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Near‐infrared (NIR) photodetection and imaging have sparked significant interests across a wide range of applications. While silicon photodiodes are commonly employed, the small light absorption coefficients of Si in NIR severely limit the performance, especially in the case of thin active Si layers. Although various light harvesting techniques are proposed to increase light absorption of Si, pixel‐level strategy for enhanced NIR imaging is still challenging in CMOS image sensors (CISs) with a pixel size in only a micron scale. In this paper, plasmonic metasurfaces are intimately integrated on top of 2.3 µm thick Si active regions of the pixels of a backside illumination (BI)‐CIS for NIR imaging for the first time. 200% improved photoresponsivity is obtained in experiments in such a planar Si layer rather than patterning the Si layer with potential damage to the active region. Numerical simulation results reveal highly enhanced light intensity in the thin active Si layer due to the presence of plasmonic metasurfaces. Significantly improved imaging brightness and signal‐to‐noise ratio of NIR imaging are demonstrated under both laser and LED illumination. This CMOS‐compatible technique is expected to hold promising potentials in applications including machine vision, iris certification, light detection and ranging (LiDAR), and optical communication in data centers. [ABSTRACT FROM AUTHOR]

This paper presents a two-step single-slope (TS-SS) analog-to-digital converter (ADC) for CMOS image sensors (CIS). The proposed TS-SS ADC divides the pixel signal into small and large signal regions using a precomparator. When quantizing large pixel signals, the TS-SS ADC enters accelerated mode, which leverages the differential topology of the ramp generator to speed up quantization. The accelerated mode reduces the row cycle, resulting in a 31.3% reduction at 320 MHz clock from 27.3 to 18.75 µs. The designed 12-bit TS-SS ADC was designed in a 110 nm 1P4M CMOS technology, and its linearity was verified by process corner post-simulation and Monte Carlo simulation. [ABSTRACT FROM AUTHOR]

Star sensors play a crucial role as high-precision optical attitude navigation devices in satellite attitude control systems. The CMOS image sensor is an important component of the imaging system of the star sensor and experiences performance degradation due to the total ionizing dose effect and displacement damage effect in the radiation environment of its long-term operational workspace. As a result, the detection capability and attitude positioning accuracy of the star sensor gradually deteriorate. The performance of CMOS image sensors can be partially restored after annealing but the impact on the performance of star sensors is unclear. This study conducted 100 MeV proton irradiation experiments with different fluences on CMOS image sensors and performed room temperature and high temperature annealing treatments. By testing and analyzing the performance of star sensors equipped with irradiated and different annealing treatments on CMOS image sensors, the impact mechanism of CMOS image sensor radiation damage and annealing recovery on the performance variation of star sensors was obtained. This study provides theoretical support for reliability of long-term in-orbit star sensors. [ABSTRACT FROM AUTHOR]

Optical biosensors have emerged as a powerful tool in analytical biochemistry, offering high sensitivity and specificity in the detection of various biomolecules. This article explores the advancements in the integration of optical biosensors with microfluidic technologies, creating lab-on-a-chip (LOC) platforms that enable rapid, efficient, and miniaturized analysis at the point of need. These LOC platforms leverage optical phenomena such as chemiluminescence and electrochemiluminescence to achieve real-time detection and quantification of analytes, making them ideal for applications in medical diagnostics, environmental monitoring, and food safety. Various optical detectors used for detecting chemiluminescence are reviewed, including single-point detectors such as photomultiplier tubes (PMT) and avalanche photodiodes (APD), and pixelated detectors such as charge-coupled devices (CCD) and complementary metal–oxide–semiconductor (CMOS) sensors. A significant advancement discussed in this review is the integration of optical biosensors with pixelated image sensors, particularly CMOS image sensors. These sensors provide numerous advantages over traditional single-point detectors, including high-resolution imaging, spatially resolved measurements, and the ability to simultaneously detect multiple analytes. Their compact size, low power consumption, and cost-effectiveness further enhance their suitability for portable and point-of-care diagnostic devices. In the future, the integration of machine learning algorithms with these technologies promises to enhance data analysis and interpretation, driving the development of more sophisticated, efficient, and accessible diagnostic tools for diverse applications. [ABSTRACT FROM AUTHOR]

CMOS image sensors in optical payloads are susceptible to single-event effects when irradiated by high-energy protons from the spatial radiation environment. Single-event transients in images primarily manifest as bright spots, and the characteristics of transient bright spots generated under different incident conditions exhibit some differences. In this study, we conducted proton irradiation experiments on CMOS image sensors at different energy levels and incident angles. The characteristics of single-event transient bright spots generated under various incident conditions were extracted and analysed in detail. Furthermore, the abnormal phenomena of different functional modules of CMOS image sensors observed during proton irradiation experiments were investigated. The results of this study establish the foundation for classifying the detected targets and transient bright spots, indicating that the validation of CMOS image sensor radiation reliability should account for functional abnormalities resulting from high-energy proton irradiation. [ABSTRACT FROM AUTHOR]

The proliferation of smartphones and the widespread use of camera modules necessitate complementary metal-oxide-semiconductor (CMOS) image sensors with high pixel density. The recent competitive race to miniaturize pixels has enabled commercial CMOS sensors with submicron pixels to reach sizes as small as 0.5 μ m. However, further downsizing towards subwavelength pixels faces fundamental challenges as the conventional focus-and-filter approach suffers from the diminishing focusing ability of conventional microlens arrays and optical efficiency constraints imposed by absorptive color filters. Nanophotonic color routers have emerged to overcome these challenges via efficient spatio-spectral splitting, thereby directing incident light into corresponding pixels. In particular, recent developments in free-form device optimization methods enable the design of highly efficient color routers by exploring a large combinatorial design space, which was previously considered to be intractable with conventional design methods. In this review, we comprehensively introduce a multitude of research achievements in the field of nanophotonic color routers for CMOS image sensors with a special emphasis on their design methodologies. [ABSTRACT FROM AUTHOR]

