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In photocatalytic innovation, there has been a lot of interest in creating broad spectral responsive photocatalysts to get superior catalytic performance. In this study, we synthesized highly visible‐light responsive La2Ti2O7 perovskite photocatalysts by the probe ultrasonication procedure followed by high‐temperature calcination. Such materials are characterized using UV‐vis diffuse reflectance spectra, powder X‐ray diffraction, X‐ray photoelectron spectroscopy, and scanning electron microscopy to illustrate the optical absorption activities, crystalline properties, chemical composition, and microscopic features. La2Ti2O7 extends optical absorption towards the visible light spectrum and narrows the band gap. The photocatalytic efficacy of the resulting La2Ti2O7 nanostructures was investigated by performing photocatalytic degradation of persistent Congo red (CR) dye while subjected to visible photon illumination using three Osram 150 W tungsten halogen lamp ((λ≥400 nm), 5000 lm nominal luminous flux, 80,600 lx radiation intensity. With effective efficiency, the optimum degradation of the 10 ppm CR dye with a percentage of 95.9 was achieved after 90 min during exposure to the La2Ti2O7 perovskite with a catalyst dosage of 30 mg/100 mL at pH 6. Consequently, La2Ti2O7 nanostructures alone depicted 19.8 % adsorption efficiency for CR dye. In addition, OH⋅ and holes were important in degrading CR dye, which included many different reaction pathways. The treated solution can also demonstrate the environment's safety for accepting water. In summary, under natural visible light irradiation, the synthesized La2Ti2O7 showed enormous promise for eliminating different organic contaminants using photocatalytic methodology. [ABSTRACT FROM AUTHOR]

In laser illumination, there is considerable interest in phosphor‐converted laser diodes that boast high efficiency and exceptional thermal stability. Phosphor‐in‐glass (PiG) and phosphor‐in‐glass film (PiF) are highly favored for their efficiency, cost‐effectiveness, and ease of fabrication. To tackle the issue of low thermal conductivity of glass, a novel lithium–aluminum–silicate glass is innovatively developed. This glass induces the precipitation of spodumene crystalline phase, enhancing material stability. Utilizing solid‐state sintering techniques, Y3Al3.5Ga1.5O12:Ce3+ (YAGG:Ce) PiG is fabricated, which exhibited a luminous flux (LF) of 866.76 lm under 450 nm blue light with 3.88 W input power. Benefiting from the high thermal conductivity of sapphire substrate and the high‐intensity glass system, YAGG:Ce PiF demonstrated a saturation threshold of 10.20 W, yielding an impressive LF of 2178.1 lm, which is 2.5 times that of PiG samples. Notably, the thermal conductivity increased significantly from 2.2 W m−1K−1 (PiG) to 7.0 W m−1K−1 (PiF), surpassing traditional organic resin materials. To validate the practicality of the two‐color converters, it integrates them into both starlight lamp and laser flashlight modules for encapsulation, thereby generating attractive green light in various environments. This design holds the potential to become the ideal choice for the next generation of high‐power, high‐brightness laser illumination. [ABSTRACT FROM AUTHOR]

Annual VIIRS global night-time lights traditionally report mean radiance levels after filtering to remove moonlit and cloudy data followed by outlier removal. The mean is the first statistical moment, but there are three other statistical moments (variance, skew and kurtosis) that are currently not produced globally. In this study, we generated VIIRS day/night band multiyear and annual statistical moments for a widely dispersed set of test areas. The moments were calculated from 15 arc second nightly temporal profiles spanning 2012–2020, filtered to exclude cloudy and sunlit data, with radiance adjustments to reduce view angle and lunar illuminance effects. The moment data were examined in two ways: (1) Geospatial grids-which reveal zonation and temporal changes present in urban areas and (2) Scattergrams of moment pairs. The variance versus mean scattergram exhibits several distinct data clusters used to define five zones: core lighting, dark-erratics, mid-erratics, bright-erratics and bright and seteady. The results indicate that the information content of VIIRS night-time lights can be augmented if all four statistical moments are calculated. [ABSTRACT FROM AUTHOR]

The underwater imaging environment is very different from land, and some common land image enhancement methods are often not applicable to the underwater environment. This paper proposes a two-step underwater image enhancement method. White balance is a commonly used color correction method. In underwater environments, the traditional white balance method has certain limitations and results in severe color bias. This is caused by the faster attenuation of red light in underwater environments. We develop a new white balance method based on the assumption of the gray world method. A red correction module is embedded in the method, which is more suitable for underwater environments. For contrast correction, we design an illuminance correction method based on the Retinex model. The method significantly reduces the computational burden compared to traditional methods, while enhancing the brightness and contrast of the images. In addition, most of the current underwater image enhancement methods deal with color and contrast issues separately. However, these two factors influence each other, and processing them separately may lead to suboptimal results. Therefore, we investigate the relationship between color and contrast and propose a trade-off method. Our method integrates color and contrast within a histogram framework, achieving a balanced enhancement of both aspects. To avoid chance, we utilized four datasets, each containing 800 randomly selected images for metric testing. On the five non-referential metrics, three firsts and two seconds were ranked. Our method ranked second on two referenced metrics. Superior results were also achieved in runtime comparisons. Finally, we further demonstrate the superiority of our method through detailed demonstrations and ablation experiments. [ABSTRACT FROM AUTHOR]

Orthopedic surgical robots utilize near-infrared (NIR) optical locators to enable precise navigation during operations. Markers are crucial in the locator system, capturing the positions and orientations of surgical instruments and patients during operation. While spherical markers can be easily detected, they are less robust owing to limited feature points. In contrast, planar markers offer more feature points and greater resistance to occlusion. However, the demanding nature of orthopedic surgeries necessitates specific requirements for NIR-based planar markers, such as size, illumination, weight, and heat dissipation. To address these challenges, we designed an edge-lit NIR calibration board (300 mm × 300 mm) to calibrate the constructed NIR camera, with its effectiveness validated through extensive experimental studies. Based on the fundamental design data obtained from the designed edge-lit NIR calibration board, and considering the luminous flux density and the available 12 V battery on the market, we proposed an edge-lit active NIR planar marker with dimensions of 70 mm × 60 mm and equipped with eight LEDs (1.5 V, 0.085 W each). The experiential data illustrates the max relative standard deviation are around 0.93% and 0.78% for the measurement precision subjected to 10 mm × 10 mm square (5 × 5 squares) with 16 and 36 feature points, respectively. Further, we validated the following from the experimental results: (1) A 12 V 1000 mAh alkaline battery has an autonomy of approximately 16 h for the eight NIR LEDs. (2) The total heat energy conversion of 0.408 W for the marker is within acceptable limits for use in an operation room. (3) The total weight of approximately 21.6 g, including the planar marker and the selected battery, is manageable. Therefore, the designed edge-lit active NIR planar marker presents a viable option for integration into the locator system of orthopedic surgical robots. [ABSTRACT FROM AUTHOR]

