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In this study, we introduce the concept and construction of an innovative Digital Miniature Cathode Ray Magnetometer designed for the precise detection of magnetic fields. This device addresses several limitations inherent to magnetic probes such as D.C. offset, nonlinearity, temperature drift, sensor aging, and the need for frequent recalibration, while capable of operating in a wide range of magnetic fields. The core principle of this device involves the utilization of a charged particle beam as the sensitivity medium. The system leverages the interaction of an electron beam with a scintillator material, which then emits visible light that is captured by an imager. The emitted scintillation light is captured by a CMOS sensor. This sensor not only records the scintillation light but also accurately determines the position of the electron beam, providing invaluable spatial information crucial for magnetic field mapping. The key innovation lies in the combination of electron beam projection, CMOS imager scintillation-based detection, and digital image signal processing. By employing this synergy, the magnetometer achieves remarkable accuracy, sensitivity and dynamic range. The precise position registration enabled by the CMOS sensor further enhances the device's utility in capturing complex magnetic field patterns, allowing for 2D field mapping. In this work, the optimization of the probe's performance is tailored for applications related to the characterization of insertion devices in light sources, including undulators. [ABSTRACT FROM AUTHOR]

We have proposed a structural design for a single photon avalanche diode with a low breakdown voltage. This diode is fabricated using Taiwan Semiconductor Manufacturing Company (TSMC) 0.18 μm HV CMOS technology, and it can maintain a high operating excess voltage in an n-on-p design without requiring any additional customized well layers. The n-on-p type device is particularly advantageous for a 3D-stacked backside illuminated structure and offers excellent photon detection capabilities at longer wavelengths. By incorporating a high doping concentration PDD well layer, we can significantly increase the excess bias, resulting in enhanced photon detection probability in the near-infrared wavelength range, all while maintaining a lower voltage due to a reduction in breakdown voltage. This design also leads to power consumption savings. As a result, our designed device is well-suited for consumer applications such as 3D image rendering and LiDAR technology.

The human eye, sensors, and photoreceptors can be damaged if they are submitted to laser beams with high intensities and low divergence. In the military field, an optical sensor can be damaged by pulsed laser radiations when exposed beyond its capacities. In order to have a protection against such threats, passive optical limiting is used. A mix between a reactive oligomer and a monomer, with methacrylate functions, is studied in the present work giving a thermoset matrix. To prevent the monomer evaporation, which results in the formation of bubbles in the final material, related to the reaction exotherm, an oligomer and a monomer with a high boiling temperature are used as precursors, giving a good alternative to a thermoplastic matrix like polymethyl methacrylate (PMMA). We report the experimental results of transient thermally induced optical nonlinearities (i.e., nonlinear refraction) in methacrylate‐based polymer filters at a nanosecond timescale, focus will be made to compare third order nonlinear refractive index from thermally induced refractive index. Optical filters are obtained by chemical bulk processes. In the present work, both thermoplastics and thermosets matrices were synthesized in order to characterize their optical limiting properties by mean of an appropriate custom‐made optical setup as well as their nonlinear refractive indices measured by the z‐scan technique. Optical measurements in the nonlinear regime are achieved at the wavelength of 1064 nm. To the best of the authors' knowledge, such a work dealing on 3D‐network methacrylate‐based host has never been published. [ABSTRACT FROM AUTHOR]

Microlens array combined with CMOS sensors have recently been the subject of intensive research due to their ability to significantly enhance imaging sensitivity. However, existing microlens arrays suffer from a limited field-of-view, necessitating complex lens assemblies that increase system cost, size and weight. In this study, we present a novel approach utilizing a single layer metalens array composed of low loss and high-index α-Si materials. The metalens array was designed using a phase compensation method to efficiently focus conical light with arbitrary cone angles onto the center pixels of the CMOS sensor. Theoretical analysis demonstrates that the metalens is capable of focusing ± 20° conical light with an impressive efficiency of 83.6 %, which can be extended to arbitrary cone angles. Experimental results reveal a measured focusing efficiency of 73 % under an incidence angle of ± 8.3° for conical light, representing an improvement of 8 % compared to parallel light incidence. This research presents a promising solution for wide-field-of-view metalens arrays in integrated CMOS imaging systems.

