High Ultraviolet Transmittance Research Articles

Improving the UV transmittance of synthetic quartz through defect repair methods

Synthetic quartz materials with high ultraviolet transmittance are widely used in lenses and other optical devices. However, the relatively insufficient transmittance limits the application. In this paper, method of Defect Compensation is proposed to reduce the content of ODC, E'center and NBOHC and synthetic quartz glass with UV high transmittance was prepared successfully. The glass has high transmittance with internal transmittance of 99.9%@193nm, low stress birefringence with 0.9nm/cm @632.8nm and good optical homogeneity with 0.78ppm @ 632.8nm.

Synthesis and characterization of high strength and ultraviolet transmitting silicone rubber reinforced by organic solvent‐soluble trimethylsiloxysilicate polymers (MQ and MTQ copolymers)

AbstractAdditional‐type liquid silicone rubber (ALSR) has poor mechanical properties, and conventional methods to reinforce it are at the cost of decreasing transparency. Here, vinyl MQ and fluorine‐containing MTQ silicone resins were synthesized by the sol–gel method. Then, high strength and ultraviolet (UV) transmitting ALSR were prepared using MQ and MTQ silicone resins as reinforcing agents, vinyl‐terminated silicone oil, and polydimethylmethylhydrosiloxane as matrix, respectively. The results show that the enhancement effect of MTQ silicone resin on the mechanical properties of ALSR resin is better than that of MQ silicone resin due to the vinyl content of MTQ silicone resin being higher than that of MQ silicone resin. Compared with pure ALSR, the tensile strength, Young's modulus, and Shore hardness of ALSR with 7 wt% MTQ silicone resin are enhanced by 435%, 127%, and 14%, respectively. The thermal stability of ALSR is slightly increased. The modified silicone rubber also has favorable transparency. Additionally, the MTQ/ALSR composites show higher UV transmittance than MQ/ALSR systems owing to the introduction of fluorine element increasing UV transmittance. The high strength and UV transmittance silicone rubber composites were prepared by using a small addition of MTQ silicone resin.

Improving fourth harmonic generation performance by elevating the operation temperature of ADP crystal.

In current inertial confinement fusion (ICF) facilities, potassium dihydrogen phosphate (KH2PO4, KDP) type crystals are the only nonlinear optical (NLO) materials that can satisfy the aperture requirement of the ICF laser driver. Ammonium dihydrogen phosphate (NH4H2PO4, ADP) crystal is a typical isomer of KDP crystal, with a large nonlinear optical coefficient, high ultraviolet transmittance, and large growth sizes, which is an important deep ultraviolet (UV) NLO material. In this paper, we investigated the effect of ADP temperature on its fourth-harmonic-generation (FHG) performance. When the temperature of the ADP crystal was elevated to 48.9 °C, the 90° phase-matched FHG of the 1064 nm laser was realized. Compared with the 79° phase-matched FHG at room temperature (23.0 °C), the output energy at 266 nm, conversion efficiency, angular acceptance, and laser-induced damage threshold (LIDT) increased 113%, 71%, 623%, 19.6%, respectively. It shows that elevating ADP temperature is an efficient method to improve its deep UV frequency conversion properties, which may also be available to other NLO crystals. This discovery provides a very valuable technology for the future development of UV, deep UV lasers in ICF facilities.

Introduction of LiCl into SnO2 electron transport layer for efficient planar perovskite solar cells

SnO2 has recently aroused huge attention as an electron transfer material for planar halide perovskite solar cells. Nevertheless, planar structure devices exhibit significant hysteresis behavior and low optical stability for their considerable trap states and high ultraviolet transmittance. In this study, LiCl was added to the SnO2 electron transport layer. As revealed from the results, adding LiCl could enhance the mobility of SnO2 film and promote the optical stability. Lastly, Li:SnO2 devices achieved high power conversion efficiency (PCE) of over 18% and steady-state PCE of 18.35%. Besides, they displayed prominent stability storage under dry conditions.

Lens transmittance shapes ultraviolet sensitivity in the eyes of frogs from diverse ecological and phylogenetic backgrounds.

The amount of short wavelength (ultraviolet (UV), violet and blue) light that reaches the retina depends on the transmittance properties of the ocular media, especially the lens, and varies greatly across species in all vertebrate groups studied previously. We measured the lens transmittance in 32 anuran amphibians with different habits, geographical distributions and phylogenetic positions and used them together with eye size and pupil shape to evaluate the relationship with diel activity pattern, elevation and latitude. We found an unusually high lens UV transmittance in the most basal species, and a cut-off range that extends into the visible spectrum for the rest of the sample, with lenses even absorbing violet light in some diurnal species. However, other diurnal frogs had lenses that transmit UV light like the nocturnal species. This unclear pattern in the segregation of ocular media transmittance and diel activity is shared with other vertebrates and is consistent with the absence of significant correlations in our statistical analyses. Although we did not detect a significant phylogenetic effect, closely related species tend to have similar transmittances, irrespective of whether they share the same diel pattern or not, suggesting that anuran ocular media transmittance properties might be related to phylogeny.

