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Forensic document examination has been considered one of the most important fields in the forensic science. For this, a quick, effective, and cheap techniques for evaluation of forensic evidence is highly required. This study explores the comparison of A4 document paper by chemical and physical analysis. 16 of white A4 paper from different brands were analyzed by FTIR for investigation of structural characteristics. Video Spectral Comparator 8000 has been used to compare the A4 papers under different light source. The inorganic filler composition in the paper is also explored by ICP‐OES. The calcium carbonate content in document papers play a discriminant role which found to be between 16.02 % and 35.54 %. Also, water contact angle has been utilized in order to examine the surface of paper which is generally related to the inorganic filler and other additives. The WCA results ranged between 83° and 111° that enable quick and easy way to compare A4 document papers. The experimental results have demonstrated that besides FTIR methods, other methods such as ICP‐OES for elemental composition, WCA for wetting test, VSC for visualization under different light of source could have been applied for comparison of document papers in case of criminal cases. [ABSTRACT FROM AUTHOR]

Photoreversible color‐switching materials, which can reversibly change color in response to external light stimuli, have attracted increasing attention for their applications in time‐sensitive information storage and optical data storage fields. But most of the related materials are dyes or redox compounds with ultraviolet as the light source, dramatically limiting the cycling stability during discoloration processes. To address this problem, a near‐infrared (NIR)‐responsive rewritable paper via doping layered Co‐metal–organic frameworks (MOFs) into the stable polyvinylidene fluoride matrix is reported for the first time. Layered Co‐MOF shows a rapid color‐switching characteristic between orange and black blue upon NIR illumination on/off because of the interlayer spacing changes. Benefiting from the soft network structures of the matrix, Co‐MOF can be homogeneously distributed to deliver an outstanding reversibility performance, including rapid response, coloration in a short period, and decoloration within about 3 min in ambient air. The fabrication of new photoreversible color switching system holds great potential in communication security, which offers a viable pathway to achieve ink‐free photoreversible printing. [ABSTRACT FROM AUTHOR]

Compared with traditional paper relying on cellulose, the polymeric paper written by light can satisfy more multi‐environmental stability and reusability for sustainable development. Herein, proposed for the first time, a novel multifunctional polymeric paper with a patch‐sewing structure is designed, presenting the reversible writing/re‐writing performance. Meanwhile, a series of Fe‐based oxides with various submicron structures inherited from metal–organic framework templates are reported, in which the optimum one exhibited 95.04% absorbance from the finite difference time domain simulation and realized photothermal conversion instantaneously (soaring to 300 °C within 38 s). Given the distinguished mechanical properties (the tensile strength of 21.34 MPa and elongation at break of 546.06%), shape‐memory ability, and multi‐environmental stability, the composites are perfect for information recording. Due to the addition of the liquid crystal phase serving as the ink on the paper, the stress concentration and destruction can be recorded on the surface while it can recover to the initial situation by near‐infrared irradiation. Moreover, the remote writing with precision triggered by a focused light source can be achieved in multiple situations (air, water, and ice), which paved the way for the next generation of paper, especially in extreme conditions like deep‐water or aerospace. [ABSTRACT FROM AUTHOR]

The aim of this study is to examine the role of different formulations of calcium carbonates on the inkjet printing quality, with the use of cationic carboxymethyl cellulose (CMC)‐starch as a binder in the formation of the coating structure of paper to use for inkjet printing. For this, GCC (ground calcium carbonate), PCC (precipitated calcium carbonate) and ECC (eggshell calcium carbonate), which have been tried as new coating materials in recent years, are mixed in different proportions to form a different coated formulation and plastered on the newly produced paper surface. Then, optical and physical tests of the obtained samples are carried out. Then, printing properties of the papers on which drop‐on‐demand system inkjet printing is made are examined. According to the obtained data, it is determined that the optical properties of coated paper with GCC + PCC blends outperformed papers coated with other blends. According to the physical test results, GCC + PCC blended coated papers showed the best performance in breaking length and tear indices. ECC + PCC blended coated papers however showed the best performance in burst indices. It is determined that as the particle size of the calcium carbonates in the coating materials decreased, the burst indices value also decreased. This situation is the opposite for breaking length and tear indices values. When the inkjet printing features are examined, it is seen that the best results are obtained from GCC + ECC coated papers in general. The most optimal metamerism indices results, measured under three different light sources, are obtained on GCC + PCC coated papers. [ABSTRACT FROM AUTHOR]

Cholesteric liquid crystal (ChLC) is a reflective display technology that utilizes ambient light sources to display images, eliminating the need for a backlight. With its bistable characteristics, ChLC displays only require voltage supply during screen updates, resulting in significant energy savings. To cater to various application scenarios, we have developed ChLC reflective displays with different functionalities and sizes. The 7.9‐ inch passive matrix ChLC reflective display offers features such as full‐color capability, wide viewing angles, and fast refreshing rate, making it suitable for electronic book applications. The 24.5‐ inch and 13.3‐inch displays are respectively the largest passive matrix ChLC reflective display and active matrix ChLC reflective display in the world. They incorporate wide temperature range materials and high contrast ratio driving methods, making them highly suitable for outdoor public information display applications. [ABSTRACT FROM AUTHOR]

This document discusses the optimization of display systems for augmented reality glasses. The author categorizes augmented reality devices into three groups based on field of view (FOV): small FOV (15-30 degrees), medium FOV (~50 degrees), and large FOV (>65 degrees). The author explores different choices and consequences for projectors, combiners, and dimmers in each category. They also discuss the use of different technologies, such as microLED panels, LCoS, OLED, and laser beam scanning. The document emphasizes the importance of optimizing the overall system, including illumination, projectors, displays, and waveguides, to achieve desired performance metrics such as resolution, efficiency, contrast, brightness, volume, and weight. [Extracted from the article]

