, and an illuminance meter recorded the values at various horizontal and elevation angles. The study’s assessment included calculating the average illuminance and daylight factor to obtain light transmission efficiency and energy-saving potential. The findings revealed that both aluminum alloy and zinc alloy tubes experienced a decrease in illuminance as incident elevation angles increased, with the most effective light transmission occurring at a horizontal angle of 90°. Notably, the aluminum alloy tube outperformed the zinc alloy tube, demonstrating more than a 15% increase in light transmission efficiency. Furthermore, the daylight factor values from both types of tubes aligned with established standards for residential and office activities, underscoring their potential as energy-efficient lighting solutions for spaces lacking natural light or with limited illumination.

A Comparative Thermodynamic Study of AlF3, ScF3, Al0.5Sc0.5F3, and In0.5Sc0.5F3 for Optical Coatings: A Computational Study

Optical coatings are thin layers of materials applied to optical components in order to modify the transmission, reflection, or polarization properties of light. The common materials used for optical coatings include magnesium fluoride (MgF2), scandium trifluoride (ScF3), and aluminum trifluoride (AlF3), owing to their desirable optical properties, spectral range, and compatibility with substrates. However, each of these materials has its own drawbacks. For instance, AlF3 has been found to exhibit limited resistance to attack by chemicals, as well as poor thermal stability, while MgF2 has low durability, as well as being hygroscopic. In this study, we undertook ab initio calculations in order to compare the thermal properties of AlF3, ScF3, Al0.5Sc0.5F3, and In0.5Sc0.5F3 in order to obtain the best material for optical coatings. MgF2 was also included in the study as a reference. The calculations used PBE pseudopotentials and the extended generalized gradient approximation within the quantum espresso algorithm. The study demonstrated that the computed results agree with the information found in the literature. ScF3 exhibited a negative coefficient of thermal expansion, unlike the other four. Moreover, AlF3 was found to be the best candidate for optical coatings that are used in high-power laser systems with high thermal dissipation, due to its superior thermal expansion coefficient as well as its better response to thermal stress. The large variation between the cp and cv of ScF3 is not desirable. Moreover, due to its negative thermal expansion coefficient, ScF3 is not thermally stable. The highest thermal stability was exhibited by In0.5Sc0.5F3. Since Al0.5Sc0.5F3 and In0.5Sc0.5F3 have been modeled in this study for the first time, experimental determination of their crystal structures needs to be investigated.

Preparation and characterization of egg white protein film incorporated with epigallocatechin gallate and its application on pork preservation.

The aim of this study was to develop the composite films with antioxidant and biodegradable activity based on egg white protein (EWP) and epigallocatechin gallate (EGCG). Water susceptibility, light transmittance, microstructure and antioxidant properties of the composite films without and with EGCG were fully characterized. It was noted that the addition of EGCG might decrease the moisture content, water solubility and swelling capacity. SEM micrographs revealed that discontinuous blocks and rough surfaces were caused by increasing concentration of EGCG, whereas compact and homogeneous particles appeared when the concentration of EGCG reached to 80μmol/L. Moreover, the biodegradability of the composite films was demonstrated by the soil degradation properties that they can be almost completely degraded within ten days. Experimental results on the application in chilled fresh pork showed that the EWP-based films could play an antioxidant role when incorporated with EGCG, indicating their great potential for food packaging.

Polymer and photo‐selective covers on plant and fruit development: A review

AbstractGrowers have increasingly adopted protected cropping in tunnels or greenhouses to ensure sustainability and continuous crop productivity against a backdrop of climate change. The predominant types of covers used in controlled‐environment agriculture are polymer‐based shade nets or structures covered with polymer sheets. These have three main functions: (1) physical protection from birds, hail, and excessive radiation; (2) modification of the environment by controlling humidity, shade, and temperature; and (3) increasing the proportion of diffuse light. In order to address concerns regarding the amounts of useful light potentially blocked by these covers, researchers and growers have suggested several innovative solutions that involve altering the light received by plants. This includes supplementation of artificial illumination, filtering solar radiation with colored films, or altering the incident spectrum with spectral‐shifting covers containing light‐emitting fluorescent compounds embedded within a polymer matrix. In principle, any of these methods have the potential to selectively modify the spectrum of incident light and subsequently induce plant physiological responses, resulting in increased crop yield, improved fruit quality, and reduced susceptibility to pests and diseases. This review focuses on the benefits offered by passive covers in terms of their variable shading and light transmittance properties and their effects on vegetative growth and fruit development in various crops. It is anticipated that through a better understanding of photo‐selective covers in protected cropping, primary producers will be better equipped to make informed decisions regarding their deployment and thereby achieve better yields and more nutritious produce from their crops.

