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In this work, novel Cr3+-doped near-infrared phosphors Y 3 Ga (3-x) ZnAO 12 (A = Ge, Si):xCr3+ were synthesized by the solid-phase reaction method. Their crystal structures and luminescence properties were studied. The excitation spectra of Y 3 Ga (3-x) ZnAO 12 (A = Ge, Si):xCr3+ at 453 nm and 632 nm correspond to the Cr3+ spin-allowed d-d transitions 4A 2g -4T 1g (4 F) and 4A 2g -4T 2g (4 F), respectively. The near-infrared emission peak observed at 783 nm (FWHM ≈ 130 nm) is induced by the 4T 2g -4A 2g transitions of Cr3+. Additionally, the luminescence performance of Y 3 Ga (3-x) ZnAO 12 (A = Ge, Si):xCr3+ phosphors were successfully enhanced by Si4+-Ge4+ ions substitution. The emitting intensities of Y 3 Ga 3 ZnGeO 12 :0.05Cr3+ and Y 3 Ga 3 ZnGe 0.8 Si 0.2 O 12 :0.05Cr3+ remain 56 % and 49 % at 423 K of their initial value at 298 K, respectively. The above results indicate that the excitation wavelengths of Y 3 Ga (3-x) ZnAO 12 (A = Ge, Si):xCr3+ phosphors match well with commercial 460 nm blue light chips, suggesting their potential applications in medical imaging, night vision and non-destructive testing. [ABSTRACT FROM AUTHOR]

Infrared microlens arrays (IR MLAs) are crucial for infrared imaging, target detection, and night vision, but creating high-quality large-scale IR MLAs is costly and challenging. This study presents a precision molding method to produce 500 × 500 microlenses on chalcogenide glass. The method involves creating concave silica molds with femtosecond laser-assisted chemical etching, which are then used to press convex MLAs onto the chalcogenide glass surface. By using single-pulse direct writing technology, a microlens array template containing 500 × 500 microlenses can be completed within 25 min. Meanwhile, the chemical etching method offers a highly efficient and low-cost way to prepare mold. The resulting MLAs exhibited smooth surfaces, uniform structures, and good imaging and focusing capabilities, indicating the effectiveness of this approach for large-scale MLA patterning and batch production. [ABSTRACT FROM AUTHOR]

The swift progress in portable spectrometer technology has fostered a widespread need for compact light sources. Concurrently, near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs), characterized by their low cost and compact structure, emerge as an optimal choice. Inspired by phase optimization through fluxes, we successfully synthesized pure phase Lu 3 Mg 2 GaSi 2 O 12 (LMGS):Cr3+, 3 wt%MgF 2 luminescent materials by incorporating various fluxes including LiF, NaF, MgF 2 , CaF 2 , SrF 2 and BaF 2. These materials emit broadband NIR light ranging from 620 nm to 1150 nm, with full width at half-maximums (FWHMs) exceeding 125 nm. By employing a dual-fluxes strategy to further enhance the luminescence intensity of Cr3+, the LMGS:3%Cr3+, 1 wt%NaF, 2 wt%MgF 2 sample exhibits a 2.45 times increase in emission intensity compared to the LMGS:3%Cr3+, 3 wt%MgF 2 sample. Concurrently, the quantum efficiency rises from 24 % to 46 %. Moreover, the integrated emission intensity of LMGS:3%Cr3+, 1 wt%NaF, 2 wt%MgF 2 retains at 75 %@425 K of its value at RT. Upon coupled with a 430 nm LED chip, the luminescent material exhibits an NIR output power of 43.8 mW@300 mA, indicating promising applications in rapid night identification, night vision and non-destructive testing. By adding different fluxes, the luminescence intensity of LMGS:Cr3+ is achieved a stepwise enhancement. [Display omitted] [ABSTRACT FROM AUTHOR]

Self‐powered near‐infrared (NIR) photodetectors are essential for surveillance systems, sensing in IoT electronics, facial recognition, health monitoring, optical communication networks, night vision, and biomedical imaging. However, silicon commercial detectors need external power to operate and cooling to suppress large dark currents. This work demonstrates a new class of CMOS‐compatible self‐powered NIR photodetector based on ferroelectric 5‐nm thick ZrO2 films which do not require cooling and therefore have two key advantages over Si, and at the same time have comparable performance metrics. At room‐temperature, under 940 nm wavelength illumination (1.4 mW cm−2 power density, 10 Hz repetition rate), and without any power applied, fast rise and fall times of ≈2 and 4 µs, respectively, are achieved in Al/Si/SiOx/ZrO2/ITO devices, along with responsivity, detectivity and sensitivity values of up to ≈3.4 A W−1, 1.2 × 1010 Jones and 4.2 × 103, respectively, far exceeding all other emerging self‐powered systems. Furthermore, dual‐band NIR detection is shown for different NIR wavelengths, proof‐of‐concept feasibility being demonstrated for the smart identification of NIR targets. Therefore, it is demonstrated, for the first time, that coupling together the pyroelectric effect, the photovoltaic effect, and the ferroelectric effect is a novel method to significantly enhance the performance of CMOS‐compatible ZrO2‐based self‐powered photodetectors in the NIR region. [ABSTRACT FROM AUTHOR]

Development of ultra‐broadband visible‐to‐near‐infrared (VIS‐NIR) luminescent materials is a challenging but rewarding endeavor, as they are highly desirable for a number of applications in photonics, optoelectronics, and biological sciences. Nevertheless, to date, rare earth‐doped phosphors that can be efficiently excited by blue light and produce broadband emission in the VIS‐NIR regions remain scarce. In this study, a series of Ce3+‐doped Ba3M4O9 (M = Sc, Lu, Y) broadband luminescent materials are designed based on low‐coordination crystallographic lattice engineering. Among these materials, Ba3Y4O9:Ce3+ produces a continuous ultra‐wide VIS‐NIR emission (λem = 660 nm) in the range of 500–950 nm under 410 nm light excitation. This emission wavelength is the longest among those observed in Ce3⁺‐doped oxide materials. Structural refinement, theoretical calculation, and spectral analysis demonstrate that this VIS‐NIR broadband emission is attributed to the occupying multiple distorted octahedral lattice sites by Ce3+ in Ba3Y4O9. Several strategies are employed to enhance the luminescence intensity and thermal stability of this material, including the use of carbon paper coating, the incorporation of co‐solvents, and the addition of GeO₂ or ZrO₂. Furthermore, the as‐prepared materials demonstrate multifunctional applications in white light‐emitting diodes (WLED), night vision, and fluorescent thermometers. This study offers insights into the design of Ce3+‐doped ultra‐wide VIS‐NIR light‐emitting materials. [ABSTRACT FROM AUTHOR]

Near-infrared phosphor converted light-emitting diodes (NIR pc-LEDs), as a state-of-the-art type of NIR sources, are finding multifaceted applications, where phosphor is a crucial component. In hope to provide new choices for NIR lighting, we synthesized in this work the two series of Ruddlesden -Popper type layered perovskite phosphors of SrLa 2 Al 2- x O 7 : x Cr3+ (x = 0–0.02) and SrLa 2- y Gd y Al 1.984 O 7 :0.016Cr3+ (y = 0–2), followed by detailed structure and luminescence investigation. SrLa 2 Al 2- x O 7 : x Cr3+ was found to emit ∼700–800 nm NIR light under UV excitation and be able to maintain ∼54.3 % of its room temperature intensity at 423 K, which is remarkably higher than those (∼25–30 %@423 K) of the Mn4+ activated perovskite NIR phosphors. Luminescence regulation was achieved by substituting La3+ with Gd3+, and it was revealed that Gd3+ may act as a sensitizer to significantly enhance Cr3+ luminescence (∼346 % at 77 K) through Gd3+ → Cr3+ energy transfer, which was confirmed by spectral and fluorescence lifetime analysis. The observed spectral features and the influence of Gd3+ were rationalized by considering crystal structure, local coordination, and crystal field. Finally, an NIR pc-LED device showing strong ∼700–900 nm luminescence was fabricated to show potential application of the phosphor in night vision and plant lighting. [ABSTRACT FROM AUTHOR]