Expansion of devices to access the virtual world is expected due to much attention to Metaverse in recent years. In particular, head mount display (HMD), smart glasses and AR glasses have been attracting attention as next‐generation mobile devices that will replace smart phones. Laser diodes and μLEDs are developed in various research institutes and companies as light sources for those devices. In this paper, we describe the development status of the laser diodes and the μLEDs, the technical problems of optimal adaptation to smart glasses, and introduce one of the solutions when using the laser diodes. [ABSTRACT FROM AUTHOR]

The latest achievements of GaN‐based laser diodes are summarized, focused on two topics: watt‐class high‐power edge‐emitting lasers and milliwatt‐class vertical‐cavity surface‐emitting lasers. These light sources have high efficiency and high reliability, which are suitable for various display applications such as laser projectors and/or ARIVR displays. [ABSTRACT FROM AUTHOR]

Solid state light sources for projection displays have shown tremendous progress over the recent years. Their application usage is ranging from low luminance near to eye projection for augmented reality glasses to mainstream projectors. This presentation will share some of the latest progresses for laser and LEDs for Near‐to‐eye (NTE) displays and will describe important design challenges such as package integration and power efficiency. Besides, High Current LEDs are further pushing the limits and bring LED based projection light engines on eye‐to‐eye brightness level with lamp & laser‐based systems ranging up to 5,000 ANSI lumens. [ABSTRACT FROM AUTHOR]

In recent years, Laser Diodes have been used in various applications. The first real application started with the release of compact disc(CD) players/digital versatile disks (DVD) players. Since blue and green lasers have been developed, and laser diodes have begun to be used for various display applications such as pico‐projector and Laser TV. In particular, recently, it is expected to be applied to head mount display(HMD) and Augmented reality(AR)/virtual reality(VR) glass applications as one of the new applications of single mode laser. This paper shows the laser diode and applications that have been developed so far, the trends of light sources for HMD and AR/VR glass applications that are expected in the future, the issues when using red green and blue laser diodes, and how to solve them. [ABSTRACT FROM AUTHOR]

The AlGaInP red laser diodes were developed at the end of the 1980s, and since then we have been improving performance of laser diodes. Along with the improvement of laser performance, laser diodes has been used various applications such as optical discs and sensors. Recently, research and practical use of display applications and AR / VR devices are remarkable. In this paper, we mainly report on red laser diodes developed for display applications. [ABSTRACT FROM AUTHOR]

The annulus light source method separates specular and diffuse components of reflected glare from display surfaces. Combining it with the variable aperture source method delivers source‐size dependence. Measuring diagnostic reflection samples and ePaper with mirror‐like or scattering surfaces confirmed that the source‐size dependence of reflected glare comes from haze scatter. [ABSTRACT FROM AUTHOR]

People's interest in health care has increased these days. As various health care platforms are emerging, the corresponding market is also expanding. In order to monitor health conditions in everyday life, no physical damage should be made. One of the non‐invasive method, using light for sensing, is preferred due to this effect. In general, as the wavelength increases, light can penetrate deeper into the skin, leading to different bio‐signals. For example, All‐in‐One Sensor Display, which was announced by Samsung Display at SID 2023, used green light to selectively sense fingerprints on the skin surface by reducing the depth of skin penetration. To apply this progress to health care, red light can also be used for OPDs in the All‐in‐One Sensor Display. In this case, red light from red pixel is used as the light source. The light can reach blood vessels under the epidermis because the skin penetration depth is deeper than green light. The light reaching the blood vessel becomes a signal to gather biometric information. This biometric information is then collected at OPD as the signal reaches the OPD in the panel again. For these series of processes, an OPD capable of effective detecting of light in the 625 nm region emitted by red pixels is required. In this study, OPD was fabricated using RD‐01, a high absorption donor material suitable for red light absorption, and RA‐01, a non‐fullerene acceptor for mass production, to respond to red light near 625 nm. The EQE of the OPD was 25% at wavelength of 625 nm. In addition, absorption spectrum of the OPD covers the Red emission effectively. Our results represent that OLED panel can be used for not only fingerprint recognition but also health care platform. [ABSTRACT FROM AUTHOR]

In order to solve the problem of lack of detail information and serious damage to the texture of the light source area when the dark channel prior dehazing algorithm processes fog images at night, this paper proposes a dehazing algorithm for nighttime fog images using the dark‐state point light source model. By introducing the dark state point light source model, the dark channel credibility weight factor and the pseudo dehazing image, combined with the nighttime image imaging model, the improved transmittance distribution is obtained, and the fog image at night is dehazed. The experimental results show that the image processed by the algorithm in this paper has little loss of texture details, high image definition, and the contrast between the light and dark of the image is better stretched, which can effectively dehaze the fog image at night. [ABSTRACT FROM AUTHOR]

Light is a popular choice as an indoor energy source for Internet of Things (IoT) end devices. However, indoor light sources are intermittent, which can disrupt the operation of IoT end devices, potentially leading to safety concerns or inaccurate data. Therefore, there is a growing need to develop a long‐duration power supply for IoT end devices. The energy from ambient light is harnessed to charge a supercapacitor through an energy manager chip. This supercapacitor serves as the power source for IoT nodes when the ambient light is unavailable. Nevertheless, as the voltage of the supercapacitor drops below the operating threshold, the IoT end node will eventually shut down. This paper proposes a circuit that utilizes a Joule Thief circuit, booster converter, and capacitor stack‐up circuit to extract the remaining energy from the supercapacitor and boost the voltage, thereby extending the operational lifespan of IoT end nodes. Additionally, capacitor stack‐up circuits significantly enhance charging efficiency. PSpice design and simulations confirm circuit feasibility. High‐efficiency charging and long‐duration IoT nodes suggest replacing traditional batteries with supercapacitors, reducing environmental impact. [ABSTRACT FROM AUTHOR]