An image processing method was employed to obtain wavelength information using light irradiated during camera exposure. Physically, hue (H) and wavelength (W) are closely related. Once the H value is known through image pixel analysis, the wavelength can be obtained. In this paper, the H-W curve was investigated from 400 to 650 nm using raw image data with a complementary metal oxide semiconductor (CMOS) sensor technology. We reconstructed the H-W curve from raw image data based on a demosaicing method with 2 × 2 pixel images. To date, no study has reported on reconstructing the H-W curve using several different interpolation algorithms in the 400~650 nm wavelength region. In addition, several factors affecting the H-W curve with a raw digital image, such as exposure time, aperture, and international organization for standardization (ISO) settings, were investigated for the first time. [ABSTRACT FROM AUTHOR]

Resonant Inelastic X-ray Scattering (RIXS) is a powerful spectroscopic technique to study quantum properties of materials in the bulk. A novel variant of RIXS, called 2D RIXS, enables concurrent measurement of the scattered X-ray spectrum for a wide range of input energies, improving on the typically low throughput of 1D RIXS. In the soft X-ray domain, 2D RIXS demands an X-ray camera system with small pixels, large area, high quantum efficiency and low noise to limit the false detection rate in long duration exposures. We designed and implemented a 7.5 Megapixel back-illuminated CMOS detector with 5 μm pixels and high quantum efficiency in the 200–1,000 eV X-ray energy range for the QERLIN 2D RIXS spectrometer at the Advanced Light Source. The QERLIN beamline and detector are currently in commissioning. The camera noise from in-situ 3 s long dark exposures is 7e− or less and the leakage current is 6.5 × 10−3 e−/(pixel ∙ s). For individual 500 eV X-rays, the expected efficiency is greater than 75% and the false detection rate is ∼1 × 10−5 per pixel.

In this study, a non-linear hue–wavelength (H-W) curve was investigated from 400 to 650 nm. To date, no study has reported on H-W relationship measurements, especially down to the 400 nm region. A digital camera mounted with complementary metal oxide semiconductor (CMOS) image sensors was used. The obtained digital images of the sample were based on an RGB-based imaging analysis rather than multispectral imaging or hyperspectral imaging. In this study, we focused on the raw image to reconstruct the H-W curve. In addition, several factors affecting the digital image, such as exposure time or international organization for standardization (ISO), were investigated. In addition, cross check of the H-W response using laser was performed. We expect that our method will be useful as an auxiliary method in the future for obtaining the fluor emission wavelength information. [ABSTRACT FROM AUTHOR]

An image processing method was employed to obtain wavelength information using light irradiated during camera exposure. Physically, hue (H) and wavelength (W) are closely related. Once the H value is known through image pixel analysis, the wavelength can be obtained. In this paper, the H-W curve was investigated from 400 to 650 nm using raw image data with a complementary metal oxide semiconductor (CMOS) sensor technology. We reconstructed the H-W curve from raw image data based on a demosaicing method with 2 × 2 pixel images. To date, no study has reported on reconstructing the H-W curve using several different interpolation algorithms in the 400~650 nm wavelength region. In addition, several factors affecting the H-W curve with a raw digital image, such as exposure time, aperture, and international organization for standardization (ISO) settings, were investigated for the first time.

Nuclear energy is a clean and popular form of energy, but leakage and loss of nuclear material pose a threat to public safety. Radiation detection in public spaces is a key part of nuclear security. Common security cameras equipped with complementary metal oxide semiconductor (CMOS) sensors can help with radiation detection. Previous work with these cameras, however, required slow, complex frame-by-frame processing. Building on the previous work, we propose a nuclear radiation detection method using convolution neural networks (CNNs). This method detects nuclear radiation in changing images with much less computational complexity. Using actual video images captured in the presence of a common Tc-99m radioactive source, we construct training and testing sets. After training the CNN and processing our test set, the experimental results show the high performance and effectiveness of our method.