Near-infrared phosphor-converted light-emitting diodes (NIR pc-LEDs) demonstrate a great prospect for applications in the field of bioimaging, modern agriculture, and nondestructive examination. Developing NIR emitting phosphor with high quantum efficiency (QE) and thermal stability is a significant issue. Herein, a novel highly efficient NIR-emitting phosphor Ca 2 YAl 2.95 Ge 2 O 12 :0.05Cr3+ is reported. Through chemical unit co-substitution of [Ca2+ + Ge4+] by [Al3+ + Y3+] in Ca 3 Al 1.95 Ge 3 O 12 :0.05Cr3+, when one-third of the Ca2+/Ge4+ sites were replaced by Y3+/Al3+, the internal and external QEs are 84.1 % and 38.6 %, respectively. Its emission peak was red-shifted to 780 nm compared with that of Ca 3 Al 1.95 Ge 3 O 12 :0.05Cr3+, which is in favor of matching with the absorption band of phytochrome P FR (600–800 nm). The Ca 2 YAl 2.95 Ge 2 O 12 :0.05Cr3+ phosphor shows high heat stability and its photoluminescence (PL) intensity at 423 K remains 80.38 % of that at 300 K. The photoelectronic conversion efficiency of the NIR pc-LED device fabricated by Ca 2 YAl 2.95 Ge 2 O 12 :0.05Cr3+ phosphor and 450 nm blue chip can reach 15.88 % at 180.5 mA drive current. All the results indicate that Ca 2 YAl 2.95 Ge 2 O 12 :0.05Cr3+ phosphor has excellent application potential in night vision and plant lighting. [ABSTRACT FROM AUTHOR]

Cr3+‐activated near‐infrared (NIR) emitting phosphors are considered as one of the most potential light‐conversion materials for NIR phosphor converted light‐emitting diodes (NIR pc‐LEDs). However, it is still a challenge for a single Cr3+ ion to achieve a flat ultra‐broadband emission toward multi‐functional spectroscopy applications. Herein, a chemical unit co‐substituting strategy is utilized to regulate the crystallographic occupancy of Cr3+ ions, and a flat ultra‐broadband NIR emission is successfully realized with a record emission wavelength of 915 nm in garnet‐type phosphors Ca3Sc2‐xHfxAlxSi3‐xO12: yCr3+ (0 ≤ x ≤ 1, 0.02 ≤ y ≤ 0.06), together with a large full width at half maximum (FWHM) regulation from 130 to 250 nm. The relation between the site occupation of Cr3+ ions in disordered [CaO8], [(Sc, Hf)O6] and [(Si, Al)O4] polyhedrons and the corresponding NIR emission are clarified by carefully evaluating the structural evolution, Raman spectra, electron paramagnetic resonance and time‐resolved emission lifetime spectra of Cr3+ ions. The corresponding crystal field strength of Cr3+ ions is investigated to further clarify the multi‐sites induced flat broadband NIR emission. Finally, a blue light pumped NIR pc‐LED is fabricated with a total output power of 37.58 mW and photoelectric conversion efficiency (PCE) of 13.67%@100 mA, which realizes the multi‐functional applications in night vision imaging, non‐destructive detection and palmprint vein recognition for assistant medical treatment. [ABSTRACT FROM AUTHOR]

Background: To prospectively evaluate binocular visual outcomes after implantation of trifocal intraocular lenses (IOLs) with high-water-content hydrophobic acrylic material in Japanese patients. Methods: In 59 patients (mean age 65.1 ± 7.9 years), Clareon PanOptix (CNWTT0: Alcon) with a high-water-content hydrophobic acrylic material was implanted bilaterally. Three months postoperatively, binocular uncorrected visual acuity (BUCVA) and distance-corrected visual acuity (BDCVA) at distances of 5 m, 80, 60, and 40 cm, binocular defocus curves, and binocular photopic contrast sensitivity were examined. Subjective symptoms (night vision disturbance, glare, halos, haze, or blurry vision) were also assessed. Results: The mean postoperative BUCVA/BDCVA at 5 m, 80 cm, 60 cm, and 40 cm were − 0.115/-0.163, -0.052/-0.047, -0.054/-0.075, and − 0.043/-0.067 logMAR, respectively. A smooth defocus curve, contrast sensitivity within the normal range, and acceptable subjective symptom rates were obtained. Conclusions: The trifocal IOL, composed of a high-water-content hydrophobic acrylic material, provides good continuous binocular vision from distance to near. Trial registration: This investigator-initiated study was registered in the Japan Registry for Clinical Trials (identifier: jRCTs032220042) on April 26, 2022. [ABSTRACT FROM AUTHOR]

Wildfires rank among the world's most devastating and expensive natural disasters, destroying vast forest resources and endangering lives. Traditional firefighting methods, reliant on ground crew inspections, have notable limitations and pose significant risks to firefighters. Consequently, dronebased aerial imaging technologies have emerged as a highly sought-after solution for combating wildfires. Recently, there has been growing research interest in autonomous wildfire detection using drone-captured images and deep-learning algorithms. This paper introduces a novel deep-learning-based method, distinct in its integration of infrared thermal, white, and night vision imaging to enhance early pile fire detection, thereby addressing the limitations of existing methods. The study evaluates the performance of machine learning algorithms such as random forest (RF) and support vector machines (SVM), alongside pre-trained deep learning models including AlexNet, Inception ResNetV2, InceptionV3, VGG16, and ResNet50V2 on thermal-hot, green-hot, and white-green-hot color images. The proposed approach, particularly the ensemble of ResNet50V2 and InceptionV3 models, achieved over 97% accuracy and over 99% precision in early pile fire detection on the FLAME dataset. Among the tested models, ResNet50V2 excelled with the thermalfusion palette, InceptionV3 with the white-hot and green-hot fusion palettes, and VGG16 with a voting classifier on the normal spectrum palette dataset. Future work aims to enhance the detection and localization of pile fires to aid firefighters in rescue operations. [ABSTRACT FROM AUTHOR]

The high‐precision visual perception results are easily affected by the lens flare issue when the image sensor is facing to strong light. The existing flare removal methods have poor robustness when confronted with flare interference caused by complex nighttime lighting, which has to preserve natural light source information. A simulated dataset for the removal of night flares is created to solve the problem of collecting complete paired training data, and night flare removal network (NFR‐Net) is proposed to remove the interference caused by various light disturbances at night. The light source extraction module is introduced to retain light source information realistically and effectively in night vision scenes. Extensive experimental results demonstrate that the proposed method is superior to the existing related methods in the various complex night vision scenes. The proposed NFR‐Net can enhance visual perception of nighttime images significantly and improve the performance of night vision tasks. [ABSTRACT FROM AUTHOR]