Remote control engineering in industry usually requires cameras to assist target identification and detection, but the cameras working in nuclear environments face the threat of radiation-induced degradation. Both γ- and X-rays in nuclear environments will cause ionizing radiation damage, but the difference in degradation of camera’s performance induced by ionizing radiation damage with equivalent total ionizing dose (TID) of these two rays is unclear, which is crucial for the evaluation of camera performance in a nuclear radiation environment. In order to figure out the degradation of CMOS cameras by ionization radiation damage under different rays, this study conducted irradiation experiments on CMOS image sensors under X-ray with 10 keV and 60Co-γ ray with 1.25 MeV, respectively, and then tested and calculated the resolution of camera based on this CMOS image sensor. After comparing and analyzing the results, it was found that the dark current and full well capacity of the CIS, as well as the resolution of the camera, were more severely degraded after X-ray irradiation. Further analysis found that the interface dose enhancement effect of X-ray, as well as the generation of high-density oxide trapped charges in the gate oxide, aggravated the degradation of full well capacity on the CIS after X-ray irradiation, resulting in more severe degradation in the resolution of the CMOS camera. This study provides theoretical basis for the safety and reliability evaluation of cameras in strong nuclear radiation environments. [ABSTRACT FROM AUTHOR]

We present robust pixel design methodologies for a vertical avalanche photodiode-based CMOS image sensor, taking account of three critical practical factors: (i) "guard-ring-free" pixel isolation layout, (ii) device characteristics "insensitive" to applied voltage and temperature, and (iii) stable operation subject to intense light exposure. The "guard-ring-free" pixel design is established by resolving the tradeoff relationship between electric field concentration and pixel isolation. The effectiveness of the optimization strategy is validated both by simulation and experiment. To realize insensitivity to voltage and temperature variations, a global feedback resistor is shown to effectively suppress variations in device characteristics such as photon detection efficiency and dark count rate. An in-pixel overflow transistor is also introduced to enhance the resistance to strong illumination. The robustness of the fabricated VAPD-CIS is verified by characterization of 122 different chips and through a high-temperature and intense-light-illumination operation test with 5 chips, conducted at 125 °C for 1000 h subject to 940 nm light exposure equivalent to 10 kLux. [ABSTRACT FROM AUTHOR]

Over the past decade, significant advancements in high-resolution imaging technology have been driven by the miniaturization of pixels within image sensors. However, this reduction in pixel size to submicrometer dimensions has led to decreased efficiency in color filters and microlens arrays. The development of color routers that operate at visible wavelengths presents a promising avenue for further miniaturization. Despite this, existing color routers often encounter severe interpixel crosstalk, around 70 %, due to the reliance on periodic boundary conditions. Here, we present interpixel crosstalk-minimized color routers that achieve an unprecedented in-pixel optical efficiency of 87.2 % and significantly reduce interpixel crosstalk to 2.6 %. The color routers are designed through adjoint optimization, incorporating customized incident waves to minimize interpixel crosstalks. Our findings suggest that our color router design surpasses existing color routing techniques in terms of in-pixel optical efficiency, representing a crucial step forward in the push toward commercializing the next generation of solid-state image sensors. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) stacking using hybrid bonding is the most scalable method for 3D integration. As the hybrid bonding pad width is reduced to adopt a higher number of interconnections, the ability to extract the contact resistivity at the bonding interface with high accuracy is critical. Using specific electrical test structures and a dedicated methodology, we extract the contact resistivity for hybrid bonding pad widths down to 400 nm for a Cu/SiO2 hybrid bonding integration. Very low values around 10−11 Ω cm2 were obtained for our reference process, close to the those of Cu grain boundaries. A comprehensive analysis of the experimental contact resistivity is performed to understand its increase with the Cu recess within the bonding pads. Based on thermomechanical simulations and experimental results, the influence of both the pad thickness and initial dishing on the interface closure is discussed, for bonding pad width down to 100 nm. These analyses enable us to propose process conditions to reach low contact resistivity with low sensitivity to wafer-to-wafer overlay for hybrid bonding stacking using bonding pad widths down to 100 nm. [ABSTRACT FROM AUTHOR]

Silicon is the dominant material in complementary metal-oxide-semiconductor (CMOS) imaging devices because of its outstanding electrical and optical properties, well-established fabrication methods, and abundance in nature. However, with the ongoing trend toward electronic miniaturization, which demands smaller pixel sizes in CMOS image sensors, issues, such as crosstalk and reduced optical efficiency, have become critical. These problems stem from the intrinsic properties of Si, particularly its low absorption in the long wavelength range of the visible spectrum, which makes it difficult to devise effective solutions unless the material itself is changed. Recent advances in optical metasurfaces have offered new possibilities for solving these problems. In this study, we propose color arrestor pixels (CAPs) as a new class of color image sensors whose composite spectral responses directly mimic those of the human eye. The key idea is to employ linearly independent combinations of standardized color matching functions. These new basis functions allow our device to reproduce colors more accurately than the currently available image sensors with red-green-blue filters or other metasurface-based sensors, demonstrating an average CIEDE2000 color difference value of only 1.79 when evaluating 24 colors from the Gretag-Macbeth chart under standard illuminant D65. Owing to their high fidelity to the human eye response, CAPs consistently exhibit exceptional color reproduction accuracy under various spectral illumination compositions. With a small footprint of 860 nm height and 221 nm full-color pixel pitch, the CAPs demonstrated high absorption efficiencies of 79 %, 81 %, and 63 % at wavelengths of 452 nm, 544 nm, and 603 nm, respectively, and good angular tolerance. With such a high density of pixels efficiently capturing accurate colors, CAPs present a new direction for optical image sensor research and their applications. [ABSTRACT FROM AUTHOR]