A novel active packaging film containing citronella oil: Preparation, characterization, antimicrobial activity and application in grape preservation

In this study, citronella oil (CO) was incorporated into soy protein isolate (SPI) to prepare antimicrobial protein films capable of inhibiting the growth of spoilage microorganisms on food packaging and providing effective preservation of food products. The morphological, physical and functional properties of the antimicrobial protein films were characterized and investigated by different characterization tools. The SEM results showed that the surface of the films was relatively smooth and flat. FTIR and XRD analyses indicated that CO was uniformly distributed in SPI with good compatibility. Under UV light, the films containing CO showed moderate light transmission and better UV-blocking properties than the SPI-based films. The addition of CO improves the hydrophobic property of the films, and the water content of the film containing 3 % CO is reduced to 20 % compared with that of the SPI film with 27.5 %. The DMA showed that the prepared films had good tensile, swelling and relaxation properties. Antimicrobial protein films containing 3 % CO showed high antimicrobial activity against S. aureus and E. coli. It was also found that the film with 3 % CO had a survival rate of more than 70 % and an apoptosis rate of 5.3 % for BEAS-2B cells after 48 h, indicating that such films are safe. Moreover, the film with 3 % CO showed good freshness and storage capacity with a weight loss of 44.16 % after the grapes had been packed for 7 days. These good physical properties and functional properties suggest that films containing CO have great potential for food packaging applications.

Assessment and ANN model development of natural light transmittance of light-transmitting concrete

This study aims to reveal the potential of Light-transmitting concrete (LTC) in transmitting natural light or sunlight, and to investigate the relationship between fibre diameter, fibre spacing, solar incidence angle, surface area, and light transmittance properties. The artificial neural network model as well as explicit equations from the model were developed to predict the light transmittance of LTC. The surface area was altered by varying LTC block arrangements from one to six. It was found that light incidence angle significantly affected the light transmittance of LTC. The highest light transmittance of LTC was achieved near solar noon, but it decreased drastically as soon as the solar incidence angle exceeded the acceptance angle. The effect of the LTC surface area and solar incidence angle on light transmittance diminished with a smaller fibre diameter or larger fibre spacing. The ANN model and explicit equations developed from the network provide good accuracy in predicting light transmittance of LTC.

Synthesis, optimization via response surface methodology, and structural properties of carboxymethylcellulose/curcumin/graphene oxide biocomposite films/coatings for the shelf-life extension of shrimp

In this study, carboxymethylcellulose (CMC), curcumin (Cur), and graphene oxide (GO) were used to prepare a novel biocomposite film (CMC-Cur-GO). A central composite design under response surface methodology was employed to optimize the films in terms of water vapor permeability (WVP) and swelling percentage (SP). Under the optimum conditions, which the rates of CMC, GO and curcumin were found to be 1350 mg, 29.99 mg, and 0.302 g, respectively, WVP and SP of CMC-Cur-GO were obtained 0.902 × 10−8 (g/m·h·Pa) and 13.62 %, respectively. The biocomposite films (CMC, CMC-Cur, CMC-GO and CMC-Cur-GO) were characterized by Fourier transform infrared spectroscopy, field-emission scanning electron microscope, thermal gravimetric analysis, X-ray diffraction analysis, ultraviolet-vis light transmittance, moisture content, and mechanical properties. Compared with pure CMC film, the tensile strength, elongation at break and Young's modulus of CMC-Cur-GO were significantly improved by up to 75 %, 41 % and 23 %, respectively (p < 0.05). Then, CMC-Cur-GO was applied as a coating solution for the shrimps. The coated shrimps with the CMC-Cur-GO significantly (p < 0.05) showed a noteworthy improvement in microbial quality (total and psychrotrophic bacterial count), chemical deterioration and lipid oxidation (pH and total volatile basic nitrogen, peroxide value and thiobarbituric acid) and physical characteristic (weight loss) as compared to other samples. The CMC-Cur-GO coating could increase the shelf life of shrimp under refrigerated storage.

