Blue-violet Light Research Articles

Prevention of Sunlight-Induced Cell Damage by Selective Blue-Violet-Light-Filtering Lenses in A2E-Loaded Retinal Pigment Epithelial Cells.

Blue light accelerates retinal aging. Previous studies have indicated that wavelengths between 400 and 455 nm are most harmful to aging retinal pigment epithelia (RPE). This study explored whether filtering these wavelengths can protect cells exposed to broad sunlight. Primary porcine RPE cells loaded with 20 µM A2E were exposed to emulated sunlight filtered through eye media at 1.8 mW/cm2 for 18 h. Filters selectively filtering out light over 400-455 nm and a dark-yellow filter were interposed. Cell damage was measured by apoptosis, hydrogen peroxide (H2O2) production, and mitochondrial membrane potential (MMP). Sunlight exposure increased apoptosis by 2.7-fold and H2O2 by 4.8-fold, and halved MMP compared to darkness. Eye Protect SystemTM (EPS) technology, filtering out 25% of wavelengths over 400-455 nm, reduced apoptosis by 44% and H2O2 by 29%. The Multilayer Optical Film (MOF), at 80% of light filtered, reduced apoptosis by 91% and H2O2 by 69%, and increased MMP by 73%, overpassing the dark-yellow filter. Photoprotection increased almost linearly with blue-violet light filtering (400-455 nm) but not with total blue filtering (400-500 nm). Selective filters filtering out 25% (EPS) to 80% (MOF) of blue-violet light offer substantial protection without affecting perception or non-visual functions, making them promising for preventing light-induced retinal damage with aesthetic acceptance for permanent wear.

Irradiation for improving Violet-Blue Light Contribution of tri- and Polychromatic Polysulfone Host-guest systems

Herein, we explored the effect of light irradiation on polysulfone films dopped with highly emissive guests. We report irradiation promoted interactions in a polysulfone membrane functionalized with a fluorinated β-diketone species leading to an improved Violet-Blue Light Contribution in Polychromatic Polysulfone Host-Guest Systems.We suggest that irradiation at higher UV wavelengths, leads to an amorphous-to-monomer phase transformation of the fluorinated boron guest, BF2dbm (dbm as dibenzoylmethanoate), to which corresponds conversion of part of the green emission from aggregates to cyan-blue fluorescence, characteristic of the monomeric form. Also, irradiation at lower wavelength promotes host-guest BF2dbm@PSU strong interaction giving rise to increased emission in the violet-blue region by sacrificing the contribution from the intense blue-cyan emission from BF2dbm molecules.In the current work we also prepared combinations of Tb3+ and Eu3+ highly fluorinated complexes and evaluated its tuneable emission due to light driven ligand interaction with host matrix. The judicious choice of molecular ratio between Tb3+ and Eu3+ complexes allow rationally designed preparation of triple-emissive flexible films when irradiated at 300, 320 and 330 nm, to be used in highly advanced anti-counterfeiting technologies.In short, we propose a simple and new powerful approach for emission colour tuning of polysulfone dopped films.

NIR-triggered NO production combined with photodynamic therapy for tumor treatment

Photodynamic therapy (PDT), as one of the most promising cancer therapy methods, is still limited by several drawbacks, such as tissue hypoxia and shallow light penetration of blue-violet light (200–450 nm), and red light (750 nm) is more penetrating to tissues than blue-violet light, but still lower than near-red light (750–1350 nm). Therefore, we proposed a synergistic therapy system by combining the near-infrared light-triggered PDT with nitric oxide (NO)-based gas therapy to enhance the anti-tumor effects. Upconversion nanoparticles (UCNPs) were loaded with the photosensitizers of ZnPc and the NO donors of l-arginine (L-Arg) to obtain the nanocomposites of UCN@mSiO2@ZnPc@L-Arg. Under 980 nm laser irradiation, reactive oxygen species (ROS) could be produced for PDT and react with l-Arg to produce NO, which is previously reported to have a greater killing effect on tumor cells than ROS and also plays an important role in promoting PDT in our study. Both the in vitro and in vivo tests demonstrated that the combined therapy of PDT with NO therapy could enhance the tumor killing effect significantly compared with the unique application of PDT. The UCNPs-based nanocomposites are expected to be widely used in biomedicine for tumor inhibition.