This study focuses on a CMOS sensing system for Radon and alpha radiation, which is based on a semiconductor device that is integrated monolithically on a single chip with the Readout Circuitry, thus allowing fabrication of a low-power and low-cost sensing system. The new sensor is based on a new mosaic design of an array of Floating Gate non-volatile memory-like transistors, which are implemented in a standard CMOS technology, with a single polysilicon layer. The transistors are electrically combined in parallel and are operated at subthreshold, thus achieving very high sensitivity and reduced noise. The sensing system’s architecture and design is presented, along with key operation concepts, characterization, and analysis results. Alpha and radon exposure results are compared to commercial radon detectors. The new sensor, dubbed TODOS-Radon sensor, measures continuously, is battery operated and insensitive to humidity.

High-Voltage CMOS (HVCMOS) sensors, featuring a deep n-well separating the transistors and the depletion region, are intrinsically radiation hard and a good candidate for tracking systems in future high energy physics experiments. In hope of reducing the power density and incorporating more functionality in the same area, we are looking for foundries where HVCMOS sensors can be implemented in smaller feature size. In this paper we report the feasibility study in two MPWs using 55 nm processes. Sensor diodes are designed with deep n-well serving as electrode in Low-Leakage process, and the test results are reported. Design and first results for MPW in 55 nm HVCMOS process will also be described. • First sensor chip implemented using HVCMOS 55 nm process. • Laser signal is observed in CMOS sensor diode using 55 nm process. • Breakdown voltage up to −70 V measured in 55 nm HVCMOS. [ABSTRACT FROM AUTHOR]

Monolithic pixel detectors combine readout electronics and sensor in a single entity of silicon, which simplifies the production procedure and lowers the material budget compared to conventional hybrid pixel detector concepts. Benefiting from the advances in commercial CMOS processes towards large biasing voltage capabilities and the increasing availability of high-resistivity substrates, depleted monolithic active pixel sensors (DMAPS) can cope with the high-rate and high-radiation environments faced in modern high-energy physics experiments. TJ-Monopix2 is the latest iteration of a DMAPS development line designed in 180 nm TowerSemicondutor technology, which features a large scale (2 × 2) cm2 chip divided into (512 × 512) pixels with a pitch of (33 × 33) µm2. All in-pixel electronics are separated from its small collection electrode and process modifications are implemented to improve charge collection efficiency especially after irradiation. The latest laboratory measurements and investigations of a periodic variation in the threshold response relative to the hit arrival time observed for TJ-Monopix2 in typical operating conditions are presented. [ABSTRACT FROM AUTHOR]

Silicon Photomultipliers (SiPMs) are state-of-the-art photon detectors used in particle physics, medical imaging, and beyond. They are sensitive to individual photons in the optical wavelength regime and achieve time resolutions of a few tens of picoseconds, which makes them interesting candidates for timing detectors in tracking systems for particle physics experiments. The Geiger discharges triggered in the sensitive elements of a SiPM, Single-Photon Avalanche Diodes (SPADs), yield signal amplitudes independent of the energy deposited by a photon or ionizing particle. This intrinsically digital nature of the signal motivates its digitization already on SPAD level. A digital SiPM (dSiPM) was designed at Deutsches Elektronen Synchrotron (DESY), combining a SPAD array with embedded CMOS circuitry for on-chip signal processing. A key feature of the DESY dSiPM is its capability to provide hit-position information on pixel level, and one hit time stamp per quadrant at a 3 MHz readout-frame rate. The pixels comprise four SPADs and have a pitch of about 70 μm. The four time stamps are provided by 12 bit Time-to-Digital Converters (TDCs) with a resolution better than 100 ps. The chip was characterized in the laboratory to determine dark count rate, breakdown voltage, and TDC characteristics. Test-beam measurements are analyzed to assess the DESY dSiPMs performance in the context of a 4D-tracking applications. The results demonstrate a spatial hit resolution on a pixel level, a minimum-ionizing particle detection efficiency of about 30 % and a time resolution in the order of 50 ps. [ABSTRACT FROM AUTHOR]