A novel Sb3+–Yb3+ co-doped Cs2NaScCl6 double perovskite with multimode luminescence and efficient excitation-dependent emission is proposed. Upon Sb3+–Yb3+ co-substitution in Cs2NaScCl6, NIR emission at 995 nm is greatly enhanced. A new STE emission peaking at 570 nm appears. Its great potential in anti-counterfeiting, LEDs and night vision is successfully demonstrated. [ABSTRACT FROM AUTHOR]

Fe3+‐doped MgGa2O4 (MGO: Fe3+) spinel‐type near‐infrared (NIR) phosphor with non‐toxicity, outstanding thermal stability, and tunable emission has recently gained great concern owing to its wide applications. Nevertheless, the existence of detrimental O defects in the MgGa2O4 host and the forbidden d‐d transitions of Fe3+ lead to unsatisfactory luminescence efficiency, limiting the commercial application. In this study, a vacancy repairing engineering has been innovatively developed via F− substitution in MGO: Fe3+ (MGOF: Fe3+) for significantly enhancing NIR emission and maintaining outstanding thermal stability. Specifically, F− substitution with a similar radius effectively repairs the intrinsic O vacancy defects of MGO, thereby prohibiting the detrimental electron‐capturing effect. Meanwhile, F− incorporation can make the lattice of MGO distort and break the forbidden transition of Fe3+. Significantly, the obtained MGOF: Fe3+ presents a 16‐fold higher emission intensity than that of MGO: Fe3+. More important, the MGOF: Fe3+ can remain at 91.17% (363 K) and 85.10% (423 K). Finally, the NIR emission of MGOF: Fe3+ can be used for night vision, non‐destructive biological tissue detection, and food analysis. The proposed vacancy repairing strategy can certainly stimulate some new thoughts and concepts in designing high‐performance phosphors for wider applications. [ABSTRACT FROM AUTHOR]

Although there has been a considerable amount of research on near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs), narrow-band emission and poor thermal stability continue to be problems associated with NIR phosphors. To solve these problems, La3ZrxSn1−xGa5O14:0.015Cr3+ phosphors with ultra-broadband NIR emission were obtained by partially replacing Sn4+ with Zr4+ through a strategy of multiple lattice site occupancy and cationic modulation, which altered the crystal field environment of the material. The spectrum was broadened, and the luminous intensity and thermal stability of the material were successfully improved. Finally, the phosphor was combined with a blue LED chip package, and the broad prospects of the phosphor in the NIR application field were proved by experiments of level detection, biomedical imaging, and night vision monitoring. [ABSTRACT FROM AUTHOR]

Nanomaterials have superior electronic, optical, and mechanical properties making them highly suitable for a range of applications in optoelectronics, biomedical fields, and photonics. Nanomaterials‐based IR detectors are rapidly growing due to enhanced sensitivity, wide spectral range, and device miniaturization compared to commercial photodetectors. This review paper focuses on the significant role of nanomaterials in infrared detection, an area critical for enhancing night vision and health monitoring technologies. The latest advancements in IR photodetectors that employ various nanomaterials and their hybrids are discussed. The manuscript covers the operational mechanisms, device designing, performance optimization strategies, and material challenges. This review aims to provide a comprehensive overview of the current developments in nanomaterial‐based IR photodetectors and to identify key directions for future research and technological advancements. [ABSTRACT FROM AUTHOR]

In extremely dark conditions, low-light imaging may offer spectators a rich visual experience, which is important for both military and civic applications. However, the images taken in ultra-micro light environments usually have inherent defects such as extremely low brightness and contrast, a high noise level, and serious loss of scene details and colors, which leads to great challenges in the research of low-light image and object detection and classification. The low-light night vision image used as the study object in this work has an excessively dim overall picture and very little information about the screen's features. Three algorithms, HE, AHE, and CLAHE, were used to enhance and highlight the image. The effectiveness of these image enhancement methods is evaluated using metrics such as the peak signal-to-noise ratio and mean square error, and CLAHE was selected after comparison. The target image includes vehicles, people, license plates, and objects. The gray-level co-occurrence matrix (GLCM) was used to extract the texture features of the enhanced images, and the extracted image texture features were used as input to construct a backpropagation (BP) neural network classification model. Then, low-light image classification models were developed based on VGG16 and ResNet50 convolutional neural networks combined with low-light image enhancement algorithms. The experimental results show that the overall classification accuracy of the VGG16 convolutional neural network model is 92.1%. Compared with the BP and ResNet50 neural network models, the classification accuracy was increased by 4.5% and 2.3%, respectively, demonstrating its effectiveness in classifying low-light night vision targets. [ABSTRACT FROM AUTHOR]

Achieving highly efficient absorption in the short wavelength infrared (SWIR) spectral region is crucial for advancing numerous technologies. SWIR absorption enhances energy harvesting in solar cells, improves the sensitivity of infrared sensors, and enables precise control of thermal radiative properties in thermal emission devices. These advancements are essential for applications such as thermal imaging, night vision, and thermophotovoltaic systems. The study presents a simple, cost‐effective design of a polymer‐coated multilayer perfect absorber (MPA) metamaterial optimized for the SWIR spectral region. The proposed MPA structure is composed of four distinct layers: a top layer made of polymethyl methacrylate (PMMA) polymer, a second layer featuring arrays of circular titanium nitride (TiN) disks, a dielectric middle layer consisting of a pure zinc oxide (ZnO) film, and a bottom metallic layer formed by a thin film of TiN. The results demonstrate that the MPA achieves near‐perfect absorption, with a remarkable 99% efficiency centered at a wavelength of 1.3 µm. The absorption properties are further investigated with respect to various structural parameters to ensure better performance of the absorber. These absorbers hold great promise for applications in energy absorption, infrared sensing, thermal emission, and related fields. [ABSTRACT FROM AUTHOR]

Near-infrared (NIR) persistent luminescence (PersL) materials have attracted extensive attention due to their great promise in medical diagnostics, bio-imaging, night vision surveillance, multi-level anticounterfeiting, and information encryption. To achieve NIR PersL (micro/nano-) materials with the desired properties, a variety of synthesis methods have been employed, including solid-phase reaction and liquid-phase synthesis. Different synthesis methods have different but important effects on the micro/nano-structure, luminescence, and PersL properties of the materials. Moreover, the influence of various synthesis methods on the properties of NIR PersL materials determines the selection of preparation approaches for other new material systems. Taking the representative NIR PersL ZnGa2O4:Cr3+ material as an example, four synthesis procedures are applied, namely, high-temperature solid-state reaction (SSR), high-temperature molten salt method (MSM), hydrothermal method (HM), and microwave-assisted solid-state (MASS) method. The structural and luminescent properties of samples made by SSR, MSM, HM, and MASS are compared. Notably, it is revealed that the MASS method can create additional trapping energy levels, which is of great significance for emerging applications. This work demonstrates the different effects of synthesis methods on PersL performance and provides a good guideline for the rapid and reasonable selection of preparation methods for diverse applications. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) phosphor‐converted light‐emitting diodes (pc‐LEDs) are considered as promising next‐generation light sources for optoelectronic and biomedical applications. Nevertheless, NIR phosphors with large bandwidths, long emission peaks, high external quantum efficiencies (EQEs) and valuable thermal stabilities are challenging to develop. Herein, this study reports a novel gallium germanate host, Ga3Al3Ge2O13 (GAGO), with a large bandgap and rigid host lattice for Cr3+ ion doping. The blue LED excitable GAGO:0.012Cr3+ phosphor can produce broadband NIR emission with a maximum intensity at 816 nm and a full‐width at half‐maximum (FWHM) of 187 nm. Notably, the phosphor also exhibits an excellent EQE of 35.8% and perfect thermal stability (I423 K/I298 K = 67.4%). Moreover, an attractive NIR afterglow duration of more than 24 h is achieved in the GAGO:0.004Cr3+ phosphor. The type and origin of the traps are discussed, and a possible long persistent luminescent (LPL) mechanism is proposed. Finally, an NIR pc‐LED based on a GAGO:0.012Cr3+ phosphor is fabricated. The results demonstrate that the obtained phosphors show great potential for use in night vision, nondestructive detection, bioimaging and information encryption. This study provides new insight into the development of broadband NIR luminescent materials with high efficiency, good thermal stability and extraordinary afterglow performance. [ABSTRACT FROM AUTHOR]