The backlight module is a key component for providing a light source for a Liquid Crystal Display (LCD), and its thickness has a direct impact on the thickness of the display. In order to reduce the thickness of the display product, it can be realized by reducing the thickness of the backlight module. In order to solve this problem, this paper proposes a design method for the microstructure of the optical film applied to the mini LED backlight module. The microstructured optical film designed in this paper can effectively improve the uniformity of brightness and realize the ultra‐thinning of the backlight module. Based on the principle of total reflection, the optical film microstructure is designed for the miniLED Lambertian light source. Under the assumption that the point light source is established, the extended light source is discretized into point light sources, and then the light energy that can be used for circulation is calculated for each point light source, and all point light sources The cyclic energy of is accumulated as the cyclic energy corresponding to the extended light source, and when its value is the largest, the best shape of the microstructure is obtained. The simulation results show that after adding the microstructured optical film, the illumination uniformity of the backlight module reaches 91.2%, which meets the uniformity requirements of the backlight module. The method of designing microstructured optical film proposed in this paper can effectively realize the ultra‐thinness of the backlight module and has strong practicability. [ABSTRACT FROM AUTHOR]

In recent years, China's advanced light sources have entered a period of rapid construction and development. As modern X-ray detectors and data acquisition technologies advance, these facilities are expected to generate massive volumes of data annually, presenting significant challenges in data management and utilization. These challenges encompass data storage, metadata handling, data transfer and user data access. In response, the Data Organization Management Access Software (DOMAS) has been designed as a framework to address these issues. DOMAS encapsulates four fundamental modules of data management software, including metadata catalogue, metadata acquisition, data transfer and data service. For light source facilities, building a data management system only requires parameter configuration and minimal code development within DOMAS. This paper firstly discusses the development of advanced light sources in China and the associated demands and challenges in data management, prompting a reconsideration of data management software framework design. It then outlines the architecture of the framework, detailing its components and functions. Lastly, it highlights the application progress and effectiveness of DOMAS when deployed for the High Energy Photon Source (HEPS) and Beijing Synchrotron Radiation Facility (BSRF). [ABSTRACT FROM AUTHOR]

A backlight module is a key component of a liquid crystal display(LCD). The thickness of the backlight module affects the thickness of the display. In this paper, a design method based on the segment‐weighted is proposed for the miniLED backlight, which could reduce the thickness of the backlight module while ensuring uniformity of luminance. A surface microstructure is designed by discretizing the extended light source into a point source and designing the corresponding point microstructure using the point source based design method and the segment‐weighted method. The simulation results show that the brightness uniformity is 70%. To further improve the brightness uniformity, a diffusion film is added with the optical distance(OD) of 0.8mm, and the brightness uniformity is improved to 88%. The optical film designed in this paper can effectively improve the brightness uniformity and realize the ultra‐thin performance of the backlight. [ABSTRACT FROM AUTHOR]

Photoplethysmography (PPG) technology enables the measurement of multiple physiological and psychological parameters with low‐cost wearable sensors and is reshaping modern healthcare. Advanced materials play a vital role in improving reliability and accuracy of PPG sensors. Recently, various advanced materials have been explored to optimize PPG sensor design, while some challenges exist toward large‐scale validation and mass production. This paper focuses on advanced materials applied in the photodetectors, light sources, and circuits of PPG sensors. The materials are categorized into four groups: inorganic, organic, nanomaterials, and hybrid materials. The properties and fabrication processes are summarized. Other technical details including the mode of operation, measurement sites, testing, and validation are discussed. The merits and limitations of the state of the art are highlighted to provide some suggestions for the future development of PPG sensors based on advanced materials. [ABSTRACT FROM AUTHOR]

Reflective liquid crystal display has the advantages of energy saving and environmental protection. When the ambient light is low, the front light source is required to provide illumination rays. The front light guide plate has a great influence on display luminance, contrast, etc. Based on Comprehensive considerations on luminance, uniformity, stray light, an analysis and evaluation method for front light guide source is proposed. Taking spherical dots as an example, the influence of dot radius and height on the comprehensive performance of the front light source is analyzed. The simulation results show that when the R:H is 3:1, the comprehensive evaluation parameters of the spherical structure are high, and the signal‐to‐noise ratio is increased by 240%, which can greatly improve the display performance. The analysis and evaluation method proposed in this paper can effectively guide the development of front light guide plates, shorten the development time and reduce the development cost. [ABSTRACT FROM AUTHOR]

Recently, a novel approach has been proposed to produce ultrashort, fully coherent high-repetition-rate EUVand X-ray radiation by combining an energy recovery linac (ERL) with the angular-dispersion-induced microbunching methodology. It is critical to maintain microbunching when the beam passes through bending magnets between the undulators, which results in difficulties supporting multiple beamlines. In this paper, the design of a multiplexed emitting system consisting of multi-bend achromats, matching sections and radiators to facilitate the multi-beamline operation is presented. Theoretical analysis and numerical simulations have been carried out and the results show that the microbunching and beam quality can be well maintained after four times of bending. Five radiation pulses with a central wavelength of 13.5 nm and peak power at theMW level have been produced by the same electron beam via this multiplexed emitting system. The proposed method holds potential in the multi-beamline operation of ERL- or storage-ring-based coherent light sources. [ABSTRACT FROM AUTHOR]

Double-crystal monochromators (DCMs) are one of the most critical optical devices in beamlines at synchrotron sources, directly affecting the quality of the beam energy and position. As the performance of synchrotron light sources continues to improve, higher demands are placed on the stability of DCMs. This paper proposes a novel adaptive vibration control method combining variational modal decomposition (VMD) and filter-x normalized least mean squares (FxNLMS), ensuring DCM stability under random engineering disturbance. Firstly, the sample entropy of the vibration signal is selected as the fitness function, and the number of modal components k and the penalty factor x are optimized by a genetic algorithm. Subsequently, the vibration signal is decomposed into band frequencies that do not overlap with each other. Eventually, each band signal is individually governed by the FxNLMS controller. Numerical results have demonstrated that the proposed adaptive vibration control method has high convergence accuracy and excellent vibration suppression performance. Furthermore, the effectiveness of the vibration control method has been verified with actual measured vibration signals of the DCM. [ABSTRACT FROM AUTHOR]