In this paper a novel low power wideband CMOS transimpedance amplifier (TIA) with reduced peaking at low supply voltage has been presented. In the proposed TIA, floating gate MOSFET (FGMOS) and flipped voltage follower (FVF) techniques are employed in folded cascade (FC) based TIA. Both FGMOS and FVF techniques make proposed TIA suitable for low voltage operations. Furthermore, to enhance the − 3 dB bandwidth an inductive peaking technique is incorporated which works without affecting the gain. Moreover, this peaking technique does not alter the noise performance of the circuit. Simulation of the proposed TIA design is conducted using Mentor Graphics with CMOS-based TSMC 0.18 µm technology using 0.3 pF input photodiode capacitor. Simulation results of the proposed TIA demonstrate an enhanced -3 dB bandwidth of 13.2 GHz, showing 41% improvement compared to conventional FC-based TIAs and, a transimpedance gain of 50.5 dBΩ. The input referred noise for the suggested TIA is 21.6 pA√Hz. The proposed circuit consumes 3 mW from 1.2 V power supply. [ABSTRACT FROM AUTHOR]

Optical and electrophysiological methods are widely used in neuroscience to study brain activity. Each technique has its own strengths and weaknesses that complement each other to provide a more comprehensive understanding of neuronal activity. To this end, we developed an implantable CMOS image sensor device with an integrated carbon electrode for the simultaneous measurement of fluorescence and extracellular signals. The device is composed of a 450 × 1660 µm CMOS chip and micro-LED secured to a flexible printed circuit substrate. The chip has an imaging surface measuring 900 × 300 µm2, comprising 120 × 90 pixels recording at 10 frames per second. An absorption filter film was placed on top of the imaging surface to block excitation light. The device was coated with parylene-C for waterproofing and, finally, the coating film was readily turned into carbon electrodes by laser carbonization. We characterized the lasercarbonized electrodes by cyclic voltammetry, electrochemical impedance spectroscopy, and X-ray photoelectron spectroscopy to confirm carbonization. We then demonstrated simultaneous in vivo recording of fluorescence and extracellular signals in hippocampus CA1 using the device. [ABSTRACT FROM AUTHOR]

In this study, we developed and demonstrated a millimeter-wave electric field imaging system using an electro-optic crystal and a highly sensitive polarization measurement technique using a polarization image sensor, which was fabricated using a 0.35-µm standard CMOS process. The polarization image sensor was equipped with differential amplifiers that amplified the difference between the 0° and 90° pixels. With the amplifier, the signal-to-noise ratio at low incident light levels was improved. Also, an optical modulator and a semiconductor optical amplifier were used to generate an optical local oscillator (LO) signal with a high modulation accuracy and sufficient optical intensity. By combining the amplified LO signal and a highly sensitive polarization imaging system, we successfully performed millimeter-wave electric field imaging with a spatial resolution of 30 × 60 µm at a rate of 1 FPS, corresponding to 2400 pixels/s. [ABSTRACT FROM AUTHOR]

A prevention and control tracking system based on three-dimensional (3D) face recognition was designed to improve the target tracking accuracy of the prevention and control tracking system. The ARM control chip of TMS320DM6446 was selected as the control chip of the ARM control module. The CMOS image acquisition sensor of the image acquisition module collected face images. The collected images were transmitted to the 3D face recognition module. The 3D face recognition module used the Gabor wavelet algorithm to extract the 3D face contour features of the face image. Moreover, the LDA algorithm was used to recognize faces based on 3D face contour features. The 3D face recognition results were compared with the faces in the face library to determine whether prevention and control tracking were necessary. When prevention and control tracking was needed, the GPS tracking and positioning module embedded in the mobile device terminal of the target object was started. The GPS tracking and positioning module was used to prevent and control the tracking of the target. The results of prevention and control tracking were displayed to the system users using a VGA display. The experimental results indicated that the designed system could accurately recognize faces and achieve prevention and control tracking of the target based on the face recognition results. [ABSTRACT FROM AUTHOR]

The resolution of Si complementary metal–oxide–semiconductor field-effect transistor (C-MOSFET) image sensors (CISs) has been intensively enhanced to follow the technological revolution of smartphones, AI devices, autonomous cars, robots, and drones, approaching the physical and material limits of a resolution increase in conventional Si CISs because of the low quantum efficiency (i.e., ~40%) and aperture ratio (i.e., ~60%). As a novel solution, a hybrid organic–Si image sensor was developed by implementing B, G, and R organic photodiodes on four n-MOSFETs for photocurrent sensing. Photosensitive organic donor and acceptor materials were designed with cost-effective small molecules, i.e., the B, G, and R donor and acceptor small molecules were Coumarin6 and C_60, DMQA and MePTC, and ZnPc and TiOPc, respectively. The output voltage sensing margins (i.e., photocurrent signal difference) of the hybrid organic–Si B, G, and R image sensor pixels presented results 17, 11, and 37% higher than those of conventional Si CISs. In addition, the hybrid organic–Si B, G, and R image sensor pixels could achieve an ideal aperture ratio (i.e., ~100%) compared with a Si CIS pixel using the backside illumination process (i.e., ~60%). Moreover, they may display a lower fabrication cost than image sensors because of the simple image sensor structure (i.e., hybrid organic–Si photodiode with four n-MOSFETs). [ABSTRACT FROM AUTHOR]

To translate near-infrared (NIR) and shortwave infrared (SWIR) fluorescence imaging into the clinic, the paired imaging device needs to detect trace doses of fluorescent imaging agents. Except for the filtration scheme and excitation light source, the image sensor used will finally determine the detection limitations of NIR and SWIR fluorescence imaging systems. In this review, we investigate the current state-of-the-art image sensors used in NIR and SWIR fluorescence imaging systems and discuss the advantages and limitations of their characteristics, such as readout architecture and noise factors. Finally, the imaging performance of these image sensors is evaluated and compared. [ABSTRACT FROM AUTHOR]

Since 2016, we have worked on the development of short-wavelength infrared (SWIR) type II superlattice (T2SL) photodetectors that can utilize night airglow. In addition to the normal SWIR band, the photodetector can detect wavelengths longer than 1.7 µm, which indium gallium arsenide sensors cannot detect, and can effectively utilize illumination by atmospheric phenomena, often called night airglow. To confirm its technical feasibility, we fabricated T2SL single-pixel pin-photodiode experimental samples based on the results of T2SL structural simulation. Using these samples, we obtained various data such as dark current density and spectral sensitivity. On the basis of the data, we considered the appropriate structural parameters and operating conditions of the SWIR T2SL photodetector. Finally, we fabricated a focal plane array with 640 × 512 pixels and confirmed that the photodetector can obtain clear images. [ABSTRACT FROM AUTHOR]