Study on optical coupling characteristics of a high-radial-tolerance thick-lens beam expanding fiber collimator

In this paper, a high-radial-tolerance fiber collimator (HRTFC) consisting of beam expanding fiber (BEF) and thick-lens (T-lens) is designed. The HRTFC uses BEF to reduce coupling loss, while T-lens are used to increase the outgoing spot to enhance the tolerance of radial mismatch. Firstly, the Gaussian beam ABCD optical transmission matrix is used to analyze transmission properties of light in the T-lens. Then, a beam transmission coupling model is constructed to explore the coupling losses of radial, angular, and axial mismatches under different spots. Finally, a static experimental platform is built to verify the influence of spot size on the coupling mismatch, and a dynamic experimental platform is built to monitor the temperature without contact. The experimental results show that the coupling loss decreases from 1.808 dB to 0.368 dB in the HRTFC, with the fiber mode field diameter (MFD) increasing from 10μm to 28μm. Increasing the spot of the HRTFC to a certain extent can reduce the tolerance of angular mismatch but can significantly increase the tolerance of radial mismatch.

Natural light transmittance of light-transmitting concrete (LTC) incorporated with optical fibres

This paper focused on investigating the light transmittance properties of light-transmitting concrete (LTC) under sunlight. Self-compacting concrete (SCC) and polymethylmethacrylate (PMMA) optical fibres with fibre diameter of 2 mm were used to fabricate LTC blocks. Since fibre spacing, LTC surface area, and light incidence angle are important factors which affect the light transmittance, but are rarely investigated in previous studies, the current study used fibre spacing of 15 mm, 18.75 mm, and 25 mm, and different LTC surface area, altered by placing one to six blocks together, to investigate the effects on light transmittance of LTC under sunlight. The light transmittance tests were conducted on a sunny day from 9 a.m. to 4p.m. A light meter was used to measure the intensity of light transmitted by the LTC. Fresh properties tests of SCC and compression tests on LTC were also conducted. The results show that LTC incorporated optical fibres had lower compressive strength compared to the control concrete block. The difference in fibre spacing has no significant effect on the compressive strength of LTC. The light transmittance of LTC with a spacing of 15 mm has the best light transmittance performance among the LTC blocks with different fibre spacing. The increment of light transmittance was approximately 24% to 28% near solar noon, when the LTC surface area increased from one block to six blocks regardless of the fibre spacing. It was found that the light transmittance declined drastically when the light incidence angle was beyond the acceptance angle. Further research is needed on LTC that takes into account the distance between the light meter and the LTC block to obtain a more comprehensive understanding of light transmittance before it is applied in building construction, with the aim to reduce light energy consumption.

Tuning energy storage and light transmittance properties in ZrO2-modified Na2O–K2O–Nb2O5–SiO2 glass-ceramics

Crystallization kinetics in ZrO2-modified glass-ceramics, (35-x)Na2O–5K2O–40Nb2O5–20SiO2-xZrO2 (x = 0, 1, 3, 5, 10 mol%), is analyzed by crystallization activation energy Ec and kinetic parameter k. A large kinetic parameter k of 1.657 × 1025 is found for the sample with x = 1, which indicates a high tendency toward crystallization. NaNbO3 is formed as the major phase, and its crystallinity changes significantly by the addition of ZrO2. It is found that the dielectric permittivity and maximum polarization are affected by crystallinity. Large domains are formed, and a relaxation process appears at high frequencies. In addition, the breakdown strength (BDS) is affected by the strong electric field distortion rather than the resistance in this system. Complex impedance analysis shows that resistance decreases with the addition of ZrO2. The electric field distortion of the glass-ceramics is simulated by COMSOL. A low interfacial polarization activation energy Ea of 0.821 eV is achieved by the addition of ZrO2. The maximum pulse power density reaches 90 MW/cc at 350 kV/cm for the sample with x = 10, and the pulse energy density attains 0.91 J/cm3 at 300 kV/cm for the sample with x = 1. Light transmittance is achieved because of the low crystallinity and the disappearance of cristobalite SiO2 in the Na2O–K2O–Nb2O5–SiO2 glass-ceramics.