The near-field - far-field disparity of light sources leads to discussion within the lighting community. In the far-field, light sources are approximated by a point source with a luminous intensity distribution from which other photometric quantities can be computed. In the near-field, light sources must be considered as extended sources and no closed-loop analytical solutions can be found for the illuminance in off-axis directions. The illuminance allows to compute the apparent intensity used for the assessment of the limiting photometric distance (LPD), that is, the threshold between near- and far-field regions. Numerically, the illuminance can be determined through a discretisation of the luminous surface. This approach is verified for on- and off-axis directions through direct comparison with ray tracing simulations based on near-field goniophotometric measurements. A good match is observed for Lambertian and narrow beam light sources. Using the numerical approach, the LPD in all directions is assessed. For light sources of which the luminous intensity strictly decreases while moving away from the optical axis, the LPD decreases as well until a minimal value is reached. After this, the LPD increases again, in certain scenarios up to values resulting in the invalidity of the inverse square law. [ABSTRACT FROM AUTHOR]

Museum conservation guidelines restrict illuminance for sensitive artwork to levels that can cause objects to be perceived as less colourful, a phenomenon known as the Hunt effect. Previous colour rendering research identified red saturating gamuts that consistently increased perceived saturation and personal preference. A study was conducted to evaluate the visual experience of fine art illuminated by a red saturating gamut family constrained to be uniquely identified by their TM-30 gamut scores (denoted as R g * ) and position above or below the blackbody locus (D uv). R g * and D uv were systematically varied according to response surface methodology, designed to map second-order terms and interactions, with 96 ⩽ R g * ⩽ 124 and −0.0212 ⩽ D uv ⩽ 0.0036, all at 3000 K and 50 lx. Thirty-one naïve participants each evaluated a pair of paintings in a mock art gallery under nine independently presented scenes along semantic scales corresponding to preference, saturation and naturalness. The study identified a response surface for preference that maps an interaction between R g * and D uv, predicting D uv = −0.013 was preferred at R g * = 100 and D uv = −0.005 was preferred at R g * = 120. Increasing R g * consistently increased both personal preference and perceived saturation. [ABSTRACT FROM AUTHOR]

To reveal the effects of illuminance and spectral band changes on coal and gangue image and spectral parameters, and to provide fundamental data for using multispectral images in coal and gangue recognition research, this paper analyzes image parameters (standard deviation, skewness, entropy, and contrast) and the spectral parameter using experimental methods, and compares the differences between coal and gangue parameter values. First, we analyze the variations of parameters, and find that as illuminance increases, the image parameters fluctuate in shorter spectral bands but change slightly in longer ones, while the spectral parameter increases across all bands; as wavelength increases, the image parameters rise or fluctuate within 546–622 nm, while the spectral parameter increases; in other bands, all parameters initially decrease before stabilizing. Second, we compare parameter deviation by normalizing coal and gangue values, and find that coal and gangue have the largest deviation in the spectral parameter, and the smallest in skewness; they have the largest fluctuation range in entropy, and the smallest in skewness; image parameters are more sensitive to changes in illuminance and spectral bands than the spectral parameter; and the deviations in both image and spectral parameters are larger at 7000lux and 585 nm than at other settings. [ABSTRACT FROM AUTHOR]

Color shift keying is a modulation scheme for visible light communication that uses fixtures with three or more narrow-spectral light-emitting diodes to transmit data while fulfilling the primary function of illumination. When this modulation is used indoors, the reflectivity of the walls strongly affects the inter-channel interference and illumination quality. In this paper we present an indoor channel model that takes into account multi-wavelength propagation. This model is available as an open-source Python package. The model calculates the inter-channel interference, illuminance, correlated color temperature, and color rendering index at the receiver position. The Python package includes a module for estimating the symbol error rate. To validate the model, we computed the received power at each color photodetector for four different indoor scenarios. The model demonstrated a color rendering index of less than 15 when using IEEE-based color shift keying and non-uniform illumination on a horizontal plane. The simulation determined the required luminous flux to achieve a symbol error rate of less than 10 − 5 when the photodetector is at the center of the indoor space and vertically below the light source. To maintain a symbol error rate less than 10 − 5 , the luminous flux increases when the photodetector is displaced in a diagonal direction from the center of the plane. [ABSTRACT FROM AUTHOR]

Daylight is one of the essential criteria for decent housing. However, in an urban kampung, access to daylight is limited due to the high-density population in urban Kampung Kota. This study aims to improve the visual and thermal conditions by modifying the aperture of the light pipe based on visual daylight distribution, illuminance level, and thermal conditions in multi-storey houses in hot-humid climates. Light pipe was developed experimentally through the simulation model to investigate the performance and impact on the visual and thermal conditions like operational temperature and RH in densely populated Kampung Kota without vertical apertures. According to the results, the two-aperture light pipe residential space enhanced the current situation but did not fulfill the standards. The two aperture light pipe visually improved daylight distribution by 1.05% -31.36% and illumination level by 8.4% - 14.8%. We also found that light pipe also impacts thermal conditions with a 10.92% RH reduction while at the same time increasing temperature up to 10.57%. Therefore, it can be concluded that a two-aperture light pipe has the potential to be applied to actual conditions in hot-humid climates. [ABSTRACT FROM AUTHOR]

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Daylight influences more than just our vision; elements such as its intensity and spectral composition can significantly impact our circadian rhythms and, consequently, our overall well-being. In this study, we present an analysis of a classroom simulated in Dialux, involving a comprehensive examination of natural daylight through a specific type of glazing, assessing their photopic characteristics and their influence on the human circadian system in individuals aged 32 and 70 years. Our findings highlight that spectral data from daylight (D75, D65, and D50) and glazing transmittance can be easily used to evaluate the melanopic equivalent daylight illuminance (mel-EDI) in addition to standard photopic illuminance, applying a f ( M P ) G l a z i n g factor calculated from the spectral characteristics of both daylight and glazing transmittance. Our results provide new insights for users to more effectively assess daylighting quality and its implications within indoor environments. [ABSTRACT FROM AUTHOR]

Daylight plays a crucial role in human health, and as research into its effects expands, it is essential for designers to estimate the non-image-forming impacts of various daylighting and lighting strategies. This allows them to create indoor environments that are both pleasant and comfortable. To support this, daylight measurements were taken in five Chinese cities, focusing on spectral power distribution, correlated color temperature, and illuminance. The study calculated the non-image-forming effects of daylight exposure using metrics like melanopic Equivalent Daylight Illuminance and Circadian Light. A key finding was the development of the action factor SAI, which estimates the potential non-image-forming effects of light in built environments. This factor serves as a proxy for understanding how non-image-forming effects relate to correlated color temperatures. Additionally, the research suggests the possibility of creating a time-variational daylighting and lighting strategy with four distinct periods of non-image-forming effects throughout a 24 h day. These insights could be valuable for architects and designers in optimizing indoor lighting systems. [ABSTRACT FROM AUTHOR]