CMOS image sensor (CIS) semiconductor products are integral to mobile phones and photographic devices, necessitating ongoing enhancements in efficiency and quality for superior photographic outcomes. The presence of white pixels serves as a crucial metric for assessing CIS product performance, primarily arising from metal impurity contamination during the wafer production process or from defects introduced by the grinding blade process. While immediately addressing metal impurity contamination during production presents challenges, refining the handling of defects attributed to grinding blade processing can notably mitigate white pixel issues in CIS products. This study zeroes in on silicon wafer manufacturers in Taiwan, analyzing white pixel defects reported by customers and leveraging machine learning to pinpoint and predict key factors leading to white pixel defects from grinding blade operations. Such pioneering practical studies are rare. The findings reveal that the classification and regression tree (CART) and random forest (RF) models deliver the most accurate predictions (95.18%) of white pixel defects caused by grinding blade operations in a default parameter setting. The analysis further elucidates critical factors like grinding load and torque, vital for the genesis of white pixel defects. The insights garnered from this study aim to arm operators with proactive measures to diminish the potential for customer complaints. [ABSTRACT FROM AUTHOR]

This paper proposes a power‐optimized column‐parallel cyclic analog to digital converter (ADC) for complementary metal oxide semiconductors (CMOS) image sensor readout circuits. The design combines a 2.5‐bit/cycle architecture with a comparator shutdown technique based on the comparator‐based switched‐capacitor (CBSC) circuits, which results in a significant reduction in the operating time of the threshold detection comparator compared with conventional CBSC circuits. This reduction in operating time leads to power savings as the threshold detection comparator can be shut down quickly. The paper also presents a comprehensive analysis of the nonideal factors of CBSC circuits and the coarse and fine conversion allocation scheme. The 10‐bit two‐stage comparator‐based cyclic ADC is designed in a 110 nm 1P4 M CMOS technology. Simulation results show that the effective number of bit (ENOB) is 9.7 bits, with each column consuming 103 μ$$ \upmu $$W of power. The proposed cyclic ADC has a figure of merit (FOM) of 123 fJ/conv‐step. Compared with conventional structures, the proposed design reduces the power consumption of the ADC by 34.3% while maintaining the same level of performance. [ABSTRACT FROM AUTHOR]

TDI CMOS image sensors are the most widely used photodetectors in space earth observation and multispectral imaging. The displacement damage caused by high-energy proton irradiation in the space environment leads to the continuous degradation of TDI CMOS image sensor parameters, seriously affecting its performance, reliability, and service life. This paper focuses on a space-based TDI CMOS image sensor chip and carries out 3 MeV proton irradiation tests and post-irradiation annealing tests to obtain the change rules of optical and electrical parameters. The degradation mechanism of sensitive parameters of TDI CMOS image sensors caused by proton irradiation is analyzed, and the sensitive region of proton displacement damage are discussed. The study demonstrates that after proton irradiation, the parameters especially full well capacity and temporal dark noise of the device degrade less, with small sensitivity to proton irradiation. However, the dark current, CTE, and pixel column FPN significantly degrade, and the degree of degradation is linearly related to the proton irradiation dose. In addition, the test also obtained the short-term and long-term annealing changes of sensitive parameters after proton irradiation of TDI CMOS image sensors, providing scientific advice for TDI CMOS image sensors space proton radiation effect tests and evaluations. The research results of this paper provide important references for the evaluation of radiation effects, on-orbit performance estimation, and radiation resistance reinforcement of space-based TDI CMOS image sensors. [ABSTRACT FROM AUTHOR]

To reduce the power consumption of a TDC in high-speed applications, a TDC architecture applied to SS ADC is proposed to reduce redundant counting. This structure can remove the identical part between two rows of pixel signals in a CMOS image sensor by adjusting the start and stop signal of the TDC, which will reduce the number of flipping of D flip-flops in the TDC. This structure requires the simultaneous readout of two rows of pixels in the high-speed CMOS image sensor. In the 110 nm CMOS process, simulation results show that the designed 5-bit TDC achieves an effective number of bits (ENOB) at 4.72 bits and a figure-of-merit (FOM) at 104.7–162.3 fJ/step, with a power consumption ranging from 60 µW to 93 µW. Compared with traditional counting methods, the proposed TDC can reduce counting power consumption by 30%. [ABSTRACT FROM AUTHOR]

To develop materials with improved optical qualities and tunable refractive indices that can be utilized to control the behavior of light or electromagnetic radiations, polymer thin films have been used. High refractive index (RI) nanoparticle-incorporated polymer thin films are usually made by combining high RI inorganic nanoscale structures with a transparent, accessible polymer matrix. Hybrid nanocomposites, which combine the various benefits of inorganic and polymer components, offer a wide range of fascinating possibilities for advanced optoelectronic production and optical engineering such as advanced display device encapsulants; microlens components for complementary metal oxide semiconductor image sensors; plastic lenses for eyeglasses; camera, pick-up, and projector lenses; superior performance modules for sophisticated display devices. The development of polymers with a high refractive index (n) during the last ten years is discussed in this review, which also emphasizes the design idea to raise n values and Abbe's number (v) of polymers. The physics of predictable and controllable refractive tailored films is presently comprehended. Film applications in unconventional fields are explored. An outlook for the science and technology of such types of 2D/3D nanomaterials integrated polymer thin films concludes the review. [ABSTRACT FROM AUTHOR]

CMOS image sensor (CIS) plays a crucial role in diverse optical applications by facilitating the capture of images in the visible and near-infrared spectra. The enhancement of image resolution in CIS by an increase in pixel density is becoming more significant and realizable with the recent progress of nanofabrication. However, as pixel size decreases towards the diffraction limit, there is an inevitable trade-off between the scale-down of pixel size and the enhancement of optical sensitivity. Recently, to overcome this, an entirely new concept of spectral sensing using a nanophotonic-based color router has been proposed. In this work, we present a metasurface-based spectral router to effectively split the spectrum from visible to near-infrared and redirect through the four optical channels to the targeted pixel surfaces. We optimize the metasurface that simultaneously controls the phases of the transmitted light of targeted spectra, i.e. red (R), green (G), blue (B), and near-infrared (NIR), which is the largest number of channels reported based on a single layered metasurface and has an optical efficiency that surpasses the efficiency of conventional color filter systems. [ABSTRACT FROM AUTHOR]