Decontamination of patient bathroom surfaces with 405 nm violet-blue light irradiation in a real-life setting

Irradiation with violet-blue light (VBL), in the spectrum of 405-450 nm, has been reported to be effective against pathogenic bacteria. The aim of the present study was to investigate if VBL irradiation could reduce the level of surface contamination at seven shared patient's bathrooms in two wards at a hospital in Sweden. Repeated sampling of five separate surfaces (door handle, tap water handle, floor, toilet seat and toilet armrest) was performed in the bathrooms where 405 nm light-emitting diode spotlights had been installed. A prospective study with a cross-over design was carried out, which included two study periods, first with the spotlights either switched on or off and a second study period with the opposite spotlight status. In total, 665 surface samples were collected during the study (133 samples per surface). Bacterial growth were found in 84 % of all samples. The most common findings were CoNS and Bacillus spp. The median cfu/cm2 was 15 (IQR 5-40) for all surfaces. In our main outcome, mean cfu/cm2 of all surfaces in a bathroom, no difference was observed with or without VBL. Clean surfaces (<5 cfu/cm2) were more commonly observed in bathrooms with VBL, also when controlling for confounding factors. No difference was observed in number of heavily contaminated surfaces. We could not safely demonstrate an additive effect on bacterial surface levels when adding VBL to routine cleaning in shared patient bathrooms.

Geometrical, elastic, electronic, phonon, and optical properties of Na3AgO2 from first-principles calculation

In this paper, the geometrical, elastic, electronic, phonon, and optical properties of Na3AgO2 have been systematically studied by first-principles calculation. The results show that Na3AgO2 is mechanically stable and has small compressibility. Na3AgO2 is an indirect band-gap semiconductor with weak interatomic interaction. The bandgap calculated by HSE06 is 2.314 eV, and that calculated by GGA is 1.261 eV. For Na3AgO2, in the valence band near the Fermi level, the curve peaks of TDOS at −2.11 eV and −0.885 eV are primarily composed of O 2p states, which hybridize the 4 d and 4p states of Ag. The conduction band mainly consists of the 4p, 4 d, and 5s states of Ag, while hybridizing a few 2p states of O and a few 2p and 3s states of Na. As can be seen from the phonon dispersion spectrum there is no negative phonon frequency in the whole Brillouin region, indicating the structure is stable. Mulliken bond population of Na3AgO2 shows that O–Ag bonds have strong covalency, O–Na bonds have strong ionic properties, Na–Na bonds and Na–Ag bonds are antibonding. Na3AgO2 has a small reflectivity and a small absorption coefficient in the direction of (100) and (010) and has good transparency. The transparency of blue-violet light in the (001) direction is not as good as that of low-energy visible light. The obtained results lead to the conclusion that Na3AgO2 is a promising p-type transparent conducting material and is expected to be applied in practice.

Current and Ongoing Developments in Targeting Clostridioides difficile Infection and Recurrence

Clostridioides difficile is a Gram-positive, spore-forming anaerobic bacterial pathogen that causes severe gastrointestinal infection in humans. This review provides background information on C. difficile infection and the pathogenesis and toxigenicity of C. difficile. The risk factors, causes, and the problem of recurrence of disease and current therapeutic treatments are also discussed. Recent therapeutic developments are reviewed including small molecules that inhibit toxin formation, disrupt the cell membrane, inhibit the sporulation process, and activate the host immune system in cells. Other treatments discussed include faecal microbiota treatment, antibody-based immunotherapies, probiotics, vaccines, and violet-blue light disinfection.

Polyvinyl alcohol covalently grafted perylene imide for high-performance light-conversion film

To suppress the aggregation caused quenching of perylene diimide (PDI) derivatives, and improve photostability of PDI derivatives, a polyvinyl alcohol grafted copolymer (PVA-PDIE) was prepared by transesterification of a perylene imide derivative (PDIE) and polyvinyl alcohol (PVA). PDIE was characterized by H-NMR and HR-MS, and PVA-PDIE was confirmed by IR, water resistance, and control experiments. PVA-PDIE film showed high quantum yield (0.75), and matching emission maxima (620 nm). More importantly, PVA-PDIE film had excellent thermal stability and photostability, high transmittance and light conversion quality. Furthermore, the decomposition temperature of PVA-PDIE film was up to 240 °C, while emission intensity maintained at 95 % and 96 % of the initial value in turn after intensified ultraviolet radiation of 40 h and sunlight radiation of 40 days. Compared with the PVA blank film, photosynthetic photon flux density (PFD) of PVA-PDIE film increased by 25 % and 34 % for red orange light and near-infrared light respectively, and decreased by 39 %, 27 %, and 24 % for ultraviolet light, blue violet light, and yellow-green light in sequence, indicating outstanding light conversion performance. Meanwhile, PVA-PDIE film had excellent transparency.