Laser-driven white lighting is believed to be a future-oriented high-brightness solid-state light (SSL) source, which is confronted with a severe challenge in developing a laser-driven color converter with efficient thermal management. Herein, a unique architecture of phosphor-in-glass film bonded with a microchannel cooling (PiGF-MC) converter was proposed to enable high luminescence saturation for high-brightness laser-driven white lighting. The PiGF consisted of yellow-emitting Y 3 Al 5 O 12 :Ce3+ (YAG) was sintered on an alumina substrate and then soldered on a liquid-cooled microchannel radiator, which realizes outstanding heat dissipation performance of laser-driven PiGF. The PiGF-MC converter possesses luminance saturation threshold under a high laser power density of 21 W mm−2, 2.3 times that of the traditional PiGF-alumina converter (∼9 W mm−2). High-brightness laser-driven white light is achieved by the PiGF-MC with a high luminous flux of 2953 lm@21 W mm−2, and long-term stable optical performance is simultaneously realized. The working temperatures of laser-driven PiGF-MC are all lower than 200 °C under various laser powers. This finding demonstrates the broad prospect of the proposed PiGF-MC converter architecture for next-generation high-brightness laser-driven white lighting. [ABSTRACT FROM AUTHOR]

The presented article addresses the issue of the maintenance factor, which forms a part of the design variables in artificial lighting within engineering practices from a sustainability perspective. The maintenance factor was monitored using two simulation tools—Dialux, version 5.12.0.5527 and Relux, version 2024.2.8.0. In a production hall, inadequate lighting was identified with a value below 300 lx, prompting a redesign of the lighting system. The overall methodology of the Ergonomic Rationalization Sequence was expanded in the "Design of Lighting System" phase to include the determination of the maintenance factor as a necessary parameter for sustainability, which was subsequently verified in a virtual environment using two options in a practical study. According to the in situ measurements, the virtual environments of the production hall were created for both software, in which four alternatives for the lighting system were developed. The illuminance values met the normative requirements in each alternative; however, the first two (illuminance values 1000 lx–1200 lx) were predicted to have long-term high-energy consumption. In alternatives 3 and 4, the number of luminaires was therefore reduced from 6 pieces to 4, with a total illuminance in the range of 680 lx–780 lx. The determination of the variations in the methods for establishing the maintenance factor identified a deviation of 5%, which, indicating the changes in illuminance values, can be considered as the occurrence of a gross error in lighting design. [ABSTRACT FROM AUTHOR]

Phosphors-in-glass films (PiGFs) with thermally conductive substrates are considered to be an efficient color inorganic color conversion material for laser lighting. However, due to the contradiction between the light extraction and heat dissipation, achieving high brightness and excellent color quality simultaneously is still a big challenge. Herein, a unique architecture of bicolor PiGF with highly reflective interface design was proposed for high-quality laser lighting. The TiO 2 -glass films with different thicknesses were prepared on highly heat-conducting AlN substrates to obtain the TiO 2 –AlN (TA) substrates with various reflectance. In addition, mixed green/red, stacked green-red, and stacked red-green phosphor glass films were printed and sintered on the TA substrates to prepared three bicolor PiGF converters of M-PiTA, G-R-PiTA, and R-G-PiTA. At the TiO 2 -glass film thickness of 100 μm, the M-PiTA enables a luminous flux of 2053 lm@24.8 W/mm2, which is 1.9 times that of traditional M-PiGF-AlN converter (1077 lm@17.6 W/mm2). The M-PiTA converter realizes a high-quality white light with a CRI of 82.7 and a chromaticity coordinate of (0.3378, 0.3297). Furthermore, the M-PiTA converter enables higher luminance and light quality compared with the stacked G-R-PiTA and R-G-PiTA converters. With the laser power of 4.2 W, the working temperature of M-PiTA converter is only 59.2 °C, while that of R-G-PiTA and G-R-PiTA converters rises to 499 °C and 301 °C. The results demonstrate that the bicolor PiTA converters have broad prospects in the application of laser lighting. [ABSTRACT FROM AUTHOR]

Next‐generation high‐brightness lighting faces a big challenge in developing laser‐drivable color‐converting materials with effective thermal management. Herein, a new material architecture of Al2O3‐Y3Al5O12: Ce3+ (YAG: Ce) transparent composite ceramics coated with Al film (TCC@Al) is proposed. The as‐prepared material shows the highest thermal conductivity (29.3 W m−1 K−1) among YAG: Ce‐related transparent ceramics (TC) ever reported owing to the combination role of short‐range thermal conduction of Al2O3 microcrystals and long‐range thermal conduction of Al film. Temperature‐dependent photoluminescence (PL) spectra and femtosecond transient absorption (fs‐TA) spectra evidence the importance of thermal management, whereby the luminescent loss of TCC@Al is only 8.92% at 450 K and is far smaller than TC counterpart (15.86%). Importantly, no obvious luminescence saturation is detected upon 20 W mm−2 blue laser irradiation and the inhomogeneous angular color distribution is suppressed by the scatter of Al2O3 microcrystals, yielding uniform white light with ultra‐high luminous flux (LF) of 4294 lm@20 W mm−2 and luminous efficacy (LE) of 215 lm W−1. As a consequence, the present TCC@Al‐converted laser‐driven lighting prototype exhibits much better optical performance than the commercial TC‐based one. [ABSTRACT FROM AUTHOR]

Purpose: Defocus Incorporated Soft Contact (DISC) lenses, a commonly used type of multifocal lens in clinical practice, may slow down myopia progression by inducing myopic retinal defocus. The purpose of this study was to explore whether the induced defocus across the retina could be affected by visual environments encountered in the real world, such as differences in viewing distance and ambient illuminance. Methods: In this cross‐over trial, 30 myopic adults wore both DISC lenses and single vision contact (SVC) lenses in random order. An open‐view Hartmann–Shack scanning wavefront sensor was used to measure defocus at different retinal locations along the horizontal meridian under four experimental conditions: far target (3 m) and near targets (0.33 m) under scotopic (<1 lux) or photopic (~300 lux) conditions. Results: The results showed that DISC lenses induced more myopic retinal defocus than SVC lenses in all conditions (all p < 0.05), except for the scotopic near target. In addition, for DISC lenses, the defocus was greater in the photopic than the scotopic conditions for both the far and near targets (both p < 0.05). Conclusion: In conclusion, the retinal defocus induced by these multifocal lenses was dependent on both visual distance and ambient illuminance, indicating that the visual conditions might affect the anti‐myopia efficacy of these devices. [ABSTRACT FROM AUTHOR]

This paper presents a UAV-based road illumination measurement system and evaluates its performance through experiments. The system employs a HUBSAN Zino 2+ UAV, STM32F103RCT6 microcontroller, BH1750 illuminance sensor, and GPS and integrates flight, processing, measurement, cloud platform, obstacle avoidance, communication, and power supply units via the OneNET cloud platform. Both hardware and software designs were implemented, using the Z-score algorithm to handle outliers in illumination data. The system showed a single-point measurement error rate of 1.14% and a MAPE of 5.08% for multi-point measurements. In experiments, the system's horizontal and vertical illuminance RMSE were 1.92 lx and 1.75 lx, respectively. The real-time visualization interface improved operational efficiency, cutting labor costs by half and time costs by nearly four-fifths. UAV control and monitoring from the roadside ensured safety during measurements. The system's efficiency and wide measurement range enabled extended experiments, collecting illuminance data across multiple horizontal and vertical planes. This resulted in the creation of both horizontal and innovative vertical-plane illuminance distribution maps. These findings provide valuable data for evaluating road lighting quality, enhancing road traffic safety, and improving road illumination design. [ABSTRACT FROM AUTHOR]