A novel type of borosilicate glass with excellent chemical stability and high ultraviolet transmission

The aim of the present work was to study a novel type of borosilicate glass with excellent chemical stability and high ultraviolet transmission. The impact of the content of Al2O3 and B2O3 on the microstructure and ultraviolet transmission of borosilicate glass was studied by Raman, FTIR, SEM and UV–VIS-NIR spectrophotometer. The chemical stability was studied by chemical stability test. The results showed that when the addition of Al2O3 increased, the chemical stability of the glass turned worse. We found that when the addition of B2O3 was 13 wt.%, the erosion degrees of the boron-rich phase of the glass was significantly more serious than other samples. And when the addition of B2O3 was 11 wt.%, it had the best chemical stability. Moreover, the UV transmittance of glass samples gradually decreased with increasing Al2O3 content, and the UV transmittance of glass samples increased first and then decreased with increasing B2O3 content.

Research on Dispersive Detection Technology Based on Digital Micromirror Device by Atomic Fluorescence Spectrometry

Abstract A ultraviolet (UV) digital micromirror spectrometer using a digital micromirror device (DMD) as a spatial light modulator, a grating as a spectroscope and a photomultiplier tube (PMT) as a detector, was specially designed for dispersive hydride generation atomic fluorescence spectrometry (HG-AFS). To improve the detection ability of the UV digital micromirror spectrometer for weak fluorescence signals at 180–320 nm, a high UV transmittance DMD was used and the signal acquisition system was improved, and the control parameters of DMD and PMT negative high voltage were optimized. The feasibility of the spectrometer was demonstrated with standard sample analyzing of As, Sb, Bi, and Hg, the emission and atomic fluorescence spectra were obtained, and the scattering interference caused by the light source was discussed. The results showed that the UV digital micromirror spectrometer had a preliminary ability for the excitation fluorescence analysis by HG-AFS. In addition, due to no macroscopic moving parts, the UV digital micromirror spectrometer had simple construction and fast analysis speed (0.848 s per spectrum scan).

Low Temperature Fabrication of Transparent Conductive Electrode With High Ultraviolet Transmittance Down to Wavelength of 250 nm

Indium tin oxide (ITO) is a broadly deployed transparent conductive electrode (TCE) with various applications in solar energy harvesting and optoelectronics. However, the low transmittance of ITO in the ultraviolet range has motivated researchers to opt for alternative materials as TCE. In this paper, the fabrication of a hybrid TCE made up of silver nanowire (AgNW) and peroxo‐constructed amorphous strontium stannate (pcaSS) is reported, employing facile spin coating solution‐processed method at 150 °C. The fabricated TCE demonstrated low sheet resistance of 32.8 Ω sq−1 and high transmittance of 88.2% at 550 nm. Furthermore, benefitting from the ultra‐high band gap of as‐synthesized pcaSS (4.5 eV), this TCE maintained its high transmittance (above 80%) inside ultraviolet range down to wavelength of 250 nm. This research contributes to the fabrication of more efficient solar energy and ultraviolet optoelectronic devices.

Large-Area Polymeric Microplasma Devices With Elongated Lifetime for Flexible Display and Photonic Applications

This letter describes the fabrication and performance of microplasma devices and arrays by a replica molding process in which the substrate is a flexible and ultraviolet (UV) transparent glass/polymer hybrid structure. In particular, ultrathin flexible glass sheets were embedded into the device so as to minimize outgassing of undesirable gas species and reinforce flexible substrates from the fatigue. Extended lifetime of the polymeric devices has been observed up to 200 h, with full recovery after refilling with gas. The major component of the devices has a high UV transmittance, and is transparent up to about 220 nm.

Combined effect of light harvesting strings, anti-reflective coating, thin glass, and high ultraviolet transmission encapsulant to reduce optical losses in solar modules

Optical losses are a major source for current and power reduction in solar modules. Hence, various improvements aiming at reducing these losses have been suggested. In this work, we have evaluated the effects of anti-reflective coating, front glass thickness, polyvinyl butyral ultraviolet+ encapsulant, and light harvesting strings on the module performance individually and in combination. The individual and combined contributions were quantified by spectrally resolved optical measurements on the module components and simulations as well as electrical measurements on 1-cell and 54-cell modules. Optical gains and their impact on short circuit current are discussed in relation to a maximum current obtained from the solar cells internal quantum efficiency. The results of the electrical characterization are in good agreement with the optical analysis substantiating our approach. They show that a combined, relative current enhancement of 5% can be obtained for an optimized module, which compares to an increase of 1% absolute efficiency. Copyright © 2014 John Wiley & Sons, Ltd.