Video stabilization is one of the most important features in consumer cameras. Even simple video stabilization algorithms may need to access the frames several times to generate a stabilized output image, which places a significant burden on the camera hardware. This high-memory-access requirement makes it difficult to implement video stabilization in real time on low-cost camera SoC. Reduction of the memory usage is a critical issue in camera hardware. This paper presents a structure and layout method to efficiently implement video stabilization for low-end hardware devices in terms of shared memory access amount. The proposed method places sub-components of video stabilization in a parasitic form in other processing blocks, and the sub-components reuse data read from other processing blocks without directly accessing data in the shared memory. Although the proposed method is not superior to the state-of-the-art methods applied in post-processing in terms of video quality, it provides sufficient performance to lower the cost of camera hardware for the development of real-time devices. According to my analysis, the proposed one reduces the memory access amount by 21.1 times compared to the straightforward method. [ABSTRACT FROM AUTHOR]

With the application of four optical CMOS sensors, it was possible to capture the trajectory of an endoscopic tool during an in vitro surgical experiment on a cardiovascular preparation. This was due to the possibility of obtaining a path when a reflective marker was attached. In the work, APAS (Ariel Performance Analysis System) software and DLT (direct linear transformation) algorithm were used. This made it possible to acquire kinematic inputs to the computational model of dynamics, which enabled, regardless of the type of surgical robot structure, derivation of the analogous motion of an endoscopic effector due to the mathematical transformation of the trajectory to joints coordinates. Experiments were carried out with the participation of a practiced cardiac surgeon employing classic endoscopic instruments and robot surgical systems. The results indicated by the experiment showed that the inverse task of kinematics of position for the surgical robot with RCM (remote center of motion) structure was solved. The achieved results from the experiment were used as inputs for deriving a numerical dynamics model of surgical robot during transient states that was obtained by applying the finite element method and by driving dynamics moments acquired through the block diagrams method using a steering system with DC (direct current) motor and PID (proportional–integral–derivative) controller. The results section illustrates the course of kinematic values of endoscopic tools which were employed to apply numerical models as inputs, the course of the driving torque of the model of the surgical robot that enabled the selection of the drive system and the strength values, stresses and displacements according to von Mises hypothesis in its structure during the analysis of transient states that made it possible to establish the strength safety of the surgical robot. For the conducted experiments, the accuracy was ±2 [mm]. In the paper, the employment of optical CMOS sensors in surgical robotics and endoscopy is discussed. The paper concludes that the usage of optical sensors for determining inputs for numerical models of dynamics of surgical robots provides the basis for setting the course of physical quantities that appear in their real object structure, in manners close to reality. [ABSTRACT FROM AUTHOR]

Comparing with the application of charge coupled device (CCD) sensor, a kind of interference stripe noise (ISN) can be observed easily from the complementary metal-oxide-semiconductor (CMOS) sensor-based digital holographic measurement (DHM) system because a series of optic coatings and filters are used in front of that sensor in order to improve its imaging effect. The improper assembly or the micro manufacturing error of these optic components may create the unexpected interference phenomena in the imaging sensor. To reduce that noise, an effective image processing method is developed. On one hand the Laplacian pyramid method is used to highlight the ISN and a cartoon-texture decomposition technique is carried out to remove the additive ISN. On the other hand, an improved Lee filtering is performed to restrain the multiplicative ISN. Extensive experiment results have shown that the image quality can be improved after the ISN reduction and this method is fit for solving a deionized water temperature estimation application where the texture complexity of target image is relatively low.