Single-crystal chemical vapour deposition (CVD) diamond detectors are an established transmissive synchrotron beamline diagnostic instrument used for beam position and beam intensity monitoring. A recently commercialized alternative is silicon carbide (4H-SiC) devices. These have the potential to provide the same diagnostic information as commercially available single-crystal CVD diamond X-ray beam position monitors, but with a much larger transmissive aperture. At Diamond Light Source an experimental comparison of the performance of single-crystal CVD diamond and 4H-SiC X-ray beam position monitors has been carried out. A quantitative comparison of their performance is presented in this paper. The single-crystal diamond and 4H-SiC beam position monitors were installed in-line along the synchrotron X-ray beam path enabling synchronous measurements at kilohertz rates of the beam motion from both devices. The results of several tests of the two position monitors' performance are presented: comparing signal uniformity across the surface of the detectors, comparing kHz intensity measurements, and comparing kHz beam position measurements from the detectors. Each test is performed with a range of applied external bias voltages. A discussion of the benefits and limitations of 4H-SiC and single-crystal CVD diamond detectors is included. [ABSTRACT FROM AUTHOR]

The objective is to improve the recognition rate of white and near cotton‐coloured impurities in raw cotton against a single white visible light source background. A lightweight detection network model without anchor boxes based on improved YOLO v4‐tiny is proposed in this paper based on weighted feature fusion (WFF). The WFF strategy was used to improve the detection accuracy of the improved YOLO v4‐tiny algorithm. Meanwhile, to address the disadvantage that the anchor boxes obtained by the K‐means algorithm clustering do not have global features, the anchor‐free and tiny decoupled head schemes are used instead of the traditional coupled detection head. The improved algorithm was validated on the PASCAL VOC2012 dataset and the self‐built raw cotton impurity dataset collected by high‐speed camera. On the raw cotton impurity test set, compared to the original YOLO v4‐tiny model, the mean average precision (mAP) and frames per second (FPS) of the improved model increased by 10.35% and 6.9%, respectively. The proposed model detects white and near cotton‐coloured impurities with an accuracy of up to 98.78% and 98.00%. The experimental results show that the proposed method can effectively detect and identify impurities in raw cotton, which is of great practical significance for foreign matter detection and identification in cotton. [ABSTRACT FROM AUTHOR]

GLO:O8T/01dec21:jrs6102-fig-0001.jpg PHOTO (COLOR): 1 Photomontage (courtesy of David Long and the family): From the bottom left, proceeding anticlockwise: Derek Long at the start of his scientific career, as a member of Jesus College matriculating into the University of Oxford in 1943, his first book "Raman Spectroscopy", his last book "At the Sign of Atlas: the Life and Work of Joseph Moxon, A Restoration Polymath", his cottage "Three Houses" at Llandeloy, Roch, Dyfed where much of his writing was undertaken, his collection of classic woodworking planes (including a facsimile of the ivory Roman plane excavated at Goodmanham, which was the topic of his last paper published in JRS with Howell Edwards), and finally, Derek in his garden with his dog, Rupert gl This appreciation covers the 25 years from 1995 to the present and follows on from the survey of the predominantly spectroscopic career of Derek Long that was presented in a special issue of JRS in August 1995, on the occasion of his reaching his 70th birthday that year. That same year, he collaborated in what is believed to be his last scientific research paper in Raman spectroscopy, published in JRS that same year with the author, on the Raman spectroscopic analysis of the Goodmanham plane. It is noteworthy that this last paper of his in his beloved JRS brought together his diverse interests in classic woodworking tools, antiquarianism and in Raman spectroscopic analysis. [Extracted from the article]

Light detection and ranging (LiDAR) sensor is widely recognized as a critical component for accurate perception. However, there are a host of challenges that impede their performance, including low spatial resolution, high costs, large size, low reliability, and susceptibility to interference. It is challenging to overcome these issues using a single LiDAR module, necessitating the need for a review of current LiDAR technologies. The paper commences by introducing the fundamental principles of various laser rangefinders and discussing the optical modulation technologies used to prevent interference and ghost images. Next, the paper delves into the latest developments in laser technology, with a focus on enhancing the switching rate, compliance with eye safety regulations, miniaturization, and improving stability. One highly promising innovation is the photonic crystal surface emitting laser (PCSEL), a novel light source that boasts high‐speed, small divergence angles, and high‐power output. Finally, the paper discusses the advancements made in non‐solid‐state scanning and solid‐state scanning, such as improving stability, increasing scanning angles, and optimizing the manufacturing of mechanical and micro‐electromechanical systems (MEMS). Additionally, the paper highlights the recent advancements in nanotechnology, specifically metasurface technology, which offers superior capabilities such as beam deflection, enhanced field‐of‐view (FOV), and dynamic modulation. [ABSTRACT FROM AUTHOR]