The luminescence property of various compounds is developed in the photoelectric applications field, while the near‐infrared (NIR) dual‐band emission of compounds is extremely challenging. Herein, 0D Cu(I)‐based organic–inorganic module (ETA)3Cu6I9 is synthesized to achieve NIR and cyan dual‐band emission in metal halide systems. Density functional theory (DFT) calculations combined with comprehensive spectroscopic data reveal its emission mechanism. Under the excitation at 371 nm, (ETA)3Cu6I9 shows the broadband NIR emission peaking at 775 nm with a large wavelength, attributed to the triple‐cluster‐center (3CC) transition. Meanwhile, under 286 nm excitation, (ETA)3Cu6I9 shows a bright cyan emission peaking at 490 nm, attributed to the metal‐to‐ligand charge transfer (MLCT) or halide‐to‐ligand charge transfer (XLCT) transitions. Moreover, (ETA)3Cu6I9 presents relatively superior thermal and air stability. Benefiting from the good stability of (ETA)3Cu6I9, the as‐fabricated NIR‐LED device demonstrates great potential in biological imaging and night vision. This study opens up a new way for designing new non‐toxic NIR and cyan dual‐band emission materials, which guides to synthesize new materials in metal halide field. [ABSTRACT FROM AUTHOR]

Broadband near-infrared (NIR) phosphor-converted light-emitting diodes (pc-LEDs) have become important as new NIR light sources in NIR spectroscopy and NIR imaging techniques. However, currently developed broadband NIR phosphors commonly suffer from weak emission and poor thermal stability. In this work, a series of Gd 3 Lu 2 Ga 3 O 12 : Cr3+ phosphors were synthesized via high-temperature solid-state reaction. Under 460 nm excitation, the phosphors exhibit an intense emission spanning from 650 to 1150 nm with a full width at half maximum (FWHM) of 122 nm. After introducing Yb3+ as a co-dopant, the emission of the phosphor has been broadened greatly. Interestingly, the studied phosphors demonstrate super high thermal stability in a wide temperature range of 35–560 K, with the integrated emission intensity fluctuating within 10 %. At 435 K, the emission intensity of Gd 3 Lu 2 Ga 3 O 12 : 0.03Cr3+ remains 99.5 % and Gd 3 Lu 2 Ga 3 O 12 : 0.03Cr3+, 0.01 Yb3+ keeps 102.7 % of the initial intensity at room temperature. These NIR phosphors have been encapsulated with a common commercial 460 nm blue LED chip to fabricate a pc-LED device. The NIR output power of the device reaches 23.93 mW@100 mA, with a photoelectric conversion efficiency of 9.81 % at 20 mA current. The applications of the prepared NIR light source in night vision, and bioimaging have been demonstrated. The results show that these Cr3+/Yb3+ doped garnet phosphors can be effectively used in NIR light sources. [ABSTRACT FROM AUTHOR]

The luminescence in NIR-II and NIR-III ranges has high penetration, as well as lower scattering and absorption in biological tissues. It is crucial to develop phosphors with strong emissions covering both spectral ranges. A novel Cr3+-Yb3+-Er3+ activated KScP 2 O 7 phosphate phosphor has been reported in this work, which shows emission within the range from 800 to 1650 nm, covering both NIR-II and NIR-III regions, with a quantum efficiency of 35%. Effective Cr3+ → Yb3+, Cr3+ → Er3+, and Yb3+ → Er3+ energy transfers were confirmed. Near-infrared optical thermometry was also developed utilizing the non-thermally coupled 4I 13/2 → 4I 15/2 (Er3+) and 2F 5/2 → 2F 7/2 (Yb3+) levels, whose highest relative sensitivity (S R), and absolute sensitivity (S A) values were determined as 0.75% K−1 (348 K) and 84.6 × 10−4 K−1 (373 K), respectively. The KScP 2 O 7 : 0.05Cr3+, 0.02Yb3+, 0.01Er3+ phosphor was blended with a commercial low-cost blue LED chip (465 nm) in order to develop NIR-based pc-LED devices, and the highest recorded output power with a value of 38.0 mW (320 mA) was achieved in the studied range. A photoelectric efficiency of 5.9% (10 mA) was also obtained in the NIR region. Through screen printing, the developed phosphor was also proven to be suitable for night vision. This study provides a novel tri - doping approach to design blue light excitable phosphors simultaneously emitting strong NIR-II and NIR-III lights. [ABSTRACT FROM AUTHOR]

This narrative review synthesizes recent basic and clinical research on visual disturbances in low-light environments, highlighting the evaluation techniques for these conditions. It focuses on the degradation of visual acuity under dim lighting, exacerbated by pupil dilation, known as night vision disturbance (NVD). Key contributors to NVD include optical scattering, intraocular diffraction, ocular aberrations, and uncorrected refractive errors, all significantly impacting quality of life and functional abilities. This review also examines the effects of aging, eye disorders, surgical interventions, and corneal irregularities on NVD. It details the definitions, distinctions, and measurement methodologies for various optical phenomena, using both objective and subjective approaches, such as visual function questionnaires, simulators, and the light disturbance analyzer (LDA). The LDA is validated for clinical characterization and quantification of light distortion, proving useful in both clinical and research settings. This review advocates for continued innovation in therapeutic interventions to improve patient outcomes and alleviate the impact of visual disturbances. [ABSTRACT FROM AUTHOR]

High‐power broadband near‐infrared (NIR) light sources have received extensive attention in long‐distance night vision lighting, non‐invasive detection and imaging, and quantitative analysis of organic components. However, developing targeted NIR‐emitting phosphors with high external quantum efficiency (EQE) and thermal stability remains a challenge to raise the NIR output power and expand the applications. Herein, Ga1.98−xScxO3:0.02Cr3+ luminescent ceramics are prepared with redshifted emission peaks from 710 to 820 nm depending on the weakened crystal field. The optimized Ga1.18Sc0.8O3:0.02Cr3+ ceramic exhibits a high EQE of 79.6% and excellent thermal stability (I423 K/I298 K = 72%) under 468 nm excitation, which brings a saturation threshold up to 893 mW@3 W mm−2 under 450 nm laser pumping. The high‐power laser‐driven broadband NIR light source demonstrates potential in non‐invasive detection and quantitative analysis of alcohol concentration. This study opens up new avenues for the exploration of high‐power broadband NIR light sources. [ABSTRACT FROM AUTHOR]