A handheld device for intra-cavity and ex vivo fluorescence imaging of breast conserving surgery margins with 5-aminolevulinic acid

BackgroundVisualization of cancer during breast conserving surgery (BCS) remains challenging; the BCS reoperation rate is reported to be 20-70% of patients. An urgent clinical need exists for real-time intraoperative visualization of breast carcinomas during BCS. We previously demonstrated the ability of a prototype imaging device to identify breast carcinoma in excised surgical specimens following 5-aminolevulinic acid (5-ALA) administration. However, this prototype device was not designed to image the surgical cavity for remaining carcinoma after the excised lumpectomy specimen is removed. A new handheld fluorescence (FL) imaging prototype device, designed to image both excised specimens and within the surgical cavity, was assessed in a clinical trial to evaluate its clinical utility for first-in-human, real-time intraoperative imaging during index BCS.ResultsThe imaging device combines consumer-grade imaging sensory technology with miniature light-emitting diodes (LEDs) and multiband optical filtering to capture high-resolution white light (WL) and FL digital images and videos. The technology allows for visualization of protoporphyrin IX (PpIX), which fluoresces red when excited by violet-blue light. To date, n=17\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$n = 17$$\\end{document} patients have received 20mgkg\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$20\\frac{\ ext {mg}}{\ extrm{kg}}$$\\end{document} bodyweight (BW) 5-ALA orally 2-4 h before imaging to facilitate the accumulation of PpIX within tumour cells. Tissue types were identified based on their colour appearance. Breast tumours in sectioned lumpectomies appeared red, which contrasted against the green connective tissues and orange-brown adipose tissues. In addition, ductal carcinoma in situ (DCIS) that was missed during intraoperative standard of care was identified at the surgical margin at <1 mm depth. In addition, artifacts due to the surgical drape, illumination, and blood within the surgical cavity were discovered.ConclusionsThis study has demonstrated the detection of a grossly occult positive margin intraoperatively. Artifacts from imaging within the surgical cavity have been identified, and potential mitigations have been proposed.Trial RegistrationClinicalTrials.gov Identifier: NCT01837225 (Trial start date is September 2010. It was registered to ClinicalTrials.gov retrospectively on April 23, 2013, then later updated on April 9, 2020, to reflect the introduction of the new imaging device.)

Enhanced antimicrobial efficacy and energy efficiency of low irradiance 405-nm light for bacterial decontamination

Due to its increased safety over ultraviolet light, there is interest in the development of antimicrobial violet-blue light technologies for infection control applications. To ensure compatibility with exposed materials and tissue, the light irradiances and dose regimes used must be suitable for the target application. This study investigates the antimicrobial dose responses and germicidal efficiency of 405 nm violet-blue light when applied at a range of irradiance levels, for inactivation of surface-seeded and suspended bacteria. Bacteria were seeded onto agar surfaces (101–108 CFUplate−1) or suspended in PBS (103–109 CFUmL−1) and exposed to increasing doses of 405-nm light (≤ 288 Jcm−2) using various irradiances (0.5–150 mWcm−2), with susceptibility at equivalent light doses compared. Bacterial reductions ≥ 96% were demonstrated in all cases for lower irradiance (≤ 5 mWcm−2) exposures. Comparisons indicated, on a per unit dose basis, that significantly lower doses were required for significant reductions of all species when exposed at lower irradiances: 3–30 Jcm−2/0.5 mWcm−2 compared to 9–75 Jcm−2/50 mWcm−2 for low cell density (102 CFUplate−1) surface exposures and 22.5 Jcm−2/5 mWcm−2 compared to 67.5 Jcm−2/150 mWcm−2 for low density (103 CFUmL−1) liquid exposures (P ≤ 0.05). Similar patterns were observed at higher densities, excluding S. aureus exposed at 109 CFUmL−1, suggesting bacterial density at predictable levels has minimal influence on decontamination efficacy. This study provides fundamental evidence of the greater energy efficacy of 405-nm light for inactivation of clinically-significant pathogens when lower irradiances are employed, further supporting its relevance for practical decontamination applications.