Mask plays major role in the photolithography process during whole TFT manufacturing. The photolithography process transfers the desired pattern on mask into panel substrate, which forms some portions of device and performs some electric or optical functions. Due to pattern continuously duplicated, a correct pattern shape of mask is very important in the photolithography process. An abnormal pattern will results in huge loss of yield and cost. The haze, a foreign matter grown or deposited on the surface of mask, is already a prevalent phenomenon in TFT photolithography manufacturing or well known in semiconductor manufacturing. It is already well identified that it is highly related to the storage environment of mask, that is, the so called AMC (Airborne Molecular Contamination). A summarized mask haze classification based on past industrial service experience is proposed and a case study result with haze sampling at the site of mask manufacturer is followed in this review to show the understanding of the recently state of the art about mask haze in TFT industry. With the development of industrial technology, the clean room area of TFT panel and semiconductor plant construction project is getting larger and larger (a single clean area of 100,000 square meters), and the investment cost is getting higher and higher. The owners have higher and higher requirements on the cost control and intelligence of the project, including plant construction cost, operating cost and energy saving, which have been highly concerned by the owners. In the actual execution of TFT panels and semiconductor projects, owners often hear the problems about clean room lighting system, which are summarized as follows: The illumination required by the process is 400lux, and the initial design is 600lux. By artificially opening the number of lamps, the attenuation problem of the light source for a long time in the later period is compensated. The owner needs to close several circuits of lamps in the early stage to meet the illuminance requirements of the clean room. If the lamps and lanterns are not closed in the early stage, part of the operation cost and energy waste will be caused;With the passage of time, the illumination of clean room will also decrease with time, and when to what illumination should be opened several circuit lamps, in order to meet the needs of clean room process? But also not waste energy and so on;With the operation of the plant, when can the illumination of the clean room lamps and lanterns not meet the requirements of the process when they are all opened? And when do light fixtures need to be replaced?Part of the lamps are broken. Whether the illuminance of the clean room in this area is much lux, and whether it meets the illuminance demand of the process, etc.;In the illuminance test when the project is completed and handed over to the owner, it is usually done by outsourcing or management personnel at different points to measure manually on the spot, which consumes time and labor cost, and if the instrument measurement is wrong, the amount of newly measured works is relatively huge, etc.When do clean room lamps need to be replaced? The owner will normally deal with the above problems: If more experienced owners turn on or off the number of lamps and lanterns based on their experience, there are also risks of energy waste and insufficient illumination;All open to meet the illuminance demand, there is excessive waste of energy and operation costs;With the passage of time, light source attenuation, part of the lamps are broken, usually artificial field measurement, to confirm whether the lamps need to be replaced, time and labor costs;If the process department doubts the illuminance value of the factory department, it also needs to measure on site or find the data of the completed illuminance test before as the basis, especially the existing clean room renovation project;The measurement of completion acceptance is usually on‐site measurement or outsourcing can provide corresponding data to prove acceptance, etc.; According to the above problems, this paper describes a real‐ time online illuminance and light decline monitoring technology to deal with the actual problems of TFT panel and semiconductor. Automatic control is realized for the closing and opening of the owner's lamps through the cumulative average illuminance, etc., and the requirements of the process illuminance are met to save energy consumption and operating costs;The real‐time cumulative monitoring of the luminescence life curve of this technology is compared with the luminescence life curve provided or tested by the manufacturer, which can confirm the early warning and comparison of the deviation between the actual luminescence life and the luminescence life provided by the manufacturer, so that the owners can purchase or replace the number and area of the luminescence in advance; [ABSTRACT FROM AUTHOR]

In this paper, a new type of full attachment double‐sided liquid crystal display is designed. The liquid crystal screen and optical films are bonded by OCA called full‐ attachment LCD. The double‐sided display mentioned in this paper uses the same light source on both sides, and the light guide plate is made of glass material or nano material. The double‐sided display designed in this paper is ultra‐thin and the border is extremely narrow. It uses a full attachment optical architecture, higher utilization of light sources, and lower power consumption. Because it does not require a double‐sided backplane design, it is lighter. Its performance has been improved, and its cost has been reduced. [ABSTRACT FROM AUTHOR]

Broadband near‐infrared (NIR) phosphor converted light emitting diodes (pc‐LEDs) are novel compact light sources that enable portable devices for substance detection. However, to achieve such efficient pc‐LEDs is still a challenge due to lack of efficient phosphors. In this paper, Stokes shift as an efficiency predictor is emphasized. In Cr3+ activated Ca2LuZr2Al3O12 (CLZA) garnet phosphor, Stokes shift decreases from 2990 to 2854 cm−1 upon substituting Ca‐Zr with Lu‐Al. As a result, electron–phonon coupling related nonradiative process is reduced. The external quantum efficiency is significantly enhanced to 47.4%, and the as fabricated NIR pc‐LED offers 33.7% @10 mA electro‐optical efficiency. The results can advance the development of efficient NIR phosphors. [ABSTRACT FROM AUTHOR]

Photocatalytic oxidation is one of the main factors leading to the aging damage of Chinese traditional dyes and pigments. In this study, in order to analyze the photoaging characteristics of traditional dyes and pigments commonly used in Chinese cultural relics in different environments, we used traditional Chinese painting pigments to make colored paper samples, and used traditional dye extraction and dyeing technology to make colored silk samples. By setting up nitrogen and atmospheric chamber and using LED, tungsten halogen lamp, metal halide lamp and fluorescent lamp as light sources, an accelerated photoaging contrast test on 16 kinds of dyes and pigments was carried out, and then the color difference of different samples in different light environment and atmosphere environment was obtained. Through systematic analysis, the results show that the type of light source and the gas environment will affect the photoaging rate of the samples. The nitrogen environment can significantly reduce the degree and speed of photoaging, especially for organic dyes and pigments. [ABSTRACT FROM AUTHOR]

The field of nitride‐based materials is producing some of the most promising and interesting candidates for advanced technology applications. Novel formulations and polymorphs are of interest for applications requiring one or more of: high hardness, high oxygen resistance at elevated temperatures, catalytic action, semiconductor light sources, and (ultra‐)wide band gap electronics. The synthesis of nitrides with excellent single crystal structural quality of an appreciable size is challenging whether working in solution growth techniques like ammonothermal and flux growth, or in vapor deposition techniques. This paper presents a perspective on recent developments in equipment and techniques for single crystal nitride synthesis with a view toward progress anticipated in the next 5–10 years. [ABSTRACT FROM AUTHOR]