Persistent luminescence materials have been widely studied due to their excellent optical properties. However, they can only be activated by UV light; in other words, the charging method for these phosphors is limited. In fact, materials that can continuously emit light when exposed to sunlight are highly sought after for their potential to reduce energy consumption. Warm‐colored persistent luminescence materials are particularly useful for information storage, security marking, and preventing counterfeiting. Nevertheless, creating effective warm‐color persistent luminescence materials that are activated by sunlight remains a challenging task. To address this issue, novel daylight‐activated red persistent luminescence materials, Gd3‐xCax‐0.02GaO6:0.02Eu2+ (x = 0.3 ‐ 0.7) are explored. The material can be effectively activated by sunlight under all weather conditions, as well as by bright light from indoor lamps, mobile phone screens, and any form of visible light. Moreover, it possesses excellent water resistance. The process of electron trapping and release within the material is investigated through thermoluminescence experiments, photoluminescence spectra, and persistent luminescence spectra. Importantly, this phosphor has been demonstrated for various applications, including night vision marking, anti‐counterfeiting, optical information storage, and positioning, among others. [ABSTRACT FROM AUTHOR]

Near-infrared transparent films demonstrate important applications in many fields, but how to eliminate light interference from ultraviolet-visible region and how to tackle the trade-off effect between film thickness and transmittance remain as challenges. Herein, we report a near-infrared transparent film that achieves high-efficient combination of thin thickness (16 μm), suitable cut-off wavelength (890 nm), and ideal transmittance (TNIR > 90%, TVis < 1%). Moreover, the film is photo-chemically stable, heating resistance and moisture insensitive. The key component of the film is a complex of a specially designed boron compound containing a perylene monoimide unit (PMI-CBN) with an organic base 1,8-diazabicyclo[5,4,0]undec-7-ene. The complex depicts red-shifted absorption from 709 to 943 nm owing to deprotonation of the N-H group of PMI-CBN. Dispersion of the complex in polymethyl methacrylate results in the high-performance film. As demos, the film is successfully used for night vision imaging and information encryption. Near-infrared transparent films have a number of applications, but combining elimination of UV-vis light and the balance of film thickness and transmittance is challenging. Here, the authors report the development of a thin material with good transmittance and a suitable wavelength cutoff. [ABSTRACT FROM AUTHOR]

Inherited retinal diseases (IRDs) encompass a wide spectrum of rare conditions characterized by diverse phenotypes associated with hundreds of genetic variations, often leading to progressive visual impairment and profound vision loss. Multiple natural history studies and clinical trials exploring gene therapy for various IRDs are ongoing. Outcomes for ophthalmic trials measure visual changes in three main categories—structural, functional, and patient-focused outcomes. Since IRDs may range from congenital with poor central vision from birth to affecting the peripheral retina initially and progressing insidiously with visual acuity affected late in the disease course, typical outcome measures such as central visual acuity and ocular coherence tomography (OCT) imaging of the macula may not provide adequate representation of therapeutic outcomes including alterations in disease course. Thus, alternative unique outcome measures are necessary to assess loss of peripheral vision, color vision, night vision, and contrast sensitivity in IRDs. These differences have complicated the assessment of clinical outcomes for IRD therapies, and the clinical trials for IRDs have had to design novel specialized endpoints to demonstrate treatment efficacy. As genetic engineering and gene therapy techniques continue to advance with growing investment from industry and accelerated approval tracks for orphan conditions, the clinical trials must continue to improve their assessments to demonstrate safety and efficacy of new gene therapies that aim to come to market. Here, we will provide an overview of the current gene therapy approaches, review various endpoints for measuring visual function, highlight those that are utilized in recent gene therapy trials, and provide an overview of stage 2 and 3 IRD trials through the second quarter of 2024. [ABSTRACT FROM AUTHOR]

Latent fingerprint (LFP) detection is an important tool in criminal offense detection. Nowadays, ultraviolet (UV) excited visible emission phosphors are widely used in LFP detection; however, due to the shortcomings of UV excitation (λex < 270 nm) such as low power, high price, and susceptibility of visible light to the influence of natural light, their application in LFP detection is restrained. Here, a new idea is proposed: the use of blue light-excited near-infrared (NIR) emitting phosphors as a tool for fingerprint detection visualization. To this end, in this work, a series of blue-excited (λex = 467 nm) NIR phosphors Ca(1−x)SrxO:Eu2+ (x = 0–0.2) were designed based on CaO:Eu2+ by using the crystal field engineering strategy. When x = 0.2, the luminescence center is red-shifted from 733 nm to 783 nm, and the full width at half maximum (FWHM) is broadened from 100 nm to 156 nm, and the red-shift and broadening of the spectrum greatly improve the accuracy of fingerprint detection. Finally, Ca0.8Sr0.2O:0.1%Eu2+ gives high-quality visualized fingerprints in LFP detection, which is a good solution to the problems faced by UV-excited visible-emitting phosphors in LFP detection. Not only that, a NIR phosphor-converted light-emitting diode (NIR pc-LED) was prepared by combining Ca0.8Sr0.2O:0.1%Eu2+ with a blue LED chip, which was verified to have the potential for applications in biological tissue penetration and night vision illumination. This work introduces a new idea for the detection of a LFP and demonstrates that rationalizing the local structure around Eu2+ is an effective strategy for exploring Eu2+-doped NIR luminescent phosphors. [ABSTRACT FROM AUTHOR]

Broadband near-infrared (NIR) light sources cover unique optical wavelengths and are valuable in the fields of bioimaging and photodynamic therapy, night vision lighting and security monitoring. NIR phosphor converted light-emitting diode (NIR pc-LED) devices have attractive features such as tunable emission peak, low cost of production, compact in sizes and high luminous efficiency. However, heat accumulation during operation due to poor thermal conductivity of the organic resin used in packaging often causes serious reduction in luminous efficiency and accelerated degradation of the device. In present work, we developed a Cr3+-doped transparent CaF 2 -based oxy-fluoride glass-ceramic (GC) that showed a broadband emission of 700∼1400 nm under 470 nm excitation. The emission peaked at ∼880 nm, the full-width at half maximum was about ∼297 nm, and the photoluminescence quantum yield reached ∼31.19 %. The emission was derived from the electronic transition of Cr3+ ions from the 4T 2 (F) to 4A 2 (F). Through structural analysis and numerical simulation, we showed that during the heat treatment process, Cr3+ ions were enriched into the CaF 2 crystal phase and replaced the Ca2+ in the GC host with occupied the center position of the polyhedrons, which provided a weak crystal field and led to NIR emission. We built NIR pc-LED devices using optimized GC and commercial blue LED chips, and we demonstrated the application of this NIR pc-LED in night-vision lighting. Our approaches to prepare simple and stable inorganic NIR luminous materials sealed in bulk in a transparent CaF 2 -based oxy-fluoride GC and to construct pc-LED devices could provide new concept to the field and have practical implications to applications in related fields. [ABSTRACT FROM AUTHOR]