Human platelet concentrates treated with microbicidal 405 nm light retain hemostasis activity

Chemical and UV light-based pathogen reduction technologies are currently in use for human platelet concentrates (PCs) to enhance safety from transfusion-transmitted infections. Relative to UV light, 405 nm violet-blue light in the visible spectrum is known to be less harmful. Hence, in this report for the first time, we have assessed the global hemostasis activity of PCs stored in plasma and the activities of six plasma coagulation factors (CFs) as a measure of in vitro hemostatic activity following exposure to the microbicidal 405 nm light. Apheresis PC samples collected from each screened human donor (n = 22) were used for testing of PCs and platelet poor plasma (PPP). Both PCs and PPPs were treated for 5 h with 405 nm light to achieve a previously established microbicidal light dose of 270 J/cm2. Activated partial thromboplastin time and prothrombin time-based potency assays using a coagulation analyzer and hemostatic capacity via Thromboelastography were analyzed. Thromboelastography analysis of the light-treated PCs and plasma present in the PCs showed little difference between the treated and untreated samples. Further, plasma present in the PCs during the light treatment demonstrated a better stability in potency assays for several coagulation factors compared to the plasma alone prepared from PCs first and subjected to the light treatment separately. Overall, PCs stored in plasma treated with 405 nm violet-blue light retain activity for hemostasis.

Synthesis of near-infrared-activated YF3:Yb3+, Tm3+/Bi2MoO6 upconversion photocatalytic materials for the photocatalytic degradation of antibiotics based on fluorescence resonance energy transfer

Photocatalytic degradation of pollutants, an ecofriendly technology, is widely used for environmental remediation. However, the design and synthesis of photocatalytic materials for near-infrared light photocatalysis are challenging. In this study, an upconversion photocatalyst with fluorescence resonance energy transfer (FRET), YF3:Yb3+, Tm3+/Bi2MoO6 (YFYT/BMO), was developed and synthesised based on rare-earth upconversion luminescence. YFYT converted near-infrared (NIR) light into blue–violet light via upconversion. The rapid decay of the fluorescence lifetime of YFYT/BMO at 478 nm (Tm3+:1G4-3H6) verified that FRET efficiently occurred between YFYT and BMO. The degradation rate of tetracycline by YFYT/BMO was 2.6 times higher than that by BMO under NIR light. A great enhancement of 42.1 % on the tetracycline degradation efficiency was achieved in YFYT/BMO compared with pure BMO within 90 min of visible-NIR irradiation. This study provides a basis for developing and designing rare-earth upconversion photocatalytic materials that can achieve excellent photocatalytic degradation of antibiotics using NIR light for environmental remediation.

Structural and optical properties of position-controlled n-ZnO nanowire arrays: Potential applications in optoelectronics

Highly position-controlled ZnO nanowire (NW) arrays and nanowire-cluster (NW–C) arrays are grown on mask-patterned gallium nitride (GaN) substrates by hydrothermal method. Electroluminescence (EL) emissions with blue-violet light at forward-bias(fb) voltage, EL emissions with yellow light at reverse-bias(rb) voltage, and EL emission at both rb voltages and rb voltages were achieved by the adjustment of the size of the heterojunction interface between wire arrays and film. The high rb current is attributed to electron tunneling transport edge effect via a narrow tunnel barrier. The obtained results highlight that the EL characteristics of ZnO NWs can be tuned and controlled through the size of the heterojunction interface between wire arrays and film. Besides, the nonplanar heterogeneous structure of ZnO NW arrays/GaN film also shown a great spectral response characteristic in the ultraviolet(UV) band, which proves that the structure of is worthy of being studied to achieve high performance UV photodetectors.

Photoreactivity of polycyclic aromatic hydrocarbons (PAHs) and their mechanisms of phototoxicity against human immortalized keratinocytes (HaCaT)

Polycyclic aromatic hydrocarbons (PAHs) are ubiquitous organic compounds in the environment. They are produced by many anthropogenic sources of different origins and are known for their toxicity, carcinogenicity, and mutagenicity. Sixteen PAHs have been identified as Priority Pollutants by the US EPA, which are often associated with particulate matter, facilitating their dispersion through air and water. When human skin is exposed to PAHs, it might occur simultaneously with solar radiation, potentially leading to phototoxic effects. Phototoxic mechanisms involve the generation of singlet oxygen and reactive oxygen species, DNA damage under specific light wavelengths, and the formation of charge transfer complexes. Despite predictions of phototoxic properties for some PAHs, there remains a paucity of experimental data. This study examined the photoreactive and phototoxic properties of the 16 PAHs enlisted in the Priority Pollutants list. Examined PAHs efficiently photogenerated singlet oxygen and superoxide anion in simple solutions. Furthermore, singlet oxygen phosphorescence was detected in PAH-loaded HaCaT cells. Phototoxicity against human keratinocytes was evaluated using various assays. At 5 nM concentration, examined PAHs significantly reduced viability and mitochondrial membrane potential of HaCaT cells following the exposure to solar simulated light. Analyzed compounds induced a substantial peroxidation of cellular proteins after light treatment. The results revealed that a majority of the examined PAHs exhibited substantial reactive oxygen species photoproduction under UVA and violet-blue light, with their phototoxicity corresponding to their photoreactive properties. These findings improve our comprehension of the interactions between PAHs and human skin cells under environmental conditions, particularly when exposed to solar radiation.