A semi-permanent two-dimensional (2D) code with ultra-small holes that can be embedded in various building materials and read with smartphones was developed. The code, called Porous code, is made of high-frequency cells of "1" data composed of shadows created from ultra-small holes corresponding to black cells in a Quick Response (QR) code and low-frequency cells of "0" data without holes, and thus no shadows, corresponding to white cells in a QR code. To read the code, it is first processed as follows: conversion to grayscale, detection of edges, binarization, morphological dilation and erosion, and smoothing of brightness. Since a conventional 2D code is obtained, it can be decoded using a conventional 2D code reader. We clarified the structure of "1" cells to achieve high reading accuracy through reading experiments involving Porous codes embedded in wooden and metal plates with various numbers of holes per "1" cell and hole depths. We succeeded in reading Porous codes under an illuminance of 12.5 7600 lux and verified that it is robust against illumination changes. In particular, Porous codes with four ultra-small holes in "1" cells were stably read the fastest under various illuminances. We also succeeded in reading Porous codes embedded in cement paste and marble under illuminances of 100 and 6090 lux. Keywords: Porous code, IoT, 2D code, QR code, building material [ABSTRACT FROM AUTHOR]

4-probe measurements of surface resistivity, measurements of dark and light current-voltage characteristics, the possibilities of using a thin PdSi film to obtain perfect nano-sized ohmic contacts on the Si(111) surface have been investigated using Auger electron spectroscopy methods in combination with ion etching of the surface. It has been shown that the depth of Ni diffusion in the Ni-Si (111) system is 400 ‑ 500 Å at indoor temperature, and 70 – 80 Å in the Ni-PdSi-Si (111) system. The quality of the ohmic contact in the latter case does not change up to T = 800 K and withstands luminous flux illumination up to F = 1100 lux. It is shown that the resistivity of the PdSi film passes through a minimum at T = 900 – 1000 K. An analysis of the results obtained will be given in the article.

Double low-E glasses are effective and well-established choices for residential buildings in temperate climatic regions of Sydney, Australia, and Tehran, Iran. The current study’s measurements and field experiments have shown that using a double low-E windowpane can improve window total transmitted radiation energy (TSRE) and daylight glare factor. Nevertheless, spatial daylight autonomy (sDA) and daylight illuminance are the shortcomings of using double-low-E glasses. These implications demonstrated that using double low-E glazing is a double-edged sword. Despite its efficiency in improving energy consumption, it cannot satisfy daylight comfort requirements. Therefore, this research intends to find the most suitable solution to exploit double-low-E glasses’ benefits and avoid their drawbacks. Subsequently, the genetic algorithm has been used to find the optimum window size through a multi-objective simulation by Climate Studio. The findings suggest that the optimum WWR of 10.35%–10.99% in Tehran brings the daylight comfort metrics above the threshold while the energy consumption metrics are kept at a minimum. Similarly, for Sydney, these measures are 20%–24% room length for the horizontal dimension of a window and 33%–40% room height for the vertical penetration dimension. In this way, using a double low-E window pane is justifiable for both examined regions. [ABSTRACT FROM AUTHOR]

Thermally robust and highly stable bulk luminescent materials are essential for advancing high‐power laser‐driven lighting. In this study, we report a yellow–green LuAG:Ce–Al2O3 eutectic, synthesized using the laser‐heated pedestal growth (LHPG) technique. The emission intensity of the eutectics reaches a maximum at an Al2O3 content of 20% due to the enhanced light scattering. Additionally, owing to the high thermal conductivity of Al2O3, the prepared LuAG:Ce–Al2O3 eutectic exhibits low thermal quenching, with only a 5% loss in luminescence observed at 150°C, along with a high luminance saturation threshold of approximately 15.8 W·mm−2. When irradiated under blue laser excitation at 7.9 W, the prepared LuAG:Ce–Al2O3 eutectic demonstrates a luminous flux of 1917 lm and a luminous efficacy of 242.4 lm·W−1. These results highlight that the potential of LuAG:Ce–Al2O3 eutectics as luminescent materials for high‐power laser‐driven lighting applications. [ABSTRACT FROM AUTHOR]

A high‐power white laser source is prepared by using a 455 nm blue laser to excite YAG:Ce ceramics. To achieve high‐power output, a water‐cooling device is used to reduce the operating temperature of ceramics. The luminescence properties of laser‐excited phosphor ceramics are studied under different blue excitation power and different irradiation time. The experimental results show that the luminous flux of phosphor ceramics excited by the blue laser increases linearly with the increase of blue laser power, depending on the heat dissipation of the water‐cooling device. When the blue laser power increases to 73.1 W, the phosphor ceramics do not reach the luminescence saturation state. The luminous flux of phosphor ceramics excited by 73.1 W blue laser is stable within 60 min. The maximum luminous flux is 8094 lm, and the maximum working temperature of the ceramics is 110 °C. The experimental results show that water‐cooling packages are an effective means to realize high‐power white laser sources. [ABSTRACT FROM AUTHOR]

Current international optical science research focuses on the non-visual effects of lighting on human cognition, mood, and biological rhythms to enhance overall well-being. Nocturnal roadway lighting, in particular, has a substantial impact on drivers' physiological and psychological states, influencing behavior and safety. This study investigates the non-visual effects of correlated color temperature (CCT: 3000K vs. 4000K vs. 5000K) and illuminance levels (20 lx vs. 30 lx) of urban motor vehicle road lighting on driver alertness during various driving tasks. Conducted between 19:00 and 20:30, the experiments utilized a human-vehicle-light simulation platform. EEG (β waves), reaction time, and subjective evaluations using the Karolinska Sleepiness Scale (KSS) were measured. The results indicated that the interaction between CCT and illuminance, as well as between CCT and task type, significantly influenced driver alertness. However, no significant effect of CCT and illuminance on reaction time was observed. The findings suggest that higher illuminance (30 lx) combined with medium CCT (4000K) effectively reduces reaction time. This investigation enriches related research, provides valuable reference for future studies, and enhances understanding of the mechanisms of lighting's influence on driver alertness. Moreover, the findings have significant implications for optimizing the design of urban road lighting. [ABSTRACT FROM AUTHOR]