This paper presents a 288-pixel retinal prosthesis (RP) chip implemented in a 0.18 μm CMOS process. The proposed light-to-stimulus duration converter (LSDC) and biphasic stimulator generate a wide range of retinal stimuli proportional to the incident light intensity at a low supply voltage of 1V. The implemented chip shows 25.5 dB dynamic stimulation range and the state-of-the art low power consumption of 4.49 nW/pixel. Ex-vivo experiments were performed with a mouse retina and patch-clamp recording. The electrical artifact recorded by the patch electrode demonstrates that the proposed chip can generate electrical stimuli that have different pulse durations depending on the light intensity. Correspondingly, the spike counts in a retinal ganglion cell (RGC) were successfully modulated by the brightness of the light stimuli. [ABSTRACT FROM AUTHOR]

In this study, a non-linear hue–wavelength (H-W) curve was investigated from 400 to 650 nm. To date, no study has reported on H-W relationship measurements, especially down to the 400 nm region. A digital camera mounted with complementary metal oxide semiconductor (CMOS) image sensors was used. The obtained digital images of the sample were based on an RGB-based imaging analysis rather than multispectral imaging or hyperspectral imaging. In this study, we focused on the raw image to reconstruct the H-W curve. In addition, several factors affecting the digital image, such as exposure time or international organization for standardization (ISO), were investigated. In addition, cross check of the H-W response using laser was performed. We expect that our method will be useful as an auxiliary method in the future for obtaining the fluor emission wavelength information.

In this paper, we describe several key problems in the design of a real 3D display system with sensors (RDSS) and details of matching the parameters to generate 3D images. We also illustrate the feasibility of using light fields to reconstruct 3D images. Additionally, we propose a real 3D display based on optical field reconstruction that also solves the problems of fuzzy images and low mechanical stability caused by the scattering characteristics in an optical field display. We acquire images through sensors and project them to a high-speed rotating mirror through digital light processing (DLP) after computer processing. At the same time, DLP is used to project images to the horizontal space, so that they can be observed by human eyes without auxiliary equipment. We find the best parameters for achieving a clear and stable image by comparing different experimental data. The matching parameters provided in this study can greatly reduce the cost of real 3D display systems that are easily usable and realizable and can be widely used in advertising, exhibitions, and other applications. [ABSTRACT FROM AUTHOR]

Visible light positioning (VLP) is a cost-effective solution to the increasing demand for real-time indoor positioning. However, owing to high computational costs and complicated image processing procedures, most of the existing VLP systems fail to deliver real-time positioning ability and better accuracy for image sensor-based large-area indoor environments. In this study, an effective method is proposed to receive coordinate information from multiple light-emitting diode (LED) lights simultaneously. It provides better accuracy in large experimental areas with many LEDs by using a smartphone-embedded image sensor as a terminal device and the existing LED lighting infrastructure. A flicker-free frequency shift on–off keying line coding modulation scheme was designed for the positioning system to ensure a constant modulated frequency. We tested the performance of the decoding accuracy with respect to vertical and horizontal distance, which utilizes a rolling shutter mechanism of a complementary metal-oxide-semiconductor image sensor. The experimental results of the proposed positioning system can provide centimeter-level accuracy with low computational time, rendering it a promising solution for the future direction of large-area indoor positioning systems. [ABSTRACT FROM AUTHOR]

• We provided discussions on the research of CMOS sensors, and the method to enhance the focusing efficiency of photo-sensitive pixels. • Conical light field can be compensated by using a concave lens phase while employing convex metalens phase distribution for parallel beams. • Our metalens design have potential application in integration of the metalens with CMOS sensors. Microlens array combined with CMOS sensors have recently been the subject of intensive research due to their ability to significantly enhance imaging sensitivity. However, existing microlens arrays suffer from a limited field-of-view, necessitating complex lens assemblies that increase system cost, size and weight. In this study, we present a novel approach utilizing a single layer metalens array composed of low loss and high-index α-Si materials. The metalens array was designed using a phase compensation method to efficiently focus conical light with arbitrary cone angles onto the center pixels of the CMOS sensor. Theoretical analysis demonstrates that the metalens is capable of focusing ± 20° conical light with an impressive efficiency of 83.6 %, which can be extended to arbitrary cone angles. Experimental results reveal a measured focusing efficiency of 73 % under an incidence angle of ± 8.3° for conical light, representing an improvement of 8 % compared to parallel light incidence. This research presents a promising solution for wide-field-of-view metalens arrays in integrated CMOS imaging systems. [ABSTRACT FROM AUTHOR]

