We introduce a novel low-power imaging system capable of multispectral ultraviolet (UV) imaging with the ability to distinguish between different UV wavelengths. This advancement is achieved by enhancing a three-layer vertically stacked photodiode (3T APS) complementary metal-oxide-semiconductor (CMOS) image sensor with specially manufactured and tuned perovskite nanocrystals (PNCs), effectively extending the sensor’s multi-channel quantum efficiency across the UVB and UVA range. Our imaging system includes all necessary peripherals and circuits. Experimental results demonstrate that the PNC-enhanced sensor can precisely differentiate 11 distinct UV wavelengths between 300 nm and 400 nm, a level of detail unachievable with the unmodified sensor. This technology offers substantial potential for industrial and clinical applications, including the in-vitro detection of multiple biomarkers with subtly different UV fluorescence emission spectra.

We present the design, fabrication, and optical validation of a single-chip multispectral imaging sensor spanning 400 nm to 1050 nm. The sensor integrates vertically stacked photodiodes with pixelated spectral filters to capture 12 spectral bands—three in the visible spectrum and nine in the near-infrared (NIR) spectrum. This enables simultaneous visualization of both tumor-targeted and lymph node-mapping probes using the same NIR excitation source. The system’s performance was validated through optical experiments, demonstrating accurate spectral differentiation between indocyanine green (ICG) and the folate-targeted probe Cytalux. This multispectral imaging approach addresses the limitations of current imaging systems, which are restricted to single-probe visualization, offering a powerful tool for enhancing cancer surgery outcomes.

We present a single-chip imaging sensor capable of simultaneous ultraviolet (UV), visible (VIS), and near-infrared (NIR) imaging. The system integrates a checkerboard-patterned multispectral pixelated filter array with a three-layer stacked photodiode architecture, achieving six distinct spectral bands. Each photodiode layer is optimized for specific wavelengths, leveraging the wavelength-dependent absorption properties of silicon. With a power consumption of 250 mW and nearly 100% transmission in both UV and NIR spectra, the platform is optimized for intraoperative use without disrupting the surgical workflow. Clinical data from 33 patients with breast cancer demonstrated a positive predictive value of 100% for detecting primary tumors based on UV autofluorescence. These results highlight the platform’s potential for enhancing cancer detection in real-time surgical settings.

Despite tremendous developments in preoperative imaging that have enabled physicians to identify cancers with remarkable precision, limited options for intraoperative imaging have left many surgeons ill-equipped to locate tumors in the operating room. Near-infrared fluorescence image-guided surgery has offered to use near-infrared fluorescent dyes and near-infrared sensitive cameras to highlight diseased tissue, but state-of-the-art imaging systems have been unable to provide both the single sensor architecture and the high dynamic range required to facilitate precise surgical procedures under operating room illumination. In seeking a solution, we have monolithically integrated an array of forward-biased photodiodes and an array of interference filters to provide a logarithmic photoresponse across four spectral channels. The resulting single-chip snapshot multispectral imaging system provides an instantaneous dynamic range of >120 dB and a maximum signal-to-noise ratio of ∼56 dB across three color channels and one near-infrared channel. Capable of detecting less than 50 nM of the clinically-relevant fluorescent dye indocyanine green, this image sensor offers the high performance required for real-world surgical application.

Near-infrared fluorescence image-guided surgery relies on an interdisciplinary community to develop near-infrared fluorescent markers and near-infrared sensitive cameras capable of mapping relevant structures during surgical procedures. As biochemists pursue a new generation of near-infrared fluorophores aimed at surgical oncology and other applications, optoelectronic engineers developing near-infrared imagers have been slow to adopt architectural improvements that will enhance outcomes in existing operations and to document optoelectronic characteristics that are needed to predict endpoints for new procedures. Here we present a single-chip snapshot multispectral imaging system that integrates arrays of bandpass optical filters and six-transistor backside-illuminated pixels to provide RGB-NIR images with low read noise (3.47 e−) and high dynamic range (81 dB). This imaging system is being used in clinical studies for sentinel lymph node mapping during breast cancer surgery.