Introduction. Posterior fossa tumours (PFTs) frequently present with ophthalmic complaints. The literature is mainly focused on PFTs affecting the pediatric age group, and the post-treatment visual outcomes (VOs) are scarcely reported. Objective. To evaluate the VOs at 6 months following the index surgery in patients with PFTs. Materials and methods. This retrospective study involved 50 patients of all age groups who underwent surgical resection of PFTs in the Department of Neurosurgery. The patients with PFTs, except those with low-grade tumours, received concurrent chemo-radiotherapy. Pre- and postoperative (6 months after the index surgery) ophthalmic examinations were done and compared. VOs included colour vision, night vision, visual acuity (VA), pupillary function (size, reactivity), papilledema grade, splinter haemorrhage, retinal venous dilatation, strabismus (esotropia and hypertropia), and nystagmus. Results. The patients were mainly aged 1-10 years (22%) with slight female predominance (52%). The most common PFTs were brainstem glioma and pilocytic astrocytoma (each 18%). At 6 months, there was no significant change in colour and night vision, pupil size and reactivity, splinter haemorrhage, and hypertropia (all pvalues> 0.05). A significantly lesser proportion of patients had moderate VA (pvalue= 0.013), retinal venous dilatation (p-value=0.001), and grade 1 (p-value=0.005) as well as grade 4 papilledema (p-value=0.041). Moreover, a significantly greater proportion of patients had grade 0 papilledema (p-value<0.0001). While the incidence of nystagmus and esotropia increased significantly (both p-values<0.0001). Conclusion. At 6 months, the majority of the patients had good VOs, including significant improvement in moderate VA, papilledema, and retinal venous dilatation. While nystagmus and esotropia increased significantly. [ABSTRACT FROM AUTHOR]

Although bats are notorious for their association with poison, they are genuine teachers and friends to humans. They play indispensable ecological roles in pest control, seed dispersal, and plant pollination, and hold significant economic value. Furthermore, they are crucial for research in health and longevity, as well as in biomimetics. As the only flying mammals, bats have always been subjects of human observation and study. The discovery of the bat sonar system illustrates the complex and persistent human quest for truth. Bats possess the extraordinary ability of echolocation, which has inspired the creation of bat robots. The future applications and development prospects for these technologies are vast. Additionally, bats are a symbol of good fortune in Chinese culture, deserving of our eternal praise. This paper discusses the advantages and disadvantages of bats, their body structure, living habits, night vision abilities, and the related knowledge of bat robots. The aim is to guide students to comprehensively and critically understand bats, cultivate critical thinking skills, appreciate the marvels of biomimicry, inherit the essence of traditional Chinese good fortune culture, and establish the concept of harmonious coexistence between humans and nature. [ABSTRACT FROM AUTHOR]

Key Clinical Message: Herein, we report a rare case of nyctalopia diagnosed in the first trimester of pregnancy due to vitamin A deficiency as a result of a bariatric gastrectomy. Low serum vitamin A levels establish the diagnosis and the patient was treated with oral vitamin A supplements. Moreover, due to the teratogenic effects of exceed Vitamin A levels in early pregnancy, supplements' dosages should be prescribed with respect to the safe limits. Our case aims to highlight the importance of checking micronutricients and vitamins levels before and during pregnancy in women that had a previous bariatric surgery. Vitamin A deficiency (VAD) has been identified as the predominant factor in the development of night blindness during pregnancy, a high‐risk for morbidity situation. Herein, we report a rare case of nyctalopia diagnosed in the first trimester of pregnancy due to VAD as a result of a bariatric gastrectomy. Our case aims to highlight the importance of checking micronutricients and vitamins levels before and during pregnancy in women that had a previous bariatric surgery. Low serum vitamin A levels establish the diagnosis and the patient was treated with oral vitamin A supplements. An uneventful antenatal course resulted in the birth of a healthy live neonatal at 38 weeks of gestation. In conclusion, nyctalopia is a rare condition in pregnant women that is often caused by VAD that poses significant health risks for both the mother and the infant, especially in women with a history of gastrointestinal bypass surgery, or any factors leading to malnutrition. Clinicians have to be alerted for micronutrients deficient in pregnant women who have a bariatric operation in their medical history. [ABSTRACT FROM AUTHOR]

In recent years, near-infrared (NIR) phosphors have attracted great research interest due to their unique physical properties and broad application prospects. However, obtaining NIR phosphors with both high quantum efficiency and excellent thermal stability remains a great challenge. In this study, novel NIR Ca3Mg2ZrGe3O12:Cr3+ phosphors were successfully prepared using a high-temperature solid-phase method, and the structure and luminescent properties of the material were systematically investigated. Ca3Mg2ZrGe3O12:0.01Cr3+ emits NIR light in the range of 600 to 900 nm with a peak at 758 nm and a half-height width of 89 nm under the excitation of 457 nm blue light. NIR luminescence shows considerable quantum efficiency, and the internal quantum efficiency of the optimized sample is up to 68.7%. Remarkably, the Ca3Mg2ZrGe3O12:0.01Cr3+ phosphor exhibits a near-zero thermal quenching behavior, and the luminescence intensity of the sample at 250 °C maintains 92% of its intensity at room temperature. The mechanism of high thermal stability has been elucidated by calculating the Huang Kun factor and activation energy. Finally, NIR pc-LED devices prepared from Ca3Mg2ZrGe3O12:0.01Cr3+ phosphor with commercial blue LED chips have good performance, proving that this Ca3Mg2ZrGe3O12:0.01Cr3+ NIR phosphor has potential applications in night vision and biomedical imaging. [ABSTRACT FROM AUTHOR]

Purpose: To compare early visual quality of small incision lenticule extraction (SMILE) versus laser in situ keratomileusis (LASIK) in terms of low contrast acuity. Methods: A secondary analysis was performed using a harmonized dataset derived from two completed prospective cohort studies on active-duty military service members undergoing either SMILE (n = 37), wavefront-guided (WFG) LASIK (n = 51), or wavefront-optimized (WFO) LASIK (n = 56). Night vision and photopic and mesopic low contrast visual acuity (LCVA) up to 3 months postoperatively were compared between groups. Results: Compared to SMILE-treated eyes, WFG LASIK–treated eyes had significantly better night vision and photopic LCVA at 1 month postoperatively (beta = −0.039, P =.016; beta = −0.043, P =.007, respectively). WFO LASIK–treated eyes had significantly better photopic LCVA at 1 month postoperatively (beta = −0.039, P =.012) but had worse mesopic LCVA at 3 months postoperatively (beta = 0.033, P =.015) versus SMILE-treated eyes. Conclusions: SMILE and LASIK, on either a WFG or WFO laser platform, yielded excellent outcomes, but LCVA seemed to recover quicker following LASIK compared to SMILE. [J Refract Surg. 2024;40(9):e667–e671.] [ABSTRACT FROM AUTHOR]

In this paper, a neutral copper iodide hybrid with unique Cu3I3 trimeric inorganic functional unit is successfully fabricated using 5,6,7,8‐tetrahydroquinoxaline (L) with large steric‐hindrance group as the organic ligand. The hybrid owns a one‐dimensional (1D) extended polymeric structure in the form of Cu3I3(L)2. As a CuI‐based hybrid, 1D‐Cu3I3(L)2 has an infrequent far‐red/near‐infrared emission, exhibiting the potential application prospects in the field of display and night vision. Moreover, the luminescence mechanism is carefully studied by decay lifetime measurement and calculation of density of states, which is verified to be the combination of metal‐to‐ligand charge transfer and halide‐to‐ligand charge transfer. [ABSTRACT FROM AUTHOR]