We explore the use of smartphones to decode data transmitted from LEDs to smartphone cameras in visible light communication (VLC) applied to indoor positioning applications. The LEDs—modified to enable rapid on-off keying—transmit identification codes or optically encoded location data imperceptible to human perception. Equipped with a camera, the smartphone employs a single framed image to detect the presence of the luminaires in the image, decode their transmitted identifiers or locations, and determine the smartphone's position and orientation relative to the luminaires. The camera captures and processes images continuously. The following fundamental issues are addressed in this research: (i) analyzing the camera parameters on smartphones that affect data decoding results; (ii) exploiting the rolling shutter effect of the CMOS image sensor to receive multiple bits of data encoded in the optical communication line with a single frame shot; (iii) advancing research in developing algorithms to process data from multiple LEDs simultaneously. We conduct experiments to evaluate and analyze feasibility, as well as the challenges of the design, through scenarios varying in distance, transmission frequency, and data length. [ABSTRACT FROM AUTHOR]

Full-color single-pixel imaging aims to restore chromatic images using a single detector element, such as a photodiode or a single-pixel camera. However, image quality is inevitably compromised at low sampling rates due to inefficient sampling methods or incomplete representation of spectrum information. To address these challenges, we meticulously consider the distribution of the image frequency spectrum and the correlation between multiple bands and make further improvements in sampling strategy and reconstruction methods. First, we propose a variable density random sampling strategy based on the exponential distribution to enhance image sampling efficiency. Second, we discover that in most cases, there exists a hyper-Laplacian distribution between spectral mixed images and monochromatic images. Building upon this observation, we designed a hyper-Laplacian prior and seamlessly integrated it into our reconstruction method to enhance the performance of full-color images. Experimental results demonstrate that our method significantly improves the quality of reconstructed full-color images compared to state-of-the-art methods. [ABSTRACT FROM AUTHOR]

The traditional public art education model has many drawbacks. After all, this teaching model is the most common teaching model. Most colleges and universities still rely on the traditional teaching mode. This teaching mode is not attractive, boring, and low cost, so the popularity rate is high. The digital interactive design with multimedia courseware as the main body has played a great role in promoting the teaching of public art education in colleges and universities. In this paper, when teachers use multimedia courseware for teaching, because the computer cannot process physical signals, part of the hardware is a converter that converts physical signals such as light and pictures received by the CMOS sensor into digital signals and inputs them to digital signals and analog signals. Through the converter, the two-way transmission of teacher and student information in the teaching process of public art majors from the perspective of diversified public art was realized. At the same time, the information elements of sound, image and text were integrated into the interactive works of public art majors from the perspective of diverse public art, so as to stimulate students' interest in public art learning. Combined with the application of CMOS image sensor technology in diversified public art teaching, a questionnaire survey was conducted to explore the satisfaction of students in public art education and teaching of colleges and universities by CMOS image sensor technology, 50% of the students agreed with the proposal in this article. In this paper, the diversified public art teaching based on CMOS image sensor technology was derived outside the classroom, and the teaching was related to students' life, so as to improve the artistic atmosphere of the campus and truly improve the teaching effect of public art education in colleges and universities. [ABSTRACT FROM AUTHOR]

High-energy radiation is known to potentially impact the optical performance of silicon-based sensors adversely. Nevertheless, a proper characterization and quantification of possible spectral response degradation effects due to UV stress is technically challenging. On one hand, typical illumination methods via UV lamps provide a poorly defined energy spectrum. On the other hand, a standardized measurement methodology is also missing. This work provides an approach where well-defined energy spectrum UV stress conditions are guaranteed via a customized optical set up, including a laser driven light source, a monochromator, and a non-solarizing optical fiber. The test methodology proposed here allows performing a controlled UV stress between 200 nm and 400 nm with well-defined energy conditions and offers a quantitative overview of the impact on the optical performance in CMOS-based photodiodes, along a wavelength range from 200 to 1100 nm and 1 nm step. This is of great importance for the characterization and development of new sensors with a high and stable UV spectral response, as well as for implementation of practical applications such as UV light sensing and UV-based sterilization. [ABSTRACT FROM AUTHOR]

The synergistic effects on the 0.18 µm PPD CISs induced by neutron displacement damage and gamma ionization damage are investigated. The typical characterizations of the CISs induced by the neutron displacement damage and gamma ionization damage are presented separately. The CISs are irradiated by reactor neutron beams up to 1 × 1011 n/cm2 (1 MeV neutron equivalent fluence) and 60Co γ-rays up to the total ionizing dose level of 200 krad(Si) with different sequential order. The experimental results show that the mean dark signal increase in the CISs induced by reactor neutron radiation has not been influenced by previous 60Co γ-ray radiation. However, the mean dark signal increase in the CISs induced by 60Co γ-ray radiation has been remarkably influenced by previous reactor neutron radiation. The synergistic effects on the PPD CISs are discussed by combining the experimental results and the TCAD simulation results of radiation damage. [ABSTRACT FROM AUTHOR]

An automated system for acquiring microscopic-resolution radiographic images of biological samples was developed. Mass-produced, low-cost, and easily automated components were used, such as Commercial-Off-The-Self CMOS image sensors (CIS), stepper motors, and control boards based on Arduino and RaspberryPi. System configuration, imaging protocols, and Image processing (filtering and stitching) were defined to obtain high-resolution images and for successful computational image reconstruction. Radiographic images were obtained for animal samples including the widely used animal models zebrafish (Danio rerio) and the fruit-fly (Drosophila melanogaster), as well as other small animal samples. The use of phosphotungstic acid (PTA) as a contrast agent was also studied. Radiographic images with resolutions of up to (7±0.6)μm were obtained, making this system comparable to commercial ones. This work constitutes a starting point for the development of more complex systems such as X-ray attenuation micro-tomography systems based on low-cost off-the-shelf technology. It will also bring the possibility to expand the studies that can be carried out with small animal models at many institutions (mostly those working on tight budgets), particularly those on the effects of ionizing radiation and absorption of heavy metal contaminants in animal tissues. [ABSTRACT FROM AUTHOR]