An asymmetric road lighting concept known as Probeam is investigated in this study for energy efficiency, contrast and visibility of vertical objects and road markings in highway lighting. Calculations based on road lighting standards, road surface and markings reflection characteristics and typical Dutch highway geometry, reveal that Probeam lighting improves the average visibility of objects and road markings over symmetrical lighting, however, with a 14% increase in luminous flux as per current road lighting standards. This increase in luminous flux is attributed to the symmetrical lighting's advantage in specular road surface reflection, leading to a reduction in the Counterbeam lobe size in the light intensity distribution when designed to meet the current road luminance requirement. Notably, by designing the Probeam luminaire to match symmetrical lighting's average visibility of vertical objects, for removing the road luminance requirement and dimming the luminaire, energy consumption is reduced by 52%. Halving the Probeam luminaire's mounting height leads to an impressive 82% energy savings. The study highlights the possibility of a balance in energy use and road safety using the Probeam concept, considering advancements in road luminaires and retroreflective materials. Due to glare, the relevance of the proposed Probeam concept is restricted to one-directional traffic on highways. [ABSTRACT FROM AUTHOR]

Objective: The purpose of the present study was to assess the influence of color temperature and illuminance of ambient light on the accuracy of different intraoral scanners (IOSs) in complete‐arch implant scans. Methods: An edentulous model with six implants and scan bodies was digitized by using a laboratory scanner (DW‐7‐140; Dental Wings) to obtain a reference mesh. Fifteen scans were performed employing two intraoral scanners (Trios 4;3Shape A/S and i700; Medit Co) at two illuminances (500 and 1000 lux) and three color temperatures (3200, 4400, and 5600 K). Scanning accuracy was measured by using a 3D metrology software program (Geomagic Control X). Kruskal–Wallis, one‐way ANOVA, and pairwise comparison tests were used to analyze the data (α =.05). Results: Significant differences in trueness and precision values were found among the different IOSs under the same ambient lighting condition and among the different lighting conditions for a given IOS (p <.05) except for trueness in i700 groups (p >.05). Conclusions: The influence on the accuracy of color temperature and illuminance varied depending on the intraoral scanner. An optimal ambient scanning light condition was not found; this should be adjusted based on the specific IOS system used. 3200 K of ambient light influences the precision of i700 when performed at 1000 lux, decreasing the accuracy. The variation of color temperature at the same illuminance does not affect the scanning accuracy of TRIOS 4, which obtained better accuracy in all scans at 1000 lux. [ABSTRACT FROM AUTHOR]

Simple Summary: Concerns about animal welfare practices have increased as consumer awareness and regulatory standards have evolved. This study investigated the effects of lairage conditions on welfare and meat quality of pigs during lairage periods. A total of 3070 finishing pigs were assigned to one of six groups arranged in two trials in a 2 × 3 factorial design according to the illuminance (under 40 lux (LX), over 40 lux (HX)) and stocking density (low density (LD), higher than 0.83 m2/100 kg; normal density (ND), 0.50–0.83 m2/100 kg; high density (HD), lower than 0.50 m2/100 kg) with high temperature (HT), higher than 24 °C; low temperature (LT), lower than 10 °C. Based on the obtained results, stocking of too-high (lower than 0.50 m2/100 kg) density at HT and stocking of too-low (higher than 0.83 m2/100 kg) density at LT are generally not good for meat quality and animal welfare. This study investigated the effects of lairage conditions on the welfare and meat quality of pigs during lairage periods. A total of 3070 finishing pigs were assigned to one of six groups arranged in two trials in a 2 × 3 factorial design according to the illuminance (under 40 lux (LX), over 40 lux (HX)) and stocking density (low density (LD), higher than 0.83 m2/100 kg; normal density (ND), 0.50–0.83 m2/100 kg; high density (HD), lower than 0.50 m2/100 kg) with high temperature (HT), higher than 24 °C; low temperature (LT), lower than 10 °C. Pigs stocked with HD showed lower aggression behavior and overlap behavior than those stocked with LD at LT. Pigs stocked with HD showed higher standing, sitting, and aggression behavior than those stocked with LD at HT. Pigs stocked with HD showed higher pH than those stocked with LD at LT. At HT, pigs stocked with LD showed higher pH, WHC, DL, and CL than those stocked with HD. At LT, pigs stocked with LD showed higher cortisol levels than those stocked with HD. However, pigs stocked with LD showed lower cortisol levels than those stocked with HD at HT. Based on the obtained results, stocking of too-high (lower than 0.50 m2/100 kg) density at HT and stocking of too-low (higher than 0.83 m2/100 kg) density at LT are generally not good for meat quality and animal welfare. [ABSTRACT FROM AUTHOR]

Summary: Light can influence many psychophysiological functions beyond vision, including alertness, circadian rhythm, and sleep, namely the non‐image forming (NIF) effects of light. Melanopic equivalent daylight illuminance (mel‐EDI) is currently recommended as the predictor of the NIF effects of light. Although light dose is also critical for entraining and regulating circadian cycle, it is still unknown whether relatively low mel‐EDI light exposure for prolonged duration in the evening would affect pre‐sleep arousal and subsequent sleep. In all, 18 healthy college students (10 females, mean [standard deviation] age 21.67 [2.03] years) underwent 2 experimental nights with a 1 week interval in a simulated bedroom environment. During experimental nights, participants were either exposed to high or low mel‐EDI light (73 versus 38 lx mel‐EDI, 90 versus 87 photopic lx at eye level, 150 photopic lx at table level) for 3.5 h before regular bedtime, and their sleep was monitored by polysomnography. Subjective sleepiness, mood, and resting‐state electroencephalography during light exposure were also investigated. Results showed no significant differences in sleep structure and sleep quality between the two light conditions, whereas 3.5 h of exposure to high versus low mel‐EDI light induced marginally higher physiological arousal in terms of a lower delta but higher beta power density before sleep, as well as a lower delta power density during sleep. Moreover, participants felt happier before sleep under exposure to high versus low mel‐EDI light. These findings together with the current literature suggest that evening prolonged relatively low mel‐EDI light exposure may mildly increase arousal before and during sleep but affected sleep structure less. [ABSTRACT FROM AUTHOR]

Summary: Light has many non‐image‐forming functions including modulation of pupil size and stimulation of alertness and cognition. Part of these non‐image‐forming effects may be mediated by the brainstem locus coeruleus. The processing of sensory inputs can be associated with a transient pupil dilation that is likely driven in part by the phasic activity of the locus coeruleus. In the present study, we aimed to characterise the task‐evoked pupil response associated with auditory inputs under different light levels and across two cognitive tasks. We continuously monitored the pupil of 20 young healthy participants (mean [SD] 24.05 [4.0] years; 14 women) whilst they completed an attentional and an emotional auditory task whilst exposed to repeated 30–40‐s blocks of light interleaved with darkness periods. Blocks could either consist of monochromatic orange light (0.16 melanopic equivalent daylight illuminance (EDI) lux) or blue‐enriched white light of three different levels [37, 92, 190 melanopic EDI lux; 6500 K]. For the analysis, 15 and then 14 participants were included in the attentional and emotional tasks, respectively. Generalised linear mixed models showed a significant main effect of light level on the task‐evoked pupil responses triggered by the attentional and emotional tasks (p ≤ 0.0001). The impact of light was different for the target versus non‐target stimulus of the attentional task but was not different for the emotional and neutral stimulus of the emotional task. There is a smaller sustained pupil size during brighter light blocks but, a higher light level triggers a stronger task‐evoked pupil response to auditory stimulation, presumably through the recruitment of the locus coeruleus. [ABSTRACT FROM AUTHOR]