Simple Summary: The behaviours and needs of nocturnal animals can be overlooked by humans, potentially because of our poor night vision and diurnal waking hours. Despite certain challenges in studying many nocturnal animals, appropriate provisions for their welfare should be supported in both wild and managed environments. To investigate this issue and explore ways to offer technology-enhanced welfare, husbandry practices and enrichment opportunities for nocturnal species, we conducted a multidisciplinary workshop (Moon Jam). During the event, species experts provided animal welfare briefs that related to specific challenges for nocturnal animals in different contexts. Teams of participants addressed these challenges in collaborative design sessions, producing a collection of hand-crafted models to share their ideas. An important aspect of the workshop was to be inclusive of all the stakeholders involved, including zoo management teams, animal stewards and zoo visitors, as well as the individual species. In this paper, we present our reflections on managed nocturnal animal welfare, framing these within current practices and Moon Jam workshop outputs. We contribute a set of guidelines for those involved with caring for zoo-housed nocturnal species, emphasizing the provision of technology-enhanced husbandry and enrichment opportunities. This paper addresses the potential for technology to support husbandry and enrichment opportunities that enhance the welfare of zoo and sanctuary-housed nocturnal and crepuscular species. This topic was investigated through the medium of a multidisciplinary workshop (Moon Jam) that brought together species experts, zoo designers, Animal-Computer Interaction researchers and post-graduate students in collaborative discussions and design sessions. We explain the context through an examination of existing research and current practices, and report on specific challenges raised and addressed during the Moon Jam, highlighting and discussing key themes that emerged. Finally, we offer a set of guidelines to support the integration of technology into the design of animal husbandry and enrichment that support wellbeing, to advance the best practices in keeping and managing nocturnal and crepuscular animals. [ABSTRACT FROM AUTHOR]

Lead‐free double perovskites with multi‐mode emission characters are highly desired for optoelectronic devices. Herein, dual‐mode thermal responses with low thermal quenching in the red emission channel and high thermal quenching in the near‐infrared (NIR) channel are achieved in a holmium‐based double perovskite (Cs2NaHoCl6). The temperature‐dependent emission is modulated by manipulating three cross relaxations of CR1 (5F4, 5I7) → (5F5, 5I6), CR2 (5S2, 5I8) → (5F5, 5I7), and CR3 (5F5, 5F5) → (5I7, 5G4) through adjusting the concentration of Ho3+. The difference in thermal response between the red and NIR emissions becomes more pronounced with a higher concentration of Ho3+ up to 100%, while the two emissions show almost the same thermal quenching behavior when the Ho3+ concentration is below 20%. To demonstrate their applications, a thermal‐responsive dual‐mode information encryption system and a NIR emitting LED with night vision capacity are fabricated using the prepared samples. This study provides a new approach for thermal quenching regulation in rare‐earth‐based lead‐free perovskites and illustrates their potential in lighting, anti‐counterfeiting, and sensing applications. [ABSTRACT FROM AUTHOR]

Fe3+ ions as near‐infrared (NIR) activators are emerging as an alternative to Cr3+.1–5 However, it is a challenge to develop Fe3+‐activated NIR phosphors featuring tunable optical properties, high efficiency, and thermal stability. Herein, we present a series of near‐unity internal quantum efficiency (IQE), wavelength‐tunable and thermal stability NIR‐emitting phosphors Sr2−yCaySc1−xSbO6:xFe3+ (S2−yCyS1−xS:xFe3+). Sr2ScSbO6:1%Fe3+ (SSS:1%Fe3+) phosphor shows broadband NIR emission at 904 nm and near‐unity IQE under excitation at 300 nm. Experimental and theoretical calculation results demonstrate that introduced Ca ions could increase the bandgap value and Debye temperature (ΘD) of host from Eg = 3.702 eV, ΘD = 609 K of y = 0 to Eg = 3.801 eV, ΘD = 692 K of y = 2. Significantly, the resultant S2−yCyS1−xS:1%Fe3+ NIR phosphors show wavelength‐tunable emission from 904 to 952 nm and high IQE of 84.6%–97.5% as well as enhanced thermal stability (I423K/I298K = 76.9%) of Ca2ScSbO6:1%Fe3+ (CSS:1%Fe3+) in comparison with that (I423K/I298K = 70.6%) of pristine sample. We fabricated an NIR light‐emitting diodes (LED) device by using CSS:1%Fe3+ NIR phosphors with ultraviolet LED chip and demonstrated its potential applications in anticounterfeiting, information encryption, and night vision. [ABSTRACT FROM AUTHOR]

The performance of the near‐infrared phosphor‐converted light‐emitting diodes (NIR pc‐LEDs) mainly depends on the NIR emitting phosphors used. Cr3+ doped materials can be excited by blue light chips, but their emission is located in the NIR‐I region (650–1000 nm). Ni2+ doped materials are mainly located in the NIR‐II region (1000–1700 nm), but they cannot be effectively excited by blue light chips. Herein, Cr3+, Ni2+ mono‐doped, and co‐doped Sr2GaTaO6 NIR emitting phosphors are prepared and investigated. Cr3+ and Ni2+ ions occupy two octahedral sites of Ga3+ and Ta5+. The co‐doping of Cr3+ ions has achieved two breakthroughs. One is to shift the optimal excitation wavelength from violet light to blue light due to the energy transfer (efficiency up to 70%) from Cr3+ to Ni2+. The other is to achieve the broadband and continuous emission across NIR‐I and NIR‐II regions (650–1700 nm, with a full width at half maximum (FWHM) of 410 nm (173 nm + 237 nm)). The prepared Sr2GaTaO6: 0.02Cr3+, 0.01Ni2+ phosphor is combined with a commercial 460 nm blue chip to realize its application in organic compounds identification, night vision, and biological imaging. This work points out a direction for the future development of efficient super broadband NIR‐emitting phosphors. [ABSTRACT FROM AUTHOR]

Near‐infrared (NIR) phosphors are a vital component of phosphor‐converted light‐emitting diodes (pc‐LEDs), with simultaneous high quantum efficiency and thermal stability being essential attributes for optimal performance. In this paper, a novel ZnAlB(1‐x)GaxO4:0.05Cr3+ system is designed by gradually substituting B with Ga. Surprisingly, a significant enhancement in photoluminescence performance is observed, reaching peak efficiency at x = 1. Further development led to a series of ZnAlGaO4:yCr3+ (ZAGO:yCr3+) phosphors, exhibiting variable full width at half maximum (FWHM) ranging from 32 to 163 nm with increasing Cr3+ content, attributed to energy transfer between two Cr3+ emission centers. Among these, ZAGO:0.05Cr3+ emerges as the optimal phosphor, boasting a high internal/external quantum efficiency of 80%/34% with a FWHM of 80 nm. Notably, this phosphor demonstrates anti‐thermal quenching behavior (125.53% @ 423 K), with its exceptional thermal stability elucidated through the defect level model. The fabricated NIR pc‐LEDs featuring ZAGO:Cr3+ phosphors show great prospect in multifunctional applications in plant cultivation, night vision, non‐destructive analysis and veins imaging. [ABSTRACT FROM AUTHOR]