The text discusses various new products in the fields of atomic force microscopy (AFM), scanning electron microscopy (SEM), fluorescence microscopy, mineral exploration, and image analysis. It mentions NuNano's SPARK range of conductive AFM probes, Kleindiek Nanotechnik's LT 14030 substage for SEM, FIB, and UHV applications, Teledyne's scientific imaging and machine vision solutions, MicroXRF's game-changing mineral exploration technology, Excelitas Technologies' X- Cite XYLIS 11 Broad Spectrum LED Illumination System, and Andor's Imaris 10.1 with AI segmentation tools. The article then focuses on four specific products: Imaris Al pixel classifier for fluorescent datasets, Livecyte Neurite Outgrowth assay for studying neuronal networks, Retiga E9 camera for low-light imaging, and DP75 digital microscope camera for brightfield and fluorescence imaging. It also mentions the NanoScan SP800 nanopositioning sample scanner for high-accuracy positioning. [Extracted from the article]

The text includes several research briefs and updates in the field of entomology. One study focuses on the diversity of damselfly faecal bacterial assemblages. Another study examines the impact of introduced carrion-feeding flies on native species in the Galapagos Islands. A review explores the social behavior of earwigs and its implications for understanding the emergence of social life among insects. Additionally, there are articles on the evolution of a selfing syndrome in plants, the treatment of injured ants by their nestmates, and the bioinspired development of imaging sensors for UV detection. The text also mentions entomologists advocating for insect science on Capitol Hill and the establishment of a new pilot section within the Entomological Society of America. [Extracted from the article]

With the electromagnetic environment becoming increasingly complex, it is crucial to address the risk posed by electromagnetic pulse, which critically impairs the performance and reliability of electronic systems based on complementary metal oxide semiconductor (CMOS) image sensors. In this context, research on the failure types of CMOS image sensors in a high-power electromagnetic environment, caused by strong electromagnetic pulses and the rapid evaluation method of interference immunity, has garnered significant interest. This paper conducts electromagnetic pulse simulation experiments on CMOS image sensors to first study their failure types, such as image abnormalities and functional interruption, and then identify the corresponding failure criteria. Furthermore, this study builds on the small sample test evaluation method to investigate the interference threshold of functional interruptions in CMOS image sensors by calculating the failure probability at different field strengths. The obtained data were combined with the Weibull distribution function for fitting, the results of which found the interference threshold to be at 40.4 kV/m. The findings of this study provide a basis for evaluating the survivability of CMOS image sensors and their associated reinforcement technology in high-power electromagnetic environments. [ABSTRACT FROM AUTHOR]

In the imaging process of Complementary Metal Oxide Semiconductor (CMOS) image sensor, noise is inevitably introduced at various stages. This effect is particularly serious when detecting weak signals, such as ultraviolet light. Through theoretical analysis of CMOS noise, we deduce that the main noise under illumination is non-uniformity noise by averaging the images to eliminate granular noise. Existing image denoising methods rely on simulated noise, which perform poorly when applied to real detectors. To address this issue, we establish a novel CMOS image dataset. Initially, we obtain the non-uniformity noise blocks from the CMOS imaging system designed in this paper. Then, we utilize a GAN network to augment the noise data. Next, we randomly combine these noise blocks with high-quality images from the DF2K dataset to form paired image datasets. In recent years, the development of various deep learning algorithms has significantly improved the effectiveness of image noise reduction compared to traditional algorithms. This paper combines convolutional neural network and proposes the MSR-Net denoising algorithm, which is based on the U-Net network and incorporates the Res2Net module as its main network structure. It provides features with different scale receptive fields and enhances image details. Additionally, to more accurately reflect the visual perceptual effects of the images, we propose a novel image evaluation metric, Uniform pixel outliers (UPO), making the image evaluation more adequate. Experiments were conducted on our proposed image dataset, results indicate that compared with similar noise reduction algorithms, this method performs better in both qualitative and quantitative aspects, effectively suppressing noise dominated by non-uniform noise.

In this work, an exhaustive analysis of the partial discharges that originate in the bubbles present in dielectric mineral oils is carried out. To achieve this, a low-cost, high-resolution CMOS image sensor is used. Partial discharge measurements using that image sensor are validated by a standard electrical detection system that uses a discharge capacitor. In order to accurately identify the images corresponding to partial discharges, a convolutional neural network is trained using a large set of images captured by the image sensor. An image classification model is also developed using deep learning with a convolutional network based on a TensorFlow and Keras model. The classification results of the experiments show that the accuracy achieved by our model is around 95% on the validation set and 82% on the test set. As a result of this work, a non-destructive diagnosis method has been developed that is based on the use of an image sensor and the design of a convolutional neural network. This approach allows us to obtain information about the state of mineral oils before breakdown occurs, providing a valuable tool for the evaluation and maintenance of these dielectric oils. [ABSTRACT FROM AUTHOR]

The last two decades have witnessed a dramatic increase in research on low‐dimensional material with exceptional optoelectronic properties. While low‐dimensional materials offer exciting new opportunities for imaging, their integration in practical applications has been slow. In fact, most existing reports are based on single‐pixel devices that cannot rival the quantity and quality of information provided by massively parallelized mega‐pixel imagers based on complementary metal‐oxide semiconductor (CMOS) readout electronics. The first goal of this review is to present new opportunities in producing high‐resolution cameras using these new materials. New photodetection methods and materials in the field are presented, and the challenges involved in their integration on CMOS chips for making high‐resolution cameras are discussed. Practical approaches are then presented to address these challenges and methods to integrate low‐dimensional material on CMOS. It is also shown that such integrations could be used for ultra‐low noise and massively parallel testing of new material and devices. The second goal of this review is to present the colossal untapped potential of low‐dimensional material in enabling the next‐generation of low‐cost and high‐performance cameras. It is proposed that low‐dimensional materials have the natural ability to create excellent bio‐inspired artificial imaging systems with unique features such as in‐pixel computing, multi‐band imaging, and curved retinas. [ABSTRACT FROM AUTHOR]