We have designed, fabricated, and tested a hexachromatic imager for near-infrared fluorescence image-guided surgery capable of simultaneously imaging three visible and near-infrared spectral channels. The sensor is comprised of 1280 by 720 pixels yielding a 48 dB signal-to-noise-ratio and achieving a minimum indocyanine green concentration detectability of 5 nM. The imaging sensor combines the vertically stacked photodiode technology and an array of pixelated spectral interference filters in a single-chip single-snapshot architecture yielding high sensitivity and clinical translation.

We have designed, fabricated, and tested a hexachromatic imager for near-infrared fluorescence image-guided surgery capable of simultaneously imaging three visible and near-infrared spectral channels. The sensor is comprised of 1280 by 720 pixels yielding a 48 dB signal-to-noise-ratio and achieving a minimum indocyanine green concentration detectability of 5 nM. The imaging sensor combines the vertically stacked photodiode technology and an array of pixelated spectral interference filters in a single-chip single-snapshot architecture yielding high sensitivity and clinical translation.

We have designed, fabricated, and tested a multi-spectral imager for near-infrared fluorescence image-guided surgery capable of simultaneously imaging both color and near-infrared fluorescence information with high sensitivity at 40 frames per second. The imaging sensor is composed of 1600 by 1200 imaging elements covered by pixelated spectral interference filters. The imaging sensor was successfully used in a preclinical study to assess and compare altered dynamic arterial perfusion in a murine model.

We have designed, fabricated, and tested a multi-spectral imager for near-infrared fluorescence image-guided surgery capable of simultaneously imaging both color and near-infrared fluorescence information with high sensitivity at 40 frames per second. The imaging sensor is composed of 1600 by 1200 imaging elements covered by pixelated spectral interference filters. The imaging sensor was successfully used in a preclinical study to assess and compare altered dynamic arterial perfusion in a murine model.

A 110 × 64 pixel CMOS image sensor integrated with pixelated spectral interference filters is used for image guided surgery. The sensor operates with short exposure times for capturing visible light using blue, green, and red pixelated interference filters, and long exposure time for capturing near-infrared fluorescence with a co-located, pixelated NIR filter. The sensor was used to successfully detect the fluorescence of ICG accumulation in sentinel lymph node on patients with breast cancer.

Near infra-red (NIR) fluorescence imaging offers high sensitivity and specificity for cancer detection and tumor margin localization. In this paper, a compact and wearable NIR fluorescence imaging system (FIS) for image guided surgery is presented. The proposed FIS captures 27 frames per second of both NIR and visible spectrum data, allowing for minimum detection of 10nM of ICG concentration. The design tradeoffs of the complete system are carefully analyzed. The performance of the proposed FIS is evaluated under both sensitivity test and experimental mouse study. The imaging system is currently used in clinical trials for imaging sentinel lymph nodes in breast cancer and melanoma patients.

This demonstration presents a compact and wearable NIR fluorescence imaging system (FIS) for image guided surgery. The proposed FIS captures 27 frames per second of both NIR and visible spectrum data, allowing for minimum detection of 10nM of ICG concentration. The imaging system is currently used in clinical trials for imaging sentinel lymph nodes in breast cancer and melanoma patients.

We have designed, fabricated, and tested a division-of-focal-plane polarimeter capable of simultaneously imaging both spectral and polarization information at 30 frames per second. The imaging sensor, composed of 1300 by 800 imaging elements, each containing three vertically stacked photodetectors, is covered by pixelated nanowire polarization filters at four different orientations offset by 45°. The polarimeter has a dynamic range of 62 dB and captures intensity, angle, and degree of linear polarization in three visible spectrum bands while consuming 700 mW of power.

Summary form only given. We have designed, fabricated, and tested a division-of-focal-plane polarimeter capable of simultaneously imaging both spectral and polarization information at 30 frames per second. The imaging sensor, composed of 1300 by 800 imaging elements, each containing three vertically stacked photodetectors, is covered by pixelated nanowire polarization filters at four different orientations offset by 45°. The polarimeter has a dynamic range of 62 dB and captures intensity, angle, and degree of linear polarization in three visible spectrum bands while consuming 700 mW of power.