In recent years, with the further ministration of the semiconductor device in integrated circuits, power consumption and data transmission bandwidth have become insurmountable obstacles. As an integrated technology, photonic integrated circuits (PICs) have a promising potential in the post‐Moore era with more advantages in data processing, communication, and diversified sensing applications for their ultra‐high process speed and low power consumption. Silicon photonics is believed to be an encouraging solution to realize PICs because of the mature CMOS process. The past decades have witnessed a huge growth in silicon PICs. However, there is still a demand for the development of silicon PICs to enable powerful chip‐scale systems and new functionalities. In this paper, a review of the photonic components, functional blocks, and emerging applications for PICs is offered. The common photonic components are classified into several sections, including on‐chip light sources, fiber‐to‐chip couplers, photonic resonators, waveguide‐based sensors, on‐chip photodetectors, and modulators. The functional blocks of the PICs mentioned in this review are photonic memories and photonic neural networks. Finally, the paper concludes with emerging applications for further study. [ABSTRACT FROM AUTHOR]

Developing self‐oscillating soft actuators that enable autonomous, continuous, and directional locomotion is significant in biomimetic soft robotics fields, but remains great challenging. Here, an untethered soft photoactuators based on covalently‐bridged black phosphorus‐carbon nanotubes heterostructure with self‐oscillation and phototactic locomotion under constant light irradiation is designed. Owing to the good photothermal effect of black phosphorus heterostructure and thermal deformation of the actuator components, the new actuator assembled by heterostructured black phosphorus, polymer and paper produces light‐driven reversible deformation with fast and large response. By using this actuator as mechanical power and designing a robot configuration with self‐feedback loop to generate self‐oscillation, an inchworm‐like actuator that can crawl autonomously towards the light source is constructed. Moreover, due to the anisotropy and tailorability of the actuator, an artificial crab robot that can simulate the sideways locomotion of crabs and simultaneously change color under light irradiation is also realized. [ABSTRACT FROM AUTHOR]

This article is a highlight of the paper by Choe et al. in this issue of Photochemistry and Photobiology. In that review paper, the disinfection and biomodulation outcomes promoted by antimicrobial photodynamic therapy (aPDT) on peri‐implantitis infection were stated and discussed. The killing of the oral pathogens by aPDT is based on the generation of reactive oxygen species (ROS). Besides that, biomodulation can also be provided by aPDT and improve the healing and modulate the inflammatory process. Although aPDT has shown positive effects on the treatment of peri‐implantitis disease mainly as a complimentary technique, the authors suggested that more and standardize clinical studies are needed to support the clinical application of aPDT for that purpose. Also, the standardization of parameters related to the light source and photosensitizers is required. In addition, nano‐based materials may improve aPDT performance against oral biofilms and could increase the hopes of overcoming dental implant failures. [ABSTRACT FROM AUTHOR]

Research infrastructures are commonly used by scientific and industrial communities to conduct research and experiments which translate in the creation of new knowledge. This knowledge may generate different outcomes (e.g., publications, patents) and find applications in different sectors and domains, ultimately triggering innovation developments. However, the pathway from knowledge creation to innovation is complex: it is split among different players, from the scientific community to industrial actors (even those not directly involved in the experiments) and may take time and significant investments. The objective of this paper is to assess innovation impacts arising from a Research Infrastructure and specifically tracing and describing the pathways according to which these impacts may materialize. The example used is the ALBA Synchrotron Light source facility located in Barcelona and in operation since 2012. The paper builds on the evidence collected through two surveys to direct and indirect users of ALBA (overall 384 questionnaires collected), in‐depth interviews as well as an analysis of patents' citations. It draws from a pilot exercise carried out in the framework of the Horizon 2020 Ri‐Paths project. It contributes to the broader discussion on the socio‐economic impact assessment of Research Infrastructures and relevant methodologies and metrics. [ABSTRACT FROM AUTHOR]

Machine learning has recently been applied and deployed at several light source facilities in the domain of accelerator physics. Here, an approach based on machine learning to produce a fast-executing model is introduced that predicts the polarization and energy of the radiated light produced at an insertion device. This paper demonstrates how a machine learning model can be trained on simulated data and later calibrated to a smaller, limited measured data set, a technique referred to as transfer learning. This result will enable users to efficiently determine the insertion device settings for achieving arbitrary beam characteristics. [ABSTRACT FROM AUTHOR]

With the development of display technology, several new displays have attracted much attention such as OLED display, QLED display, Laser display and Mini/MicroLED display. Displays with high brightness, wide color gamut, high efficiency and long lifetime are our ultimate goal. Defect inspections and color measurements are important for us to evaluate display quality. To obtain wide color gamut, we usually use narrow spectral bandwidth light source. However, it's not easy for traditional color camera or filter camera to measure narrow bandwidth light source because the accuracy is limited. In this paper, we simulate color measurement accuracy by color camera and filter camera. We analyze the influence of bandwidth effect on the color measurement and carry out bandwidth effect correction method. With the correction, the measurement accuracy improves obviously. In addition, different displays with different spectral bandwidth have been measured to validate the corrections. The results show significant improvement in color measurement accuracy. Our bandwidth effect correction can be used for wide color gamut display measurement. [ABSTRACT FROM AUTHOR]