Single-image super-resolution (SISR) techniques have found wide applications in semiconductor defect inspection. Enhancing image resolution to improve inspection sensitivity and accuracy holds great significance. A novel SISR algorithm, called cross-convolutional residual network (CCRN), is proposed in this study. CCRN comprises a cross-convolutional module (CCM), which incorporates a cross-sharing mechanism that facilitates the fusion of features from different stages, enabling the extraction of more information from the image. Moreover, a global residual aggregation structure (GRA) is introduced. GRA captures and transfers different levels of residual features acquired from learning each CCM to the reconstruction layer. Experimental results demonstrate that the proposed SR algorithm outperforms existing state-of-the-art SR algorithms in terms of both visual and quantitative metrics when applied to optical, SEM, and TEM images of microfluidic chips, CMOS image sensors, and quantum dots, respectively. Additionally, CCRN significantly improves the accuracy of defect classification and inspection of unpatterned wafers, as evaluated using the WM-811K dataset. Notably, an increase in local defection testing accuracy from 79.00% to 89.00% and an improvement in classification accuracy from 93.69% to 96.06% are achieved. These findings underscore the potential applications of the proposed algorithm in improving semiconductor defect inspection and classification accuracies. [ABSTRACT FROM AUTHOR]

With the rise of autonomous driving technology, concerns over the safety of AI-based systems have increased, particularly regarding their effect on human life and infrastructure. The complexity and unpredictable nature of AI-enabled software functions have disrupted traditional safety evaluation methods. In such a scenario, the quality control methods used at the manufacturing environments of sensors used for deploying AI-based perception functions need to be coupled with the downstream functions. This study focuses on investigating the impact of a specific production-related defect called blemish, which is caused by debris on image sensors of camera modules. The research aims to answer two fundamental questions: 1) How can blemish artifacts be mathematically modeled, and what is the process for developing a suitable dataset that incorporates this defect? 2) How can the influence of blemish artifacts on performance of object detection models be traced back to define quality requirements of the camera modules? This work takes a novel perspective by shifting the focus from improving model resilience to improving hardware quality camera modules by studying the effects of manufacturing defects on downstream functions. This research seeks to establish a framework to derive quality targets for front camera module manufacturing which can be extended to other sensors for similar applications. [ABSTRACT FROM AUTHOR]

Significance: We present a motion-resistant three-wavelength spatial frequency domain imaging (SFDI) system with ambient light suppression using an 8-tap complementary metal-oxide semiconductor (CMOS) image sensor (CIS) developed at Shizuoka University. The system addresses limitations in conventional SFDI systems, enabling reliable measurements in challenging imaging scenarios that are closer to real-world conditions. Aim: Our study demonstrates a three-wavelength SFDI system based on an 8-tap CIS. We demonstrate and evaluate the system's capability of mitigating motion artifacts and ambient light bias through tissue phantom reflectance experiments and in vivo volar forearm experiments. Approach: We incorporated the Hilbert transform to reduce the required number of projected patterns per wavelength from three to two per spatial frequency. The 8-tap image sensor has eight charge storage diodes per pixel; therefore, simultaneous image acquisition of eight images based on multi-exposure is possible. Taking advantage of this feature, the sensor simultaneously acquires images for planar illumination, sinusoidal pattern projection at three wavelengths, and ambient light. The ambient light bias is eliminated by subtracting the ambient light image from the others. Motion artifacts are suppressed by reducing the exposure and projection time for each pattern while maintaining sufficient signal levels by repeating the exposure. The system is compared to a conventional SFDI system in tissue phantom experiments and then in vivo measurements of human volar forearms. Results: The 8-tap image sensor-based SFDI system achieved an acquisition rate of 9.4 frame sets per second, with three repeated exposures during each accumulation period. The diffuse reflectance maps of three different tissue phantoms using the conventional SFDI system and the 8-tap image sensor-based SFDI system showed good agreement except for high scattering phantoms. For the in vivo volar forearm measurements, our system successfully measured total hemoglobin concentration, tissue oxygen saturation, and reduced scattering coefficient maps of the subject during motion (16.5 cm/s) and under ambient light (28.9 lx), exhibiting fewer motion artifacts compared with the conventional SFDI. Conclusions: We demonstrated the potential for motion-resistant three-wavelength SFDI system with ambient light suppression using an 8-tap CIS. [ABSTRACT FROM AUTHOR]

This paper presents an adderless feed-forward incremental Δ Σ (I Δ Σ ) with asynchronous SAR (ASAR) that removes the need for in-column calibration by using global references, eliminates an additional summing amplifier and reduces the conversion time by using a multi-bit ASAR quantizer. The proposed I Δ Σ ADC is designed in 40 nm CMOS technology and is laid out compactly in a 5 μ m × 466 μ m column. According to post-layout simulations, the ADC achieves an input-referred noise of 85 μ V rms , a conversion time of 3.2 μ s (with DCDS) and a power consumption of 230 μ W. This results in a Walden FoM W of 234 fJ/conv.step and a FoM A = FoM W × A ADC of 0.54 fJ · mm 2 /conv.step, which demonstrates the feasibility of using the proposed architecture in CMOS image sensors. [ABSTRACT FROM AUTHOR]

This paper presents a new implementation of the rank-order filter, which is established on a parallel-operated array of single-slope (SS) analog-to-digital converters (ADCs). The SS ADCs use an "on-the-ramp processing" technique, i.e., filtration is performed along with analog-to-digital conversion, so the final states of the converters represent a filtered image. A proof-of-concept 64 × 64 array of SS ADCs, integrated with MOS photogates, was fabricated using a standard 180 nm CMOS process. The measurement results demonstrate the full functionality of the novel filter concept, with image acquisition in both single-sampling and correlated-double-sampling (CDS) modes (CDS is digitally performed using ADCs). The experimental, massively parallel rank-order filter can process 650 frames per second with a power consumption of 4.81 mW. [ABSTRACT FROM AUTHOR]