Transmission and Reflection properties of the incident Light via SW coherent laser field

The relative phase of the applied lights has been used to explore the position dependence of the transmitted and reflected light from a defective dielectric medium. The duplicated two-level atomic system that makes up the dielectric medium interacts with a position-dependent standing wave (SW) coupling light and a weak probe laser field. We found that identical behaviors can be produced for the transmitted and reflected light in various directions due to the relative phase of the applied light. Furthermore, we understood that the transmitted and reflected spectra of the incident light become asymmetric for the asymmetric profile of the coupling light, and that these circumstances will cause the probing field to be amplified. In this instance, we found that altering the relative phase of the applied lights can modify the position of the subluminal and superluminal light.

Construction and In Vitro Evaluation of Collagen/Bioactive Glass Composite Membranes as a Corneal Implant

Collagen (Col), the major component of native cornea, has been extensively employed for constructing corneal repair materials. However, inflammation impacts the process of corneal repair, even leading to transplant failure. Bioactive glass (BG) exhibits an excellent anti-inflammatory effect and immunomodulatory function in soft tissue repair. Herein, in this study, the potential of incorporating BG into collagen-based membranes for corneal repair was explored. BG was incorporated at 1, 5, and 7 wt %. The physicochemical properties of the membranes were determined, and in vitro cell-based analyses were also conducted. The results revealed that the Col-BG membranes exhibited desirable light transmission properties, mechanical properties, and good biocompatibility, which meet the requirements of a corneal substitute. Furthermore, Col membranes with 5 and 7% ratio of BG effectively induced corneal epithelial cell adhesion and migration. The Col-BG membranes displayed anti-inflammatory effects as confirmed via polymerase chain reaction and enzyme-linked immunosorbent assay (ELISA) analysis. Among the different BG concentrations tested, the Col-BG membrane containing 5 wt % BG displayed the most favorable combination of physical and biological properties in vitro. Thus, this study described a corneal repair material and provides evidence regarding the feasibility of using Col-BG membranes for corneal repair.

Enhancement in Some Physical Properties of (PVP: CMC) Blend by the addition of MgO

This research study explores the effects of adding MgO nanoparticles to a polymeric blend composed of 50% PVP and 50% CMC. The blend was prepared using MgO nanoparticles (0.2%, 4%, and 6%) and varying processing conditions. The structural, optical, and electrical properties of the resulting blend were analyzed to determine the impact of the added nanoparticles on the blend's properties. Results showed that the addition of nanoparticles significantly improved the structural, optical, and electrical properties of the polymeric blend. Specifically, the energy gap is 4.224 eV for (PVA: CMC) film and increased to 3.432 eV for (PVA: CMC-6% MgO), the light transmission and reflection properties were enhanced. Additionally, the conductivity of the blend was increased, making it suitable for various applications, including optoelectronics, sensors, and biomedical devices. Overall, this study demonstrates the potential of adding nanoparticles to polymeric blends to improve their properties and highlights the importance of optimizing processing conditions to achieve the desired properties for specific applications.

Effect of filler load on structural coloration and color adjustment potential of resin composites.

The color-matching ability of single-shade composites Omnichroma (OMN) and Omnichroma Flow (OCF) is ensured by structural color, which arises from monodisperse 260 nm spherical fillers. This study evaluated how filler load influences the color adjustment potential of composite restorations to human teeth of various shades. The performance of composites containing the 260 nm spherical fillers -OMN (79 wt%), OCF (71 wt%), and experimental composites R1 (65 wt%), and R2 (60 wt%)- was compared to two conventional A2-shade composites and a transparent composite. Additionally, the translucency parameter, spectral reflectance, and light transmission properties were assessed. Composites with a lower load of the 260 nm spherical fillers exhibited lower light diffusion and lower reflectance in the yellow-to-red range (580-650 nm), which is characteristic for the structural color of OMN and OCF. The best color adjustment was achieved with OCF, presumably due to its high translucency and uniform spectral reflectance.

ECM-Like Adhesive Hydrogel for the Regeneration of Large Corneal Stromal Defects.

The repair of large-diameter corneal stroma defects is a major clinical problem. Although some studies have attempted to use hydrogels to repair corneal damage, most of these hydrogels can only be used for focal stromal defects that are ≤3.5mm in diameter due to poor hydrogel adhesion. Here, a photocurable adhesive hydrogel that mimics the extracellular matrix (ECM) with regard to composition for repairing 6mm-diameter corneal stromal defects in rabbits is investigated. This ECM-like adhesive can be rapidly cured after light exposure, with high light transmittance and good mechanical properties. More importantly, this hydrogel maintains the viability and adhesion of cornea-derived cells and promotes their migration in vitro in 2D and 3D culture environments. Proteomics analysis confirms that the hydrogel promotes cell proliferation and ECM synthesis. Furthermore, in rabbit corneal stromal defect repair experiments, it is proven by histological and proteomic analysis that this hydrogel can effectively promote corneal stroma repair, reduce scar formation, and increase corneal stromal-neural regeneration at the sixmonths follow-up. This work demonstrates the great application of ECM-like adhesive hydrogels for the regeneration of large-diameter corneal defects.