In this paper, we present a novel approach for real‐time rendering of soft eclipse shadows cast by spherical, atmosphereless bodies. While this problem may seem simple at first, it is complicated by several factors. First, the extreme scale differences and huge mutual distances of the involved celestial bodies cause rendering artifacts in practice. Second, the surface of the Sun does not emit light evenly in all directions (an effect which is known as limb darkening). This makes it impossible to model the Sun as a uniform spherical light source. Finally, our intended applications include real‐time rendering of solar eclipses in virtual reality, which require very high frame rates. As a solution to these problems, we precompute the amount of shadowing into an eclipse shadow map, which is parametrized so that it is independent of the position and size of the occluder. Hence, a single shadow map can be used for all spherical occluders in the Solar System. We assess the errors introduced by various simplifications and compare multiple approaches in terms of performance and precision. Last but not least, we compare our approaches to the state‐of‐the‐art and to reference images. The implementation has been published under the MIT license. [ABSTRACT FROM AUTHOR]

This paper describes how moiré plasmonic nanoparticle lattices can exhibit lasing action over a broad wavelength and wavevector range. Moiré nanolithography is combined with the PEEL (Photolithography, Etching, Electron‐beam deposition, and Lift‐off) process to fabricate in‐plane incommensurate lattices with optical properties beyond the restricted geometries of Bravais lattices. Because of increased rotational symmetry, moiré lattices support a larger number of transverse electric and transverse magnetic modes relative to their periodic base lattices. It is found that multidirectional lasing characteristics can be predicted by the symmetry of the moiré reciprocal lattice. Incommensurate moiré plasmonic lattices combine advantages of the dense band structures observed in aperiodic lattices with that of predicted modes in Bravais lattices for light‐based technologies in coherent light sources and multiplexed data transfer. [ABSTRACT FROM AUTHOR]

Cr3+‐activated broadband near‐infrared (NIR) phosphors are studied extensively for application in phosphor converted light‐emitting diode (pc‐LED), a new light source for substance testing based on NIR spectroscopy. However, the emission of Cr3+ is mainly located in the NIR I region (700–1000 nm) and many substances show the characteristic spectroscopy in the NIR II region (1000–1700 nm). In this paper, dual‐wavelength emission of NIR I and NIR II is realized in Cr3+ and Ni2+ codoped Zn3Ga2GeO8 (ZGGO) via energy transfer from NIR I emitting Cr3+ to NIR II emitting Ni2+. The photoluminescent properties of the doped ZGGO are studied as a function of doping concentration and the optimal concentrations of Cr3+ and Ni2+ are determined to be 0.04 and 0.003, respectively, with internal quantum efficiency (IQE) of 37.5%. The ZGGO:Cr3+, Ni2+ phosphor‐in‐glass (PiG), is prepared for fabricating PiG‐converted ultrabroadband NIR LEDs to avoid serious reabsorption of the NIR II emission as in the pc‐LED packaged using phosphor dispersed epoxy resin or silicone. The PiG pc‐LED offers photoelectric efficiency of 4.3%@20 mA and NIR output power of 17 mW@200 mA and shows stable spectral distribution against drive current compared to pc‐LED. [ABSTRACT FROM AUTHOR]

Accurate whiteness measurement is critical across various industries including textiles, paper, and detergents. With the advent of fluorescent whitening agents (FWAs), the assessment of whiteness has evolved from simply measuring reflectance to determining the spectral radiance factor (SRF) of materials. While multispectral imaging (MSI) can effectively measure object reflectance and colour, its accuracy is compromised by FWAs that significantly augment spectral reflectance. Thus, reliable whiteness measurement requires the determination of both reflectance and SRF. This article presents the design of a specialised light source equipped with an ultraviolet (UV) filter to provide adjustable illumination within an integrating sphere system. By tuning the position of the UV filter, multispectral images are captured of a fabric under varying UV exposures. These images are subsequently processed and combined to reconstruct full‐range visible spectrum information. This approach is shown to achieve high accuracy and spatial uniformity in quantifying the whiteness of textiles using MSI. [ABSTRACT FROM AUTHOR]

Analog documents and scanned digitized files are now considered equivalent in legal contexts, and the widespread supply of multi‐functional printers has led to a surge in the use of scanned documents. With image editing tools, there has been more cases of forgery involving scanned files. This has highlighted the importance of integrity and authenticity verification of scanned documents submitted as court evidence. Extensive studies have been conducted on source scanner identification and detection of alteration in scanned documents. Past research usually relied on machine learning with Support Vector Machine (SVM) and Convolutional Neural Network (CNN), and was focused more on images rather than text documents. Brightness variations are produced depending on the repetitive arrangement and relative intensity of light sources, and such patterns can be clearly observed in scanned images by the Charged Coupled Device (CCD) type flatbed scanner. The separate image module of the Contact Image Sensor (CIS) also leads to characteristic brightness variations. To extract and enhance these brightness variations, image processing techniques such as separating color channel and adjusting gradation and contrast are applied. The proposed method was tested on five scanner models, and the results confirmed that each scanner had unique brightness variations. This study is the first to extract brightness variations as a unique characteristic of each scanner model and recognize the potential of brightness variations in source identification and manipulation detection. A major advantage is that brightness variations are physical, robust, and visible. The research will be expanded with multicolor documents, counterfeit documents, and text‐independent detection. [ABSTRACT FROM AUTHOR]

The shape recovery quality of photometric stereo is sensitive to complicated error factors under close range lighting of quasi‐point lights. However, the error performance of photometric stereo under this practical scenario is still obscure. This paper presents a comprehensive error analysis of photometric stereo with near quasi‐point lights (NQPL‐PS). Five main error factors are identified under this scenario and their corresponding analytical formulations are introduced. Statistic computation and experiments are used to validate the theoretical formulations and inspect the relationships between normal inaccuracies and each type of discrepancies. In addition, the impacts of multiple system parameters of an NQPL‐PS configuration on the normal estimation error are also studied. In order to evaluate the relative importance of various error factors, a probability‐based evaluation criterion is proposed, which focuses on the error performance over the state space and the error space, rather than the simple comparison of the values of normal inaccuracy. The assessment results show that the non‐uniformity of illuminants, and the calibration error in the position of light sources hold the dominant places among those five error factors. This paper provides insights for the accuracy improvement and system design of NQPL‐PS. [ABSTRACT FROM AUTHOR]