Laser-enabled dual-state transformation on PANI:PSS/Si for wavelength-selective detection

Position-sensitive detectors are widely used in industry due to accurate sensing of changes in light position. The introduction of additional wavelength selectors can cause deviations in light position and affect the performance of the devices. In this work, an organic–inorganic heterojunction of polyaniline-poly (p-styrenesulfonic acid) (PANI:PSS)/p-Si is proposed to achieve selective detection at optical wavelengths using the lateral photovoltaic effect. The maximum reduction of sensitivity in the detection of 405 nm laser can reach up to 127.59 mV/mm, with a decrease in about 99%. When the device is exposed to blue-violet light, the absorption layer changes from a Si layer to a PANI:PSS layer, which weakens the photon utilization efficiency and charges carrier transport. The self-generated longitudinal voltage further enhances the absorption of the PANI:PSS layer for blue-violet light. PANI absorbs photon energy to generate electron–hole pairs and transitions from the reduced state to the oxidized state in the depletion region at the contact interface. The oxide layer hinders carrier separation and increases carrier recombination. Due to the inherent properties of the structure, the wavelength selection function is realized by the detector itself, enriching its original single function. The sensitivity in other light bands has been improved, including more than three times at 520 nm compared to p-Si. These results have provided the theoretical foundation for highly selective and tunable optoelectronic devices while helping to overcome the challenges of high manufacturing costs and customized application scenarios. They provide a viable solution for the intelligent development of optoelectronic devices.

The effect of photolysis of sodium citrate treated with gold chloride using coloured light on the generation of gold nanoparticles and the repression of WiDr colon cancer cells

Gold nanoparticles (GNPs) are usually formed via a wet chemical method using gold (III) chloride trihydrate (GC), which is treated with stable reducing agents such as sodium citrate (SC). This study determines the effect of coloured light on the formation of GNPs by irradiation of SC after the addition of GC (SCGC) and the effect of the SCGC photolytic procedure on the suppression of WiDr colon cancer cells by forming reactive oxygen species. The absorbance of surface plasmon resonance peaks at 523 nm are 0.069 and 0.219 for SCGC when treated with blue light illumination (BLI) and violet light irradiation (VLI), respectively, whereas green and red light treatments have little or no effect. Most GNPs have diameters ranging from 3 to 15 nm, with a mean of 6 nm, when SCGC is exposed to VLI for 1.5 h. Anionic superoxide radicals (O2•−) are formed in a charge-transfer process after SCGC under VLI treatment; however, BLI treatment produces no significant reaction. Moreover, SCGC under VLI treatment proves to be considerably more effective at inhibiting WiDr cells than BLI treatment, as firstly reported in this study. The reduction rates for WiDr cells treated with SCGC under BLI and VLI at an intensity of 2.0 mW/cm2 for 1.5 h (energy dose, 10.8 J/cm2) are 4.1% and 57.7%, respectively. The suppression rates for WiDr cells treated with SCGC are inhibited in an irradiance-dependent manner, the inhibition percentages being 57.7%, 63.3%, and 80.2% achieved at VLI intensities of 2.0, 4.0, and 6.0 mW/cm2 for 1.5 h, respectively. Propidium iodide is a fluorescent dye that detects DNA changes after cell death. The number of propidium iodide-positive nuclei significantly increases in WiDr cells treated with SCGC under VLI, suggesting that SCGC photolysis under VLI is a potential treatment option for the photodynamic therapy process.

Fabrication of Robust Carbon Dots Containing Coatings with UV-Shielding, Light Conversion, and Antifogging Multiple Functions.