Transmittance Properties of Contact Lens Multipurpose Solutions and Their Effects on a Hydrogel Lens

Purpose The aim was to assess the compatibility of different multipurpose solutions (MPSs) with one type of silicone hydrogel (SiH) contact lens by, assessing the changes in both ultraviolet (UV) and visible light transmissibility of the hydrogel lens caused by the MPSs. Methods The light transmittance from 200-700 nm were measured for the lotrafilcon B blister pack solution (BPS), six MPSs namely, ReNuMultiPlus Multi-Purpose Solution (Bausch and Lomb Inc., Rochester NY, USA.); Complete RevitaLens Multi-Purpose (Abbott Medical Optics Inc., Quarryvale Co. Dublin, Ireland); All In One Light (Sauflon Pharmaceuticals Ltd., Twickenham, England); SOLO-care AQUA™ (Ciba Vision Corporation Duluth, Georgia, USA.); Biomedics All-in-one solution (CooperVision, Hamble, UK); and HippiaMultiPlus All-in-one solution (Interojo Inc., Kyeonggi-do, Korea), and a lotrafilcon B SiH lens (before and after storage), using a spectrophotometer. Results The UV transmitted through the BPS and the MPS were similar (p >.05, for all), except for the HippiaMultiPlus which was lower (p < 0.001) by 19.8%. Mean transparency values were statistically (p<.001) significantly different between the BPS and the MPSs. All MP solution/SiH lens combinations resulted in relatively high UV transmittance values especially in the UVC spectrum, and significantly increased (p <.001) the visible light transmittance values of the SiH lens. Greater changes in transparency were observed in the ReNu/SiH lens (28.5%) and the Complete RevitaLens/SiH lens (24.9%) combinations. Conclusion The six MPSs showed significant variations in the transmitted UV and visible light. Similar to the BPS, all MPSs were equally transparent, but showed very poor UVA & UVB attenuation, except for the Hippia MultiPlus. The MPS/SiH lens combinations did not significantly affect the lens transparency but it significant increased the lens transmittance of UV radiation, after storage. Further in-vivo studies are needed to validate if this effect is constant.

Silver microgrid transparent conductive electrode based on bulk plasmon effect for ultraviolet wavelength application

AbstractSilver microgrid/TiO2/ITO (indium tin oxide glass) sandwich‐structure photodetectors with various pore sizes are fabricated by a microsphere lithography strategy. This ultraviolet (UV) detector possesses ohmic contact characteristics. The high UV transmittance results from an enhanced bulk plasmon effect of the silver microgrid electrode. Photoelectric properties of the sandwich structure with various pore sizes are discussed. The short transport distance of carriers and the low blocking of incoming UV light are the main reasons of the high activity for silver microgrid/TiO2/ITO sandwich‐structure photodetectors. (© 2013 WILEY‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

TiOx/Ag/TiOx multilayer for application as a transparent conductive electrode and heat mirror

Amorphous TiOx films and Ag layer were deposited by electron-beam evaporation on soda-lime glass at room temperature. The details regarding the structure, surface morphology, and optical properties of the as-prepared TiOx films were examined by X-ray diffraction, scanning electron microscopy, and ultra-violet (UV) -visible-near-infrared (NIR) spectrometry. The TiOx films exhibit amorphous phase with an optical band gap of 3.35 eV. The polygrains oriented along the (111) and (200) directions in the Ag films were adopted to supply carriers into the TiOx film and lower the sheet resistance of the stacked layer. The multilayer exhibited a sufficiently large Ag thickness (>15 nm), low resistance, high UV transmittance, visible transmittance, and high NIR reflection. Dependence of Ag thickness, TiOx bottom-layer, and TiOx overlayer on the optical and electrical properties of TiOx/Ag/TiOx were explored. A figure of merit (FOM) was used to find an optimal structure for a multilayer with superior conductivity and visible transparency. An FOM of 9.8 × 10−2 (Ω−1) at the visible wavelength of 550 nm for a TiOx/Ag/TiOx stacked layer with an 18-nm-thick Ag and a 20-nm-thick TiOx was achieved. The TiOx/Ag/TiOx sample annealed at 500 °C 10 min also shows a good thermal stability.

Enhanced light output power of near UV light emitting diodes with graphene / indium tin oxide nanodot nodes for transparent and current spreading electrode

We report GaN-based near ultraviolet (UV) light emitting diode (LED) that combines indium tin oxide (ITO) nanodot nodes with two-dimensional graphene film as a UV-transparent current spreading electrode (TCSE) to give rise to excellent UV emission efficiency. The light output power of 380 nm emitting UV-LEDs with graphene film on ITO nanodot nodes as TCSE was enhanced remarkably compared to conventional TCSE. The increase of the light output power is attributed to high UV transmittance of graphene, effective current spreading and injection, and texturing effect by ITO nanodots.