Pico‐projection displays are the main developing direction for future projection displays, but the balance between the optical efficiency and the system size is still a big concern. This paper presents a pico‐projector design based on micro‐LED (μLED) light sources. Firstly, based on the analysis of the characteristics of μLED, a highly integrated microlens array is designed to improve the system efficiency by reshaping the spatial light distribution. In addition, the matching relationship between the aperture angle of projection lens and the divergence angle of μLED is studied, and on this basis, a set of four‐piece spherical lens group is proposed to achieve compact size. Simulation results show that the μLED equipped with the microlens array can concentrate about 86% of the light energy within a dispersion angle of ±20°, thus increasing the light energy utilization by about 3.5 times and reducing the size of the pico‐projector to 30.18 mm3. The designed pico‐projector has high performance and compact size with great potential for future applications. [ABSTRACT FROM AUTHOR]

Multimode properties, based on nonlinear parametric processes, have potential research value on entanglement imaging. This paper studies the spatial and frequency multimode from dressing parametric‐amplified six‐wave mixing (PA‐SWM) process with three entangled signals. The S1 signal contains fifth‐order nonlinearity, the S2 signal contains electromagnetically induced absorption and fifth‐order nonlinearity, and the S3 signal contains Autler–Townes splitting (AT), second‐ and fifth‐order nonlinearity. The frequency multimode is attributed to dressing energy level splitting in spontaneous SWM (SSWM) process. The spatial multimode is due to frequency multimode and beam splitting via Kerr nonlinearity. In the spatial domain, it finds the optimal conditions of intensity difference squeezing (IDS) and spatial imaging along with their competitive relationship. On the one hand, the light spots with single spatial mode are contributed to the maximum IDS but not conducive to entanglement imaging; on the other hand, the light spots with multiple spatial modes are instrumental in entanglement imaging but not appropriate for the IDS. This research has potential applications in squeezed light sources for quantum metrology, and correlated imaging of spatial signals. [ABSTRACT FROM AUTHOR]

The generation of fully coherent and femtosecond time‐scale radiation pulses in the X‐ray regime is one of the most common demands of ring‐based synchrotron light source users. In this paper, a method that utilizes the recent proposed angular dispersion induced microbunching technique to convert external light from high‐harmonic generation (HHG) to coherent light at shorter wavelength is proposed. Numerical simulations using the practical parameters of a diffraction‐limited storage ring demonstrate the generation of coherent pulse trains with photon energy as high as 2 keV, pulse duration as short as ∼10 fs and high peak brightness directly from an HHG source at 13 nm. [ABSTRACT FROM AUTHOR]

In this study, the authors found that treating blood with 1 M HCl and 2% (w/v) 5‐sulfosalicylic acid (SSA) in 1% (v/v) hydrogen peroxide mixture can produce photoluminescence of blood. SSA was added as a blood fixer. The photoluminescence was induced by irradiation of a forensic light source at 505 nm, which was detected using a 550 nm barrier filter. In this experiment, various level of acid and hydrogen peroxide were tested to find the optimal formulation of reagents, spot tests were conducted with diluted blood to test the sensitivity of this reagent, and impressions in blood left on porous/nonporous surfaces were enhanced. The sensitivity of this solution was slightly lower than Bluestar and was similar to leucocrystal violet or leucomalachite green on both porous/non‐porous surfaces. The photoluminescence of blood treated with this reagent has been observed over 2 months. Using this reagent, it was possible to observe fingermarks or footwear impressions in blood on a black porous/non‐porous surface. Through this, it was found that using this reagent could enhance bloodstains regardless of the porosity or color of the surface. [ABSTRACT FROM AUTHOR]

Luminescent metal halides, as a type of luminescent semiconductor material, offer advantages that fulfill the requirements of emerging light source devices, such as high luminescence efficiency, good thermal stability, and tunable colorful emission. Blue light being one of the three primary colors plays a crucial role in the field of lighting and colorful displays. However, the progress in device performance of blue‐light materials lags behind that of green and red‐light materials. Currently, there have been numerous reports on metal halide perovskite blue‐light materials, but a comprehensive review on the development and performance control of blue‐light metal halides is yet to be found. This paper provides a comprehensive summary of the design strategies and luminescence mechanisms of blue‐light perovskites with various luminescence centers, as well as their application progress in the fields of light‐emitting diodes (LEDs), X‐ray scintillators, information anti‐counterfeiting and encryption. It also explores possible directions for subsequent performance improvement. This work aims to offer valuable insights and recommendations for the future development of blue‐light metal halides, with significant implications for the fabrication of novel blue light devices and advancements in detection technology. [ABSTRACT FROM AUTHOR]

A photosensitive TFT sensor called bias TFT fabricated using simple amorphous silicon process in this paper. The photosensitive current of bias TFT is linearly related to the brightness of the top light source and inversely proportional to the size of the bias region. The photosensitivity current can be up to 10E‐8 amperes under 100 nits illumination. Among four shapes of bias TFTs, L‐type TFTs have the highest photo current. [ABSTRACT FROM AUTHOR]

The transition from LCD to OLED and µLED as dominant lighting sources for consumer displays in smart devices and AR/VR displays poses new challenges to light measurement. OLEDs and µLEDs exhibit completely different and far greater variations in their spectral distribution, for the measurement of which calibrations with standard light sources e.g. illuminant A are not optimally suited. Metrological traceability is thus particularly important for the interpretation of display measurements using (O)LED based light sources. The paper introduces experimental data on the traceable color accuracy of consumer display measurements based on different display technologies and therefore different variations in spectral distribution. We evaluate the influence of different calibration approaches and calibration sources. We also examine and compare the influence of internal and external spectral reference approaches on traceable error budgets. [ABSTRACT FROM AUTHOR]