Summary: Light triggers numerous non‐image‐forming, or non‐visual, biological effects. The brain correlates of these non‐image‐forming effects have been investigated, notably using magnetic resonance imaging and short light exposures varying in irradiance and spectral quality. However, it is not clear whether non‐image‐forming responses estimation may be biased by having light in sequential blocks, for example, through a potential carryover effect of one light onto the next. We reasoned that pupil light reflex was an easy readout of one of the non‐image‐forming effects of light that could be used to address this issue. We characterised the sustained pupil light reflex in 13–16 healthy young individuals under short light exposures during three distinct cognitive processes (executive, emotional and attentional). Light conditions pseudo‐randomly alternated between monochromatic orange light (0.16 melanopic equivalent daylight illuminance lux) and polychromatic blue‐enriched white light of three different levels (37, 92, 190 melanopic equivalent daylight illuminance lux). As expected, higher melanopic irradiance was associated with larger sustained pupil light reflex in each cognitive domain. This result was stable over the light sequence under higher melanopic irradiance levels compared with lower ones. Exploratory frequency‐domain analyses further revealed that sustained pupil light reflex was more variable under lower melanopic irradiance levels. Importantly, sustained pupil light reflex varied across tasks independently of the light condition, pointing to a potential impact of light history and/or cognitive context on sustained pupil light reflex. Together, our results emphasise that the distinct contribution and adaptation of the different retinal photoreceptors influence the non‐image‐forming effects of light and therefore potentially their brain correlates. [ABSTRACT FROM AUTHOR]

This paper presents an indoor positioning strategy based on Visible Light Communication that relies on LED luminaires as transmitters, whose luminous flux is modulated at different frequencies, and a light sensor as a receiver. Then, a previously trained Artificial Neural Network (ANN) uses the illuminance signal gathered by the receiver as input to estimate the sensor's position. The main contribution of the technique is that the ANN is trained by using an illuminance estimator based on the lighting distribution of the luminaires, which is obtained through the IES file provided by the luminaire's manufacturer, without the need to collect data from the environment. In this work, the designed illuminance estimator is validated by comparing it to the well-known commercial software DIALux and Relux. The algorithm's setting and the performance evaluation of the ANN are explained. Then, the impact of the lighting uniformity and the environment's number of divisions on the accuracy of the results is analyzed. Error analyses are also made by adding uncertainty to the illuminance measurements obtained by the sensor. Finally, the work is compared to several papers in the field. [ABSTRACT FROM AUTHOR]

The growing demand for Location-based Augmented Reality (LAR) experiences has driven the integration of Visual Simultaneous Localization And Mapping (VSLAM) with Google Street View (GSV) to enhance the accuracy. However, the impact of the ambient light intensity on the accuracy and reliability is underexplored, posing significant challenges in outdoor LAR implementations. This paper investigates the impact of light conditions on the accuracy and reliability of the VSLAM/GSV integration approach in outdoor LAR implementations. This study fills a gap in the current literature and offers valuable insights into vision-based approach implementation under different light conditions. Extensive experiments were conducted at five Point of Interest (POI) locations under various light conditions with a total of 100 datasets. Descriptive statistic methods were employed to analyze the data and assess the performance variation. Additionally, the Analysis of Variance (ANOVA) analysis was utilized to assess the impact of different light conditions on the accuracy metric and horizontal tracking time, determining whether there are significant differences in performance across varying levels of light intensity. The experimental results revealed that a significant correlation (p < 0.05 ) exists between the ambient light intensity and the accuracy of the VSLAM/GSV integration approach. Through the confidence interval estimation, the minimum illuminance 434   lx is needed to provide a feasible and consistent accuracy. Variations in visual references, such as wet surfaces in the rainy season, also impact the horizontal tracking time and accuracy. [ABSTRACT FROM AUTHOR]

Light pollution in recent years has drawn surging public concerns in Hong Kong. The improper management of the light sources causes pollution, particularly light trespass on the community level, which obstructs the residents. Yet more studies are expected to quantitatively and systematically assess the severity of the artificial light trespass problem, and to offer practical solutions for mitigation and urban management. This study was conducted on a typical high-density, mixed-use neighbourhood in Tsim Sha Tsui district. The study consists of on-site measurement and model simulation. Three illuminance measurements were conducted to evaluate the impact of light pollution on the streets and light trespass on the nearby buildings. It was found that the impacts on the buildings (mean illuminance of 3 lx) are less significant than on the streets (mean illuminance of 188 lx) for the target study area. Indoor measurement at various height levels showed a mean illuminance level of 0.6 lx, which is much lower than the international limit of 25 lx. Meanwhile, the modelling work, consisting of correlation, verification and regression analysis, was carried to bridge luminous flux from light sources and illuminance received at the target. A three-dimensional (3D) model was developed to mimic the actual situation and was used to identify the primary light sources causing impacts. While a growing number of research is found on measuring and modelling the intricate light pollution in such a micro scale that elevates explicitly the importance of extrapolating the light pollution effect vertically from street level to building level, direct simulation is still lacking. This study also refined and summarised the research methodology to serve as a feasible and organised protocol for setting up the measurement and modelling work. This can be adapted in future assessments on light trespass issues under similar circumstances elsewhere, like scientific research, urban planning, or property development projects. [ABSTRACT FROM AUTHOR]

Phosphor converters with excellent thermal performance and high color rendering index (CRI) demonstrate vast application prospects in the field of laser diodes (LDs) lighting. Nevertheless, the significant heat accumulation within the converters and the absence of red spectral components pose challenges in achieving both a high saturation threshold and a high CRI for Y 3 Al 5 O 12 :Ce phosphor converters destined for white LDs. In this work, Mg 2 Al 4 Si 5 O 18 :Eu/Y 3 Al 5 O 12 :Ce (MAS:Eu/YAG:Ce) composite phosphor converters with excellent thermal performance and enhanced CRI were designed and fabricated for reflective laser lighting. Impressively, MAS:Eu/YAG:Ce phosphor-glass-ceramic composites (PGCC) retained a remarkable 97.8 % of the room temperature emission intensity at 150 °C. The reasons for this could be attributed to the strong thermal quenching resistance exhibited by MAS:Eu phosphors, as well as the ultra-thin glass bonding layer of about 150–200 μm. Meanwhile, by integrating the MAS:Eu/YAG:Ce PGCC with a 450 nm laser source, white LD devices operating in a remote excitation mode were fabricated. These white LDs demonstrated an improved CRI of 76 and maintained a low surface temperature of 131.7 °C under an ultra-high laser power density of 47.8 W/mm2 (laser power ∼ 4.70 W). Moreover, the maximum luminous flux and luminous efficiency of the white LDs were 484 lm and 103 lm/W, respectively. Therefore, the design of MAS:Eu/YAG:Ce composite phosphor converters offers a new approach for the development of high-power white LDs. [ABSTRACT FROM AUTHOR]