Video stabilization is one of the most important features in consumer cameras. Even simple video stabilization algorithms may need to access the frames several times to generate a stabilized output image, which places a significant burden on the camera hardware. This high-memory-access requirement makes it difficult to implement video stabilization in real time on low-cost camera SoC. Reduction of the memory usage is a critical issue in camera hardware. This paper presents a structure and layout method to efficiently implement video stabilization for low-end hardware devices in terms of shared memory access amount. The proposed method places sub-components of video stabilization in a parasitic form in other processing blocks, and the sub-components reuse data read from other processing blocks without directly accessing data in the shared memory. Although the proposed method is not superior to the state-of-the-art methods applied in post-processing in terms of video quality, it provides sufficient performance to lower the cost of camera hardware for the development of real-time devices. According to my analysis, the proposed one reduces the memory access amount by 21.1 times compared to the straightforward method.

In this study a specially revised version of the concept for measuring the angle-of-arrival (AOA) of incidence light was used, which is particularly well suited for the construction of trigonometric sensor concepts with external dimensions of only a few millimeters. The aim of the study was to break down the interrelationships for the overall systemically achievable accuracies. The study therefore focused on the lowest possible power consumption of the LED light source used, minimum component dimensions and quantities, outline of the practicable minimum distances between LED light source and integrated sensor unit, robustness of the sensor against gradients and intensity changes in lighting, illumination intensity and sensor noise, as well as the requirements for the precision of the mechanical components used. It could be shown that the key limiting factor isn't the optical/electronic precision of the CMOS sensor concept used, but the finite precision of the mechanical components. • A high precision light angle measurement for ultra miniaturized applications was designed. • Errors due to illumination gradients were investigated, evaluated and compensated. • The measurement principle reaches up to 16 bits of maximum measurement resolution. • The measuring principle can be extended on a vast majority of optical measurements. • Measurements without lenses, reflectors or lighting arrays are possible. [ABSTRACT FROM AUTHOR]

This paper introduces a new method to measure whole cycle length change non-destructively and continuously using a digital image analysis system. The macroscale length changes of mortars containing different shrinkage-reducing admixture (SRA) dosages (0%, 1%, 2% and 5% by cement weight) were first determined using a complementary metal oxide semiconductor (CMOS) image sensor under alternating dry and wet curing conditions. After that, the length change was calculated using developed digital image processing technology (DIPT) software. After that, several significant conclusions could be drawn by combining with the results of systematic tests of the macroscopic and microscale physical properties of the cement mortar using X-ray diffraction, scanning electron microscopy, mercury intrusion porosimetry (MIP) and nuclear magnetic resonance (NMR) methods. The test results indicated that SRAs exhibited significant effects on the shrinkage inhibition of cement mortars, whereas the shrinkage reduction behaviour was also affected by varying the curing conditions. The MIP and NMR analyses demonstrated that SRAs reduced the irreversible shrinkage of the cement mortars by decreasing the volume percentage of the 3–50 nm pores and promoting the conversion of calcium silicate hydrate gel from an oligomeric to a high polymerization state thereby improving the volume stability of cement mortars [ABSTRACT FROM AUTHOR]

We present the manufacturing and utilization of an all-polymer arrayed waveguide grating (AWG) interacting with a fiber Bragg grating (FBG) for battery status monitoring on the example of a 40 Ah lithium-ion battery. The AWG is the main component of a novel low-cost approach for an optical interrogation unit to track the FBG peak wavelength by means of intensity changes monitored by a CMOS linear image sensor, read out by a Teensy 3.2 microcontroller. The AWG was manufactured using laser direct lithography as an all-polymer-system, whereas the FBG was produced by point-by-point femtosecond laser writing. Using this system, we continuously monitored the strain variation of a battery cell during low rate charge and discharge cycles over one month under constant climate conditions and compared the results to parallel readings of an optical spectrum analyzer with special attention to the influence of the relative air humidity. We found our low-cost interrogation unit is capable of precisely and reliably capturing the typical strain variation of a high energy pouch cell during cycling with a resolution of 1 pm and shows a humidity sensitivity of -12.8 pm per %RH. [ABSTRACT FROM AUTHOR]