Investigation of Ultraviolet Transmission Characteristics of Detecting Window in Ultraviolet Corona Inspector

Ultraviolet (UV) corona inspector is used to detect corona according to the ultraviolet radiation of the discharge. High detecting sensitivity of the inspector requires high ultraviolet transmission property of the detecting window. In this paper, high performance JGS-1 (type name of glass) ultraviolet quartz glass is used as the inspector detecting window material and the ultraviolet transmission characteristics of the glass is studied. A new method with the smart corona detecting module to test the ultraviolet transmission parameter of quartz glass is demonstrated. The comparison results of UV spectrometer and this new method manifest that JGS-1 quartz glass has good ultraviolet transmission character and the new test method with corona detecting module is direct and feasible.

Comparative Optical Characteristics of Sheet Glasses

The paper provides a comparative analysis of the ability of sheet glass produced by different companies to transmit solar radiation in different ranges: 300 – 2500 nm (direct solar transmission), 300 – 380 nm (ultraviolet transmission), and 380 – 780 nm (light transmission). It is demonstrated that a high level of light transmission does not always ensure high ultraviolet transmission.

Laser-heated diamond anvil cell system for photochemical reaction measurements

A laser heating system constructed for photochemical reaction within a diamond anvil cell features a tunable pulsed laser and an excimer laser ranging from ultraviolet to infrared in a continuous-wave Nd:yttrium–aluminum–garnet laser heating system. Pulse duration is measured during experiments using a high-speed photoreceiver and pulse modes are measured by a beam profiler. High-purity synthetic diamond with high ultraviolet transmittance are used to avoid damaging the anvils. Decomposition of silver iodide by an excimer laser irradiation is confirmed under high pressure. This laser technology will, combined with high-pressure experiments, open up avenues in photochemical reaction processes.

Functional Significance and Induction by Solar Radiation of Ultraviolet-Absorbing Sunscreens in Field-Grown Soybean Crops

Colorless phenylpropanoid derivatives are known to protect plants from ultraviolet (UV) radiation, but their photoregulation and physiological roles under field conditions have not been investigated in detail. Here we describe a fast method to estimate the degree of UV penetration into photosynthetic tissue, which is based on chlorophyll fluorescence imaging. In Arabidopsis this technique clearly separated the UV-hypersensitive transparent testa (tt) tt5 and tt6 mutants from the wild type (WT) and tt3, tt4, and tt7 mutants. In field-grown soybean (Glycine max), we found significant differences in UV penetration among cultivars with different levels of leaf phenolics, and between plants grown under contrasting levels of solar UV-B. The reduction in UV penetration induced by ambient UV-B had direct implications for DNA integrity in the underlying leaf tissue; thus, the number of cyclobutane pyrimidine dimers caused by a short exposure to solar UV-B was much larger in leaves with high UV transmittance than in leaves pretreated with solar UV-B to increase the content phenylpropanoids. Most of the phenylpropanoid response to solar UV in field-grown soybeans was induced by the UV-B component (lambda </= 315 nm). Our results indicate that phenolic sunscreens in soybean are highly responsive to the wavelengths that are most affected by variations in ozone levels, and that they play an important role in UV protection in the field.

Initial Results With the Objective Prism of the Uk Schmidt Telescope

AbstractThe U. K. 1.2m Schmidt objective prism with its small apex angle (23’12”) and high ultraviolet transmission is a particularly powerful tool for the study of faint objects. It has been shown that objects of 20m and fainter can be reached on a 60 minute exposure of unwidened spectra on hypersensitized IIIa-J emulsion. A description of the prism and its performance has already been published (Nandy et al. 1977).

Efficient upconversion of long-wavelength uv light into the 200–235-nm band

Phase-matched nonlinear generation of the second harmonic of visible laser sources has been limited to wavelengths longer than about 230 nm because the dispersion of available materials with high ultraviolet transmission cannot be compensated by their birefringence. Parametric upconversion of uv in the range 250–325 nm to the 200–235-nm band by mixing with a strong infrared signal can be accomplished with 90° phase matching in 45° z-cut crystals of ADP. A particularly useful embodiment of this idea is the upconversion of dye laser second-harmonic wavelengths by mixing with the 1.064-μm output of the Nd:YAG laser. Preliminary experiments in upconverting 266-nm light to 213 nm have demonstrated stable conversion efficiencies above 50% for this process with peak and average powers above 5 kW and 0.5 mW, respectively.