Although a wide variety of single-function coatings have been successfully developed, the integration of multiple functions onto a single coating has remained an immense challenge in the field. Here, we report a simple room-temperature fabrication of robust coatings with UV-shielding, light conversion, and antifogging functionalities. The addition of glutaraldehyde (GA) molecular cross-linker and carbon dot (CD) nanocross-linker with light conversion function to poly(vinyl alcohol) (PVA) resulted in the formation of robust spatial structures of coatings. The fluorescence intensity tests demonstrated that the coatings had an excellent ability to absorb and convert ultraviolet light into blue-violet light. Both cold-warm and hot-vapor tests showed that the coatings had excellent antifogging performance. To our surprise, no creases were observed after coatings were immersed in water for 1 month, indicating that these are much stronger than those reported so far. The 8H pencil hardness and wear resistance attested to their excellent mechanical properties. The current preparation method can be operated at ambient temperature and is not restricted by the substrate type and shape. Therefore, it may also expand the possibilities for future applications of coatings for glass windows, optical microscopes, eyeglasses, agricultural greenhouses, and so on.

The potential role of violet-blue light to preventing hospital acquired infections: a systematic review.

The potential role of violet-blue light to preventing hospital acquired infections: a systematic review.

Blue-Violet Light-Blocking Eye Protectors in Dental Practice: A Preliminary Study

Healthcare professionals are exposed to various intense light sources during dental practice. Of particular concern is blueviolet light (wavelength 380-500 nm), which can impact retinal health, necessitating effective mitigation strategies. In this study, we assessed the practical utility of lenses designed to reduce blue-violet light to wavelengths of approximately 420 nm or shorter within the dental practice setting. Two dentists and four dental hygienists participated in the study. The participants wore either blue-light-reducing lenses or lenses with no effect for one month. The degree of eye strain was evaluated using flicker values. The results revealed that four of the six participants experienced reduced eye strain while wearing blue-violet light-reducing lenses. In conclusion, this study addresses the acknowledged impact of blue-violet light on retinal health. However, the long-term prognosis remains uncertain. Therefore, considering the potential unknown effects, it is necessary to discuss the use of blue-violet light-cut lenses in everyday practice as a risk-management strategy.

Simulating skylight polarization patterns using the backward Markov Chain Monte Carlo method

Skylight polarization patterns provide valuable information for atmospheric measurements, polarized remote sensing and navigation applications. However, efficiently and accurately modeling polarized radiative transfer in atmospheric scattering remains challenging. We propose a backward Markov chain Monte Carlo (B-MCMC) method to simulate skylight polarization patterns by constructing a Markov chain in parameter space to track photons from the sensor to the top-of-atmosphere (TOA). The results show that the B-MCMC model significantly improves the computational efficiency by a factor of 8-10 while retaining the computational accuracy compared with Monte Carlo simulations. The experiments show that in cloudy skies, the skylight polarization pattern is generally weakened, in the field of skylight polarization detection and application, long wavelengths should be used in clear weather and blue-violet light should be used in cloudy weather, which corresponds to a larger degree of polarization (DOP) and facilitates the acquisition of polarization information. Finally, the aerosol optical depth (AOD) has an important effect on the skylight polarization, as the AOD increases, the DOP decreases, and the decreasing trend will be more and more obvious, when the AOD is above 0.3, the maximum DOP will not exceed 0.5, which is verified by the division of focal plane (DOFP) polarization measurement device.

Synthesis and photoluminescence properties of single-phase Sr3B14O24:RE3+ (RE = Ce, Tb, Sm, Eu) phosphors and glass for WLEDs, UV and NIR shielding

Commercial white light-emitting diodes (WLEDs) usually face problems such as lack of red emission, color difference caused by different degradation rates of multiphase phosphors and the poor thermal stability of the organic encapsulants. The development of new single-phase phosphors and glass can solve these problems well. Sr3B14O24:RE3+ (RE = Ce, Tb, Sm, Eu) phosphors and glass were synthesized by solid-phase method. The obtained Sr3B14O24:RE3+ (RE = Ce, Tb, Sm, Eu) samples showed multicolor emission including blue, green, orange and red, respectively. The optimal excitation wavelength of these samples was located in the blue or ultraviolet (UV) light regions, which were well matched with the blue-violet light chips to manufacture WLEDs. More interestingly, UV absorption was found in Sr3B14O24:Ce3+/4+ glass samples. The doping of dual-valence cerium ions could enhance the shielding performance in the light of inferences drawn from the UV-Vis absorption and transmission spectra of glass samples. By co-doping different concentrations of Cs+ ions in Sr3B14O24:Ce3+/4+ glass samples, the function of near infrared (NIR) shielding was also realized. As a new optical multifunctional material, rare earth doped Sr3B14O24 have great potential for application in WLEDs, UV and NIR shielding.