Visible light positioning (VLP) is a cost-effective solution to the increasing demand for real-time indoor positioning. However, owing to high computational costs and complicated image processing procedures, most of the existing VLP systems fail to deliver real-time positioning ability and better accuracy for image sensor-based large-area indoor environments. In this study, an effective method is proposed to receive coordinate information from multiple light-emitting diode (LED) lights simultaneously. It provides better accuracy in large experimental areas with many LEDs by using a smartphone-embedded image sensor as a terminal device and the existing LED lighting infrastructure. A flicker-free frequency shift on–off keying line coding modulation scheme was designed for the positioning system to ensure a constant modulated frequency. We tested the performance of the decoding accuracy with respect to vertical and horizontal distance, which utilizes a rolling shutter mechanism of a complementary metal-oxide-semiconductor image sensor. The experimental results of the proposed positioning system can provide centimeter-level accuracy with low computational time, rendering it a promising solution for the future direction of large-area indoor positioning systems.

Recent research into miniaturized illumination sources has prompted the development of alternative microscopy techniques. Although they are still being explored, emerging nano-light-emitting-diode (nano-LED) technologies show promise in approaching the optical resolution limit in a more feasible manner. This work presents the exploration of their capabilities with two different prototypes. In the first version, a resolution of less than 1 µm was shown thanks to a prototype based on an optically downscaled LED using an LED scanning transmission optical microscopy (STOM) technique. This research demonstrates how this technique can be used to improve STOM images by oversampling the acquisition. The second STOM-based microscope was fabricated with a 200 nm GaN LED. This demonstrates the possibilities for the miniaturization of on-chip-based microscopes.

(a) Schematic diagram of industrial optical industry. (a) A 5 mm diameter miniature endoscopy using CMOS sensor. (c) Industrial component. (d) Testing result of a piece of enameled wire stuck on the inner surface of industrial component, which indicates the newly-designed endoscopic device enables clear observation with resolution greater than 0.02 mm. • As an essential inspection device widely used in modern industrial fields, optical endoscopy normally suffers from the intrinsic contradictory between the diameter of tube and the visual resolution. • In this article, we report a newly-designed 5 mm diameter optical endoscopy with CMOS sensor, which enables capturing clear pictures with resolution greater than 57 lp/mm. • The proposed modality holds great potentials to accurately diagnose the interior structure of the small-scale industrial components. In the industrial field, an endoscope is typically employed for the observation and inspection of internal defect and corrosion of an engine and chemical plant. Current industrial optical endoscopes normally use CMOS sensor which offers best performance as an image pickup device. Here we report experimental demonstration of an industrial endoscope modality consisting of a 5 mm diameter rigid tube and 1280 × 960 pixels CMOS camera, which enables accurate diagnosis of small-scale industrial components with hollow shape. As a proof of concept, we successfully perform arc-surface imaging at a resolution of 57 lp/mm and ± 30° field of view. Finally, potentially applying the wave-front coding method to extend the depth of field of endoscopic system is comprehensively discussed. [ABSTRACT FROM AUTHOR]