Radiation-induced damage and instabilities in back-illuminated silicon detectors have proved to be challenging in multiple NASA and commercial applications. In this paper, we develop a model of detector quantum efficiency (QE) as a function of Si–SiO2 interface and oxide trap densities to analyze the performance of silicon detectors and explore the requirements for stable, radiation-hardened surface passivation. By analyzing QE data acquired before, during, and after, exposure to damaging UV radiation, we explore the physical and chemical mechanisms underlying UV-induced surface damage, variable surface charge, QE, and stability in ion-implanted and delta-doped detectors. Delta-doped CCD and CMOS image sensors are shown to be uniquely hardened against surface damage caused by ionizing radiation, enabling the stability and photometric accuracy required by NASA for exoplanet science and time domain astronomy. [ABSTRACT FROM AUTHOR]

This paper introduces a new design of silicon nanowire (Si NW) phototransistor (PT) arrays conceived explicitly for improved CMOS image sensor performance, and comprehensive numerical investigations clarify the characteristics of the proposed devices. Each unit within this array architecture features a top-layer vertical Si NW optimized for the maximal absorption of incoming light across the visible spectrum. This absorbed light generates carriers, efficiently injected into the emitter–base junction of an underlying npn bipolar junction transistor (BJT). This process induces proficient amplification of the output collector current. By meticulously adjusting the diameters of the NWs, the PTs are tailored to exhibit distinct absorption characteristics, thus delineating the visible spectrum's blue, green, and red regions. This specialization ensures enriched color fidelity, a sought-after trait in imaging devices. Notably, the synergetic combination of the Si NW and the BJT augments the electrical response under illumination, boasting a quantum efficiency exceeding 10. In addition, by refining parameters like the height of the NW and gradient doping depth, the proposed PTs deliver enhanced color purity and amplified output currents. [ABSTRACT FROM AUTHOR]

Self-supervised learning (SSL) has significantly bridged the gap between supervised and unsupervised learning in computer vision tasks and shown impressive success in the field of remote sensing (RS). However, these methods have primarily focused on single-modal RS data, which may have limitations in capturing the diversity of information in complex scenes. In this paper, we propose the Asymmetric Attention Fusion (AAF) framework to explore the potential of multi-modal representation learning compared to two simpler fusion methods: early fusion and late fusion. Given that data from active sensors (e.g., digital surface models and light detection and ranging) is often noisier and less informative than optical images, the AAF is designed with an asymmetric attention mechanism within a two-stream encoder, applied at each encoder stage. Additionally, we introduce a Transfer Gate module to select more informative features from the fused representations, enhancing performance in downstream tasks. Our comparative analyses on the ISPRS Potsdam datasets, focusing on scene classification and segmentation tasks, demonstrate significant performance enhancements with AAF compared to baseline methods. The proposed approach achieves an improvement of over 7% in all metrics compared to randomly initialized methods for both tasks. Furthermore, when compared to early fusion and late fusion methods, AAF consistently outperforms in achieving superior improvements. These results underscore the effectiveness of AAF in leveraging the strengths of multi-modal RS data for SSL, opening doors for more sophisticated and nuanced RS analysis. [ABSTRACT FROM AUTHOR]

We present a 320 × 240 CMOS image sensor (CIS) using the proposed hybrid-correlated multiple sampling (HMS) technique with an adaptive dual-gain analog-to-digital converter (ADC). The proposed HMS improves the noise characteristics under low illumination by adjusting the ADC gain according to the incident light on the pixels. Depending on whether it is less than or greater than 1/4 of the full output voltage range from pixels, either correlated multiple sampling or conventional-correlated double sampling (CDS) is used with different slopes of the ramping signals. The proposed CIS achieves 11-bit resolution of the ADC using an up-down counter that controls the LSB depending on the ramping signals used. The sensor was fabricated using a 0.11 μm CIS process, and the total chip area was 2.55 mm × 4.3 mm. Compared to the conventional CDS, the measurement results showed that the maximum dark random noise was reduced by 26.7% with the proposed HMS, and the maximum figure of merit was improved by 49.1%. The total power consumption was 5.1 mW at 19 frames per second with analog, pixel, and digital supply voltages of 3.3 V, 3.3 V, and 1.5 V, respectively. [ABSTRACT FROM AUTHOR]

This paper presents an electron multiplication charge coupled device (EMCCD) based on capacitive deep trench isolation (CDTI) and developed using complementary metal oxide semiconductor (CMOS) technology. The CDTI transfer register offers a charge transfer inefficiency lower than 10 − 4 and a low dark current o 0.11 nA / cm 2 at room temperature. In this work, the timing diagram is adapted to use this CDTI transfer register in an electron multiplication mode. The results highlight some limitations of this device in such an EM configuration: for instance, an unexpected increase in the dark current is observed. A design modification is then proposed to overcome these limitations and rely on the addition of an electrode on the top of the register. Thus, this new device preserves the good transfer performance of the register while adding an electron multiplication function. Technology computer-aided design (TCAD) simulations in 2D and 3D are performed with this new design and reveal a very promising structure. [ABSTRACT FROM AUTHOR]

We introduce a compact voltage-domain global shutter CMOS image sensor for a wide range of applications including consumer, IoT, and industrial applications. With 0.5 MP and 2.79 µm pixels packed in a die size of only 2.3 mm × 2.8 mm, the sensor achieves more than 92% quantum efficiency (QE) in the visible wavelength and more than 36% at near-infrared (940 nm) all while drawing a mere 20 mW at a 10-bit, 30-frame-per-second operational mode. In this article, we focus on the architecture of the sensor and the design challenges encountered to fit all the necessary circuitry in such a limited footprint. Moreover, we detail the new solutions we have developed to meet the demanding specifications of low-power operation and high dynamic range (HDR). [ABSTRACT FROM AUTHOR]