To address the problem of cyan-green light deficiency in fluorescent converters for laser diode (LD) illumination applications, Ca 3-x Sc 2 Si 3 O 12 :xCe3+ (CSS:xCe3+) cyan-green fluorescent ceramics and CSS:Ce3+ phosphor in glass (CSS:Ce3+-PiG) fluorescent converter were successfully prepared. Among them, the CSS:0.08Ce3+ cyan-green fluorescent ceramic and 20 wt% CSS:Ce3+-PiG fluorescent converter had the highest luminescence intensity. At 450 nm excitation, the emission spectra of both materials showed an asymmetric broadband band between 470 nm and 690 nm. And the two fluorescent converters are not appear of luminescence temperature quenching until more than 538 K. The performance of the white LDs synthesized with ceramic and PiG converters was investigated. Under different power excitation, the green emission intensity of both wLD is enhanced with increased incident laser power. The wLDs based on CSS:Ce3+ fluorescent ceramics have a luminous flux of 880 l m and the maximum luminescence efficiency of 176 l m/W at an incident power of 5 W. And the wLDs of PiG fluorescent converters have a maximum luminous flux of 584 l m and luminescence efficiencies of up to 117 l m/W. CSS:Ce3+ ceramics and CSS:Ce3+-PiG are green fluorescent converter with good luminescence performance and thermal stability. It will play an important role in the compensation of the cyan light in LD illumination. [ABSTRACT FROM AUTHOR]

The HELIOS (High Efficiency Light Intensity Observation System) project addresses the issue of excessive brightness from LEO satellite constellations. The system aims to develop a reflectance model of a satellite prior to launch, enabling the validation of compliance with astronomer guidelines, which suggest a minimum magnitude of 7. This ensures that the constellation is not visible to the naked eye and does not excessively interfere with astronomical observations. Additionally, the reflectance model obtained can be used for attitude determination by comparing the light curves with those obtained from observations. This application extends to Space Traffic Management, debris reentry prediction, and active debris removal. The system utilizes a light source consisting of 14 high-power LEDs with different wavelengths that replicate the solar spectrum. The light is positioned on an arc and can slide along a rail, allowing sampling at various angles. The arc itself can rotate on its axis, enabling the placement of the light source at any point on the hemisphere. At the center of the hemisphere, a scaled 3D printed model of the satellite under study is placed, with surface finishes resembling the actual satellite. Creating models with varying levels of detail permits to assess their impact on the reflectance model. Finally, the robotic arm Arm4NDO (Arm For Near Distance Observations) permits the movement of a high-efficiency quantum camera mounted at its end across the entire hemisphere's surface for data acquisition. The camera records a video, stopping at points of interest for capturing frames. To strike a balance between continuous data acquisition and reasonable testing times, both the light source and capture points are positioned every 15° in elevation and azimuth. The initial test campaign aimed to determine optimal camera settings (exposure, aperture, and ISO) to achieve good model visibility and a dark background. Preliminary tests focused on Starlink's chassis and the most significant observation configurations. Frames of interest were extracted from the videos, and their luminous flux (sum of pixel intensity values) was derived. With the obtained data, curves normalized relative to the maximum were plotted, allowing for a comparison of flux variations among different configurations. [ABSTRACT FROM AUTHOR]

4-probe measurements of surface resistivity, measurements of dark and light current-voltage characteristics, the possibilities of using a thin PdSi film to obtain perfect nano-sized ohmic contacts on the Si(111) surface have been investigated using Auger electron spectroscopy methods in combination with ion etching of the surface. It has been shown that the depth of Ni diffusion in the Ni-Si (111) system is 400 - 500 Å at indoor temperature, and 70 – 80 Å in the Ni-PdSi-Si (111) system. The quality of the ohmic contact in the latter case does not change up to T = 800 K and withstands luminous flux illumination up to F = 1100 lux. It is shown that the resistivity of the PdSi film passes through a minimum at T = 900 – 1000 K. An analysis of the results obtained will be given in the article. [ABSTRACT FROM AUTHOR]

Background: Wound healing monitoring and timely decision‐making are critical for wound classification. Tryptophan (Tr) intrinsic fluorescence, detected at 295/340 nm, provides a noninvasive approach for wound assessment. Our previous work demonstrated that this autofluorescence is associated with keratinocytes in a highly proliferative state in vitro. Objective: We investigated the correlation between Tr fluorescence and key wound healing parameters, including re‐epithelialization, fibrosis, neovascularization, and acute and chronic inflammation, using a rabbit model. Methods: Seven rabbits underwent wound healing assessment over a 15‐day period. We employed histological analysis from central and marginal biopsies, and UV fluorescence imaging captured by a monochromatic near‐UV sensitive camera equipped with a passband optical filter (340 nm/12 nm). Excitation was achieved using a 295 nm LEDs ring lamp. Normalized fluorescence values were correlated with histological measurements using Pearson correlation. Results: The UV fluorescence strongly exhibited a strong correlation with re‐epithelization (r = 0.8) at the wound edge, with peak intensity observed between the sixth and ninth days. Notably, wound‐healing dynamics differed between the wound center and edge, primarily attributed to variations in re‐epithelialization, neovascularization, and chronic inflammation. Conclusion: Our findings highlight the presence of autofluorescence at 295/340 nm during wound healing, demonstrating a robust association with re‐epithelialization. This excitation/emission signal holds promise as a valuable noninvasive strategy for monitoring wound closure, re‐epithelialization, and other biological processes where Tr plays a pivotal role. [ABSTRACT FROM AUTHOR]

For the purpose of achieving long-range, high-resolution, and ultra-wide-swath airborne earth imaging at extremely low-light levels (0.01 Lux), a low-light imaging system built on multi-detector optical butting was researched. Having decomposed the system's specifications and verified its low-light imaging capability, we proposed to employ an optical system with a large relative aperture and low distortion and achieve imaging through the field-of-view (FOV) butting facilitated by eight 1080P high-sensitivity scientific complementary metal-oxide semiconductor (SCMOS) detectors. This paper elaborates on the design concept of the mechanical configuration of the imaging system; studies the calculation method of the structural parameters of the reflection prism; provides mathematical expressions for geometric parameters, such as the length and width of the splicing prism; and designs in detail the splicing structure of six reflection prisms for eight-channel beam splitting. Based on the design and computational results, a high-resolution, wide-swath imaging system for an ambient illuminance of 0.01 Lux was developed. Exhibiting a ground sampling distance (GSD) of 0.5 m (at a flight height of 5 km), this low-light imaging system keeps the FOV overlap ratio between adjacent detectors below 3% and boasts an effective image resolution of 4222 × 3782. The results from flight testing revealed that the proposed imaging system is capable of generating wide-swath, high-contrast resolution imagery under airborne and low-light conditions. As such, the way the system is prepared can serve as a reference point for the development of airborne low-light imaging devices. [ABSTRACT FROM AUTHOR]