Abstract Small fields and sharp dose gradients typically encountered in proton irradiation for preclinical research require high spatial resolution dosimetric measurements, especially below 10 mm beam diameter. This study aims to characterize a complementary metal oxide semiconductor (CMOS) sensor for fluence measurement of small radiation fields (2 mm, 5 mm and 10 mm diameter) delivered by a 25 MeV proton beam dedicated to preclinical irradiations. The beam fluence was characterized in air with a MIMOSA28 CMOS sensor and EBT3 films and compared to Geant4 simulations. The measured flatness for the 10 mm field was found within ± 2.5 % with both the CMOS sensor and EBT3 films. Lateral profiles were in agreement within a distance of 0.1 mm between the two detectors and Geant4 simulations. Also, with a fixed particle rate, the fluence measured by the CMOS sensor was constant at the plateau of the Bragg curve, regardless the field size, while EBT3 showed a 10% increased fluence for the 2 mm collimated beam. The CMOS sensor demonstrated a high spatial resolution and its fluence-response is independent of the radiation field sizes that seems promising for future developments in dosimetry of small field proton beams for precise irradiation platforms dedicated to preclinical research, as well as in nuclear research and laser accelerated particle beam characterization Highlights • Use of the MIMOSA28 CMOS sensor for low energy proton fluence measurement. • MIMOSA28 CMOS sensors have the desired properties such as high spatial resolution and field size independence. • MIMOSA28 CMOS sensors are suitable for small field applications. [ABSTRACT FROM AUTHOR]

Multispectral imaging (MI) techniques are being used very often to identify different properties of nature in several domains, going from precision agriculture to environmental studies, not to mention quality inspection of pharmaceutical production, art restoration, biochemistry, forensic sciences or geology, just to name some. Different implementations are commercially available from the industry and yet there is quite an interest from the scientific community to spread its use to the majority of society by means of cost effectiveness and ease of use for solutions. These devices make the most sense when combined with unmanned aerial vehicles (UAVs), going a step further and alleviating repetitive routines which could be strenuous if traditional methods were adopted. In this work, a low cost and modular solution for a multispectral camera is presented, based on the use of a single panchromatic complementary metal oxide semiconductor (CMOS) sensor combined with a rotating wheel of interchangeable band pass optic filters. The system is compatible with open source hardware permitting one to capture, process, store and/or transmit data if needed. In addition, a calibration and characterization methodology has been developed for the camera, allowing not only for quantifying its performance, but also able to characterize other CMOS sensors in the market in order to select the one that best suits the budget and application. The process was experimentally validated by mounting the camera in a Dji Matrice 600 UAV to uncover vegetation indices in a reduced area of palm trees plantation. Results are presented for the normalized difference vegetation index (NDVI) showing a generated colored map with the captured information.

In order to develop equipment adapted to the aircraft pulse final assembly line, a vision-based aircraft transport platform system is developed. This article explores a guiding method between assembly stations which is low-cost and easy to change routes by using two-dimensional code and two complementary metal oxide semiconductor (CMOS) cameras. The two cameras installed on the front and back of the platform read the two-dimensional code containing station information to guide the platform. In the process of guiding, the theoretical position and posture of the platform at each assembly station are known, but there is a difference between the actual and theoretical values due to motion errors. To reduce the influence of the deviation on the navigation route, a localization method is proposed based on the two-dimensional images captured by the cameras. Canny edge detection is applied to the processed image to obtain the position of the two-dimensional code in the image, which can measure the angle/distance deviation of the platform. Then, the computer can locate the platform precisely by the information in the two-dimensional code and the deviation measured by the image. To verify the feasibility of the proposed method, experiments have been performed on the developed platform system. The results show that the distance and angle errors of the platform are within ±10 mm and ±0.15° respectively.

Laser lights have been used by dermatologists for tattoo removal through photothermal interactions. However, most clinical studies used a visual scoring method to evaluate the tattoo removal process less objectively, leading to unnecessary treatments. This study aimed to develop a simple and quantitative imaging method to monitor the degree of tattoo removal in in vivo skin models. Sprague Dawley rat models were tattooed with four different concentrations of black inks. Laser treatment was performed weekly on the tattoos using a wavelength of 755 nm over six weeks. Images of non-treated and treated samples were captured using the same method after each treatment. The intensities of the tattoos were measured to estimate the contrast for quantitative comparison. The results demonstrated that the proposed monitoring method quantified the variations in tattoo contrast after the laser treatment. Histological analysis validated the significant removal of tattoo inks, no thermal injury to adjacent tissue, and uniform remodeling of epidermal and dermal layers after multiple treatments. This study demonstrated the potential of the quantitative monitoring technique in assessing the degree of clearance level objectively during laser treatments in clinics.