A 220 by 128 current mode imaging sensor with polarization sensitivity is used to image intrinsic neural activity in vivo from the antenna lobe of a locust. The polarization sensitivity is achieved via post-CMOS fabrication deposition of pixelated aluminum nanowire polarization filters at four different orientations offset by 45 degrees. The measured change in polarization response from the neural cells baseline for hexanol is 0.38%, for octanol is 0.15%, and for the combined odor is 0.45%.

Biologically inspired solutions for modern-day sensory systems promise to deliver both higher capacity and faster, more efficient processing of information than current computational approaches. Many animals are able to perform remarkable sensing tasks despite only being able to process what would be considered modest data rates and bandwidths. The key biological innovations revolve around dedicated filter designs. By sacrificing some flexibility, specifically matched and hard-wired sensory systems, designed primarily for single roles, provide a blueprint for data and task-specific efficiency. In this paper, we examine several animal visual systems designed to use the polarization of light in spatial imaging. We investigate some implications for artificial optical processing based on models of polarization image processing in fiddler crabs, cuttlefish, octopus, and mantis shrimp.

In this paper, we present recent work on bioinspired polarization imaging sensors and their applications in biomedicine. In particular, we focus on three different aspects of these sensors. First, we describe the electro-optical challenges in realizing a bioinspired polarization imager, and in particular, we provide a detailed description of a recent low-power complementary metal-oxide-semiconductor (CMOS) polarization imager. Second, we focus on signal processing algorithms tailored for this new class of bioinspired polarization imaging sensors, such as calibration and interpolation. Third, the emergence of these sensors has enabled rapid progress in characterizing polarization signals and environmental parameters in nature, as well as several biomedical areas, such as label-free optical neural recording, dynamic tissue strength analysis, and early diagnosis of flat cancerous lesions in a murine colorectal tumor model. We highlight results obtained from these three areas and discuss future applications for these sensors.

A current-mode CMOS imaging sensor is presented in this paper. The read-out transistor in the photo pixel operates in velocity saturation regime and allows for high linearity between integrated photo charges and output drain current. The column parallel read-out circuitry implements a novel current conveyor with a feedback mechanism which improves matching of the output currents across the imaging array. Correlated double sampling (CDS) is performed on-chip in order to improve noise characteristics of the imager. A prototype of the proposed imaging sensor was fabricated in 0.18μm triple well CMOS process. The sensor operation and measurements are presented.

Recent advancements in nanotechnology have allowed for the emergence of integrated polarization imaging sensors. These sensors capture polarization properties of the optical field in high resolution and at every imaging frame. Signal processing algorithms for polarization imaging sensors are at its infancy and mandate new research in order to take advantage of the capabilities offered by this class of sensors. In this paper, we present gradient based interpolation algorithm for polarization sensors and evaluate its performance against a group of previously published interpolation methods.

In this paper we present a procedure for fabricating an array of micropolarization filter array via an optimized interference lithography and microfabrication procedure. The filter array is composed of two linear polarization filters offset by 45 degrees with pixel pitch of 18 microns. The individual polarization filters are composed of aluminum nanowires with 140 nm pitch, 140 nm height and 70 nm width.

Magnetologic circuits are digital logic circuits constructed using magnetic tunnel junction (MTJ) devices. These devices are non-volatile, robust, and scale favorably with process dimensions. Several approaches exist for building magnetologic circuits. We are investigating current-mode magnetologic circuits as a viable option. Current-mode circuits avoid charging/ discharging load capacitances and can be used to program a downstream device. Noise in a current-mode read circuit can affect the ability to correctly distinguish logic states in an MTJ. In this paper, we present a noise analysis of a current-mode read circuit or current conveyor. We derive analytical noise equations and verify them via simulation.

In this paper we present both theoretical modeling and experimental data on the noise performance of two different division of focal plane polarization imaging sensors. Theoretical estimations of the Stokes parameter signal-to-noise ratios for CCD polarization imaging sensors with both 4-polarizer and 2-polarizer micropolarization filter arrays are derived. The theoretical derivation is verified with measurements from an integrated polarization imaging sensor composed of CCD imaging array and aluminum nanowire polarization filters.