Laser diode (LD)‐pumped phosphor‐converted near‐infrared (NIR) lighting source predicts a “brighter” future for active imaging and non‐destructive detection, with improved imaging resolution and detection accuracy to expand more application scenarios. To meet a variety of requirements for LD‐pumped phosphor color converters, herein, a novel CaLu2Mg2Si3O12:Ce3+, Cr3+, Nd3+ (CLMS:Ce3+, Cr3+, Nd3+) phosphor‐in‐glass film (PiGF) sintered on sapphire substrate (SP) composite is fabricated. By introducing a rapid infrared firing technique, the good luminescence properties of phosphor powders are maintained in the PiGF due to the trivial thermally‐aggressive effect of glass components on phosphor particles. The multiple energy transfers (ETs) among Ce3+, Cr3+, and Nd3+ enhance the NIR luminescence of Cr3+ and Nd3+, and simultaneously extend the spectral range to cover the NIR‐I and NIR‐II regions. The luminescent behaviors of samples are carefully examined under different laser excitation modes to gain more insights into laser‐matter interaction. A watt‐level output is achieved by applying appropriate thermal and optical management. A comparative study is performed on the luminescence saturation mechanism of CLMS:Ce3+, Cr3+, Nd3+ PiGF showing different contributions of thermal quenching and intensity quenching among these three ions. Finally, the application presentations confirm the great potential in the fields of long‐distance night vision and high‐resolution biological imaging. [ABSTRACT FROM AUTHOR]

Cr3+ ions doped broadband emission near‐infrared (NIR) phosphors are pertinent to widespread emerging applications and get rapid developed. However, it remains a challenge to simultaneously achieve highly efficient and broadband near‐infrared emission in Cr3+ ions doped phosphors. Herein, the Cr3+ ions firstly doped into organic–inorganic hafnium chlorine TEA2HfCl6 (TEA = Tetraethylammonium, C8H20N), which show broadband emission at a range of 700–1300 nm, a full width at half maximum (FWHM) of 164 nm, and a high photoluminescence quantum yield (PLQY) of 60%. The organic–inorganic metal halides show huge advantages than traditional inorganic phosphors, like high luminescence efficiency, low temperature solution synthesis progress, and low cost, which provide an efficiency strategy for lighting industry. Based on these advantages, a high power NIR light emitting diode (LED) is fabricated by TEA2HfCl6:Cr3+ with a high‐power 530 nm chip, which is used in food analysis, night vision, and biomedical imaging as a demonstration. This work indicates the feasibility of organic–inorganic metal halides as host materials for developing Cr3+ ions emitting phosphor toward multi‐optoelectronic applications. [ABSTRACT FROM AUTHOR]

Slow or failed detection of low-salience vertical obstacles and associated wires is one of today's leading causes of fatal helicopter accidents. The risk of collisions with such obstacles is likely to increase as advanced aerial mobility and broadening drone activity promises to increase the density of air traffic at low altitudes, while growing demand for electricity and communication will expand the number of vertical structures. The current see-and-avoid detection paradigm relies on pilots to spend much of their visual attention looking outside for obstacles. This method is inadequate in low-visibility conditions, cluttered environments, and given the need for pilots to engage in multiple competing visual tasks. With the expected growing number of hazards and an increased traffic volume, the current approach to collision avoidance will become even less tenable. A human-in-the-loop helicopter simulator study was conducted to assess the effectiveness of sensor visualizations (image intensification or thermal imaging) and graphic augmentations (a bounding box around a tower and a circle surrounding the base of the tower) for supporting fast and reliable detection of vertical structures. Graphic augmentations resulted in faster tower detection time when ambient visibility and illumination were reduced close to the limit for visual flight. Bounding boxes around towers were detected first in all conditions but tended to mask the obstacle they were meant to highlight. Sensor visualization affected tower detection time only at night, where night vision goggles were more effective than the infrared thermal sensor. [ABSTRACT FROM AUTHOR]

Cr3+-doped phosphors show great application prospects in near-infrared (NIR) LEDs owing to good compatibility with blue LED chips. However, current NIR phosphors still have some shortcomings in the practical application, such as narrowband emissions and low efficiency. Herein, a new Cr3+-doped Mg 3 Lu 2 Ge 3 O 12 (MLGO) broadband NIR phosphor has been successfully synthesized. X-ray diffraction and transmission electron microscopy demonstrate the sample crystallizes in the garnet structure with the Ia 3 ‾ d space group. Under 442 nm excitation, MLGO:0.04Cr3+ represents a broadband emission centered at 770 nm with a full width at half maximum of 158 nm, and has an external quantum efficiency of 12.5 %. Moreover, the emission intensity of MLGO:0.04Cr3+ at 125 °C still reaches 50 % of that at room temperature. Additionally, a NIR LED device is fabricated by combining the sample with a blue LED chip, and has an excellent NIR output efficiency of 13.1 %. Under the illumination of the NIR LED, clear images can be successfully captured in the dark. Therefore, the MLGO:Cr3+ phosphors can be used for NIR light sources applied in the areas of food analysis and night vision imaging. [ABSTRACT FROM AUTHOR]

With increased resistant pests and lowcrop yields, farmers especially in sub-Saharan Africa have greatly embraced usage of chemicals. These chemicals include pesticides used in gardens for better yields and also in the stalls for longer shelf life by sellers of farmproducts especially fresh perishables like tomatoes, cabbages, carrots, and green pepper vegetables. This, if not checked, may expose humans and animals to pesticide residues. In this research, a model for detecting the presence of pesticide residues in edible parts of vegetables (tomatoes, cabbages, carrots, and green pepper) was developed. A dataset consisting of 1094 images of both contaminated and uncontaminated vegetables including tomatoes, cabbages, carrots, and green pepper with a scale magnification of 800 × 1276 pixels taken using InfiRay P2 pro Night Vision Go Mini Infrared Thermal camerawith a thermalmodulewas taken fromdifferent dailymarkets inMbarara city, South WesternUganda. Image preprocessingwas done by noise removal and grayscale conversion. Both the neural network and median filter were applied on the images. A python scriptwas used to cluster the dataset based on chemical concentrations rates of 0.1-0.8 mg/kg, 0.9-1.3 mg/kg, and 1.4-1.7 mg/kg, and this was done for both training and testing dataset. Feature extraction was done to detect the presence of mancozeb, dioxacarb, and methidathion residues from the cleaned images. To test the developed model, convolutional neural networks transfer learning models, Inception V3, VGG16, VGG19, ResNet50, and the scratch model were used. From the results obtained, Inception V3 achieved better performance compared to other transfer learning models with 96.77% followed by VGG16 at 86.98%, VGG19 at 87.56%, and ResNet50 at 82.11%, whereas the developed scratch model achieved 89.13% classification accuracy. [ABSTRACT FROM AUTHOR]

In the autonomous driving industry, there is a growing trend to employ long-wave infrared (LWIR)-based uncooled thermal-imaging cameras, capable of robustly collecting data even in extreme environments. Consequently, both industry and academia are actively researching contrast-enhancement techniques to improve the quality of LWIR-based thermal-imaging cameras. However, most research results only showcase experimental outcomes using mass-produced products that already incorporate contrast-enhancement techniques. Put differently, there is a lack of experimental data on contrast enhancement post-non-uniformity (NUC) and temperature compensation (TC) processes, which generate the images seen in the final products. To bridge this gap, we propose a histogram equalization (HE)-based contrast enhancement method that incorporates a region-based clipping technique. Furthermore, we present experimental results on the images obtained after applying NUC and TC processes. We simultaneously conducted visual and qualitative performance evaluations on images acquired after NUC and TC processes. In the visual evaluation, it was confirmed that the proposed method improves image clarity and contrast ratio compared to conventional HE-based methods, even in challenging driving scenarios such as tunnels. In the qualitative evaluation, the proposed method demonstrated upper-middle-class rankings in both image quality and processing speed metrics. Therefore, our proposed method proves to be effective for the essential contrast enhancement process in LWIR-based uncooled thermal-imaging cameras intended for autonomous driving platforms. [ABSTRACT FROM AUTHOR]