Ambient temperature has a significant effect on the electrical and luminous parameters of light-emitting diodes (LEDs), which include forward and reverse current, forward voltage, and luminous flux. This paper gives insight into the influence of ambient temperature on the electrical and luminous parameters of LEDs powered by a rectangular pulsed voltage source versus those powered by a constant voltage source. The characteristics of LEDs in LED lighting devices were studied to determine their optimal operating conditions. To this end, rectangular pulse voltages with different pulse filling factors D were considered against the DC voltage source. Characteristics were obtained for the current stabilization mode and for the LED voltage stabilization mode. In both modes, the temperature dependence of the luminous flux, current, voltage, power consumption, and luminous efficiency of the LEDs was studied in the 20 °C to 60 °C range. The optimal LED operating conditions were determined, of which their luminous flux and luminous efficiency are least dependent on ambient temperature. When powered by a rectangular pulse voltage, the LED device drivers' optimal pulse filling factor and operating frequency were determined. [ABSTRACT FROM AUTHOR]

It is expected that the activity of photocatalysts can remain the same or decrease as little as possible in photocatalysis reaction. Herein, for the first time, a self‐accelerating H2 production activity in a noble‐metal‐free Cu2O/TpPa‐2‐COF photocatalyst is reported. It shows a beginning H2 production rate of 4.41 mmol h−1 g−1 under visible light illuminance, while the activity kept increasing to 27.27 mmol h−1 g−1 after 25 h reaction, which is 6.2 times higher than the beginning activity and reaches a record high. It is confirmed that part of Cu2O in Cu2O/TpPa‐2‐COF in situ transformed to Cu0 in photocatalytic reaction, which acting as cocatalyst promotes the separation of photogenerated charge carriers. Further density functional theory calculations demonstrate that the Schottky barrier height of Cu‐Cu2O (111) interface is much smaller than that of Pt‐Cu2O (111), supporting its more efficient effect than that with Pt as cocatalyst. [ABSTRACT FROM AUTHOR]

The Greenhouse Gases Monitoring Instrument is based on the spectroscopic principle of spatial heterodyne spectroscopy technology and has the characteristics of no moving parts, a hyperspectral resolution, and a large luminous flux. The instrumental line shape function is one of the most important parameters characterizing the features of the instrument, and it plays a vital role in the system error analysis of the instrument's measurements. To accurately obtain the instrumental line shape function of a spatial heterodyne spectrometer during the on-orbit period and improve the accuracy of gas concentration retrieval, this study develops a method to model and characterize the characteristics of the instrumental line shape function, including modulation loss and phase error. This study employs the solar calibration spectrum in the 1.568–1.583 μm bands to conduct iterative calculations of the instrumental line shape function error model. After the instrumental line function is updated, the average relative deviation is reduced from 1.83% to 0.756% between the theoretical and measured solar spectra. Additionally, the average relative deviation is reduced from 7.049% to 2.106% between the GMI nadir and theoretical nadir spectra. The findings demonstrate that updating the instrumental line shape function mitigates the impact of variations in the spectrometer's instrumental line shape due to alterations in the orbital environment. This study offers a dependable reference for both the enhancement and oversight of a spectrometer's instrumental line shape function, along with an investigation of shifts in instrument parameters. [ABSTRACT FROM AUTHOR]

For the laser-driven lighting, traditional phosphor ceramics (PCs), such as Y 3 Al 5 O 12 : Ce3+ (YAG: Ce) PC and Lu 3 Al 5 O 12 : Ce3+ (LuAG: Ce) PC, usually show a wide "cyan cavity" due to the ultra-narrow emission bandwidth (∼2 nm) of the blue laser diode (LD). In this regard, the attainable color rendering (Ra) is always <90 even via the combination of "YAG: Ce/LuAG: Ce + CaAlSiN 3 :Eu2+". Evidently, the "cyan gap" is the bottleneck issue to attain high-color-quality laser-driven lighting. As such, we develop a novel cyan-green-emitting garnet-structured solid-solution Lu 3- x Sc x Al 2- y Sc y Al 3- z Sc z O 12 : Ce3+ (abbreviated as LuScAG: Ce) PCs, derived from the LuAG: Ce PC. A comparative study is conducted to unearth its microstructure, luminescence properties and promising availability. It can be found that the LuScAG: Ce PCs shows large full width at half maximum (FWHM) and abundant cyan emission. Upon material optimization, bright cyan-green emission can be generated with internal quantum efficiency (IQE) of 87.4 % and FWHM of 87.17 nm. Remarkably, this new material yields high-power emitting light with luminous flux (LF) of 3230 lm and luminous efficacy (LE) of 89.7 lm/W upon 36.0 W blue LD driven in rotatory excitation mode, which can serve as an efficient laser color converter. As expected, due to the achieved affluent cyan emissive components of developed LuScAG: Ce PCs, the lighting source based on "LuScAG: Ce PC + CASN: Eu phosphor-in-glass film (PiGF)" shows high color quality with Ra of 90.6 and R12 (related with the cyan cavity) of 85.0. [ABSTRACT FROM AUTHOR]

Laser‐driven white light exhibits exceptional brightness and directionality, making it particularly well‐suited for spotlight applications. Yet, attaining high‐quality white light remains challenging due to the sluggish heat dispersion and inconsistent light uniformity of color converters. In this study, an innovative phosphor‐in‐glass (PiG) film architecture is introduced, aiming to achieve superior quality laser‐driven light, where the traditional Y3(Ga,Al)5O12:Ce3+ (YAGG:Ce3+) PiG film is topped with a Al2O3‐in‐glass (AiG) film. The heightened thermal conductivity of the AiG film facilitates quicker dissipation of heat, consequently elevating the luminescence saturation threshold from 14 to 16 W mm−2 and luminous flux from 1243.8 to 1475.9 lm. The increased light scattering attributed to the AiG film also effectively disperses both laser and emitted light, significantly enhancing the angular consistency of color rendering index (Ra). This improvement is evident as the coefficient of variation (Cv) decreases dramatically from 16.69% to 0.25%. Moreover, by integrating CaAlSiN3:Eu2+ (CASN:Eu2+) into the PiG film and fine‐tuning the YAGG:Ce3+ and CASN:Eu2+ ratio, a high‐quality laser‐driven white light achieving an impressive color rendering index (Ra) of 88.7 and offering an adjustable correlated color temperature (CCT) has been developed. This innovation holds tremendous potential as a versatile spotlight solution for both indoor and outdoor settings. [ABSTRACT FROM AUTHOR]

In general, the algorithm for in‐cell ambient light and color temperature sensor was optimized by the golden modules. However, there are differences between the modules. This implies that if we do not normalize the data from modules, there will inevitably be a significant error. To this end, three calibration data methods for in‐cell integrated ambient light and color temperature sensor data are proposed. With these methods, the illuminance error rate can be reduced to less than 6% and the color temperature absolute error can be reduced to less than 150. [ABSTRACT FROM AUTHOR]

Differences in visual comfort between comfortable and uncomfortable luminance were explored on a smartphone. The results revealed that tiny changes in CFF and microsaccade parameters (pupil diameter, amplitude, and peak velocity) were presented at the comfortable luminance, inducing less eye discomfort. Particularly, CFF is an effective indicator of visual comfort and fatigue. [ABSTRACT FROM AUTHOR]