Ultracompact metalens-based beam-focusing fiber-optic device with a large numerical aperture.

Conventional optical fibers have good light conduction and transmission properties, and have been widely used in the fields of long-distance fiber-optic communication and sensing. However, due to the dielectric properties of the fiber core and cladding materials, the spot size of the transmitted light is dispersive, which greatly limits the application areas of optical fiber. The emergence of metalenses based on artificial periodic micro-nanostructures is opening the door to a variety of fiber innovations. We demonstrate an ultracompact beam-focusing fiber-optic device based on a composite structure of a single-mode fiber (SMF), a multimode fiber (MMF), and a metalens consisting of periodic micro-nano silicon column structures. Convergent beams with numerical apertures (NAs) of up to 0.64@air and a focal length of 63.6 μm are produced by the metalens on the MMF end face. The metalens-based fiber-optic beam-focusing device could find new applications in optical imaging, particle capture and manipulation, sensing, and fiber lasers.

Achieving outstanding toughness of PMMA while retaining its strength, stiffness, and transparency using in situ developed TPEE nanofibrils

Poly(methyl methacrylate) (PMMA) is an amorphous thermoplastic with high strength, high stiffness, and excellent light transmittance. However, PMMA is very brittle at room temperature, which limits its ubiquitous applications. In this article, we report a scalable, cost-effective, and environmentally-friendly method for enhancing the toughness of PMMA without sacrificing its strength, stiffness, and transparency. PMMA composites comprising in situ developed nanofibrils of thermoplastic polyester elastomer (TPEE) were fabricated following the established concept of converting instead of adding. Remarkably, even only 1 wt% of TPEE nanofibrils with an average diameter of ∼50 nm provided a ∼255% increment in the toughness and ∼29.2% improvement in the impact strength of PMMA, while still maintaining its strength, stiffness, and transparency. In comparison, when TPEE was dispersed and distributed as spheroids, no toughening effect was observed at 1 wt% of TPEE content, and even 10 wt% of TPEE content provided only a ∼150% increment in the toughness, which was, however, accompanied by a decrease in strength, stiffness, and transparency. Herein, we present the effect of both TPEE structure (spheroids vs nanofibrils) and concentration on the rheological, thermomechanical, light transmittance, and mechanical properties of the PMMA/nanofibril-TPEE composites. Based on the fractography and small-angle X-ray scattering analysis, we propose that nanofibril-induced multiple crazing is one of the major sources of the greatly improved toughness. The composites presented in this article can be used in applications that require unique combinations of high toughness, high strength, high stiffness, and excellent transparency.

Ameliorating Properties of Perovskite and Perovskite–Silicon Tandem Solar Cells via Mesoporous Antireflection Coating Model

AbstractIt is anticipated that perovskite solar cells (PSCs) will overtake other products in the market for next‐generation photovoltaics. The optical loss, however, continues to be a flaw that restricts the photocurrent (Jph) of PSCs. Mesoporous antireflection coatings (ARCs), both monolayer and multilayer, are designed using a combination of the finite element method and equivalent medium theory, and ARCs models are merged with PSCs. In the current work, mesoporous ARCs are made, the optical performance of the device is evaluated using optical modeling, and then the ARCs are integrated into solar cells. The simulation results show that the Jph of planar inverted PSCs can increase to 24.00 mA cm−2 when the front surface of PSCs adopts mesoporous ARC (via parameter optimization and sensible arrangement and combination). An increase of 0.98 mA cm−2 in Jph of PSCs is observed in comparison with flat ARC (23.02 mA cm−2). The strong light transmission and low reflection properties of the mesoporous ARCs are confirmed by the optimized solution. It is important to note that the first fusion of mesoporous and multilayer ARC offers a fresh approach to the development of perovskite and perovskite/silicon tandem solar cells with extremely high efficiency.