Polarization is a fundamental property of light for which humans have no innate detector. Numerous sensors have been devised to capture this property of light. Of these types of sensors, division of focal plane polarimeters allow for both high resolution and real-time capture of the angle and degree of polarization. This paper details a formal system of measurements designed to categorize the optical performance of one such sensor. Specifically, this paper details methods for evaluating the accuracy of both the degree and angle of polarization as functions of intensity, wavelength, and camera orientation for a division of focal plane polarimeter.

We will demonstrate the performance of an integrated CCD polarization image sensor. The polarization image sensor combines CCD imaging technology with aluminum nanowire optical filters monolithically at the focal plane. The image sensor computes polarization parameters of partially polarized light and presents this information to the end user in false color representation. The image sensor will demonstrate its capabilities in discriminating different materials based on the polarization signatures. The image sensor has a dynamic range of 65dB, signal-to-noise ratio of 60dB and power consumption of 280mW at 40 frames per second.

We present a novel polarization image sensor by monolithically integrating aluminum nanowire optical filters with CCD imaging array. The CCD polarization image sensor is composed of 1000 by 1000 imaging elements with 7.4μm pixel pitch. The image sensor has a dynamic range of 65dB and signal-to-noise ratio of 60dB. The CCD array is covered with an array of pixel-pitch matched nanowire polarization filters with four different orientations offset by 45°. Raw polarization data is presented to a DSP board at 40 frames per second, where degree and angle of polarization is computed. The final polarization results are presented in false color representation.

Linear current mode CMOS image sensor that performs spatial convolution during pixel readout using low power analog circuitry is presented. The image sensor has 128 by 109 pixel array, digital scanning registers, pixel selection circuitry, and digitally programmable analog processing unit. An intensity image in parallel with two convolved images is provided outside the chip at 60 frames per second. The image sensor was fabricated in 0.5 micron 3M2P process. The sensor operation and performance measurements are presented.

A micropolarization array composed of a dual layer nano-wire polarization filters is presented. The nano-wire polarization filters are composed of 80 nm wide aluminum wires with 160 nm wire pitch. Two nano-wire polarization filters are separately patterned and etched with 6 micron square structures. The two layers are offset by 45 degrees and merged together to form the final filter. The extinction ratios of the filter are experimentally measured to be 150 and 1000 in the blue and red spectrum respectively.

A novel low power polarization image sensor is presented. This image sensor synergistically combines polymer polarization filters with a CMOS image sensor in order to compute the first three Stokes parameters at the focal plane. The carefully optimized microfabrication procedure for the pixel-pitch polymer polarization filters is described in detail in this paper. The imaging array is composed of 60 by 20 pixels and consumes 15mW at 30fps. A demo of the completed polarization image sensor will be given to illustrate how objects of similar luminescence can be discriminated based on their polarimetric properties.

A complete polarization image sensor composed of a 60 by 20 pixel array with on-chip analog processing and an integrated pixel-pitch polymer polarization filter is presented. The image sensor computes the first three Stokes parameters at the focal plane at 30 fps with 15 mW power consumption. The sensor is used to identify automatically material properties by computing the degree of polarization off chip.

A novel 1.5 transistors per pixel linear current mode active pixel sensor (APS) is presented. The photo pixel address switch is placed outside the pixel, effectively implementing 1.5 transistors per pixel using a sharing scheme of the read-out and reset transistor. The column FPN of 0.4% and SNR of 43dB is measured. The total power consumption is 5mW at 30fps. A theoretical framework for optimizing temporal and spatial noise is presented.

This paper describes a current-mode active pixel sensor (APS) for low supply voltage, low noise and high resolution/high speed imaging applications. The imager is designed in a standard 0.25μm 2.5V CMOS process. A transistor count of 1.5 per pixel is achieved through transistor sharing and floating diffusion (FD) based addressing. Highly linear current readout in velocity saturation, as well as triple sampling (TS), are used to reduce fixed pattern noise (FPN). Dynamic range (DR) is improved through FD presetting and boosting techniques, which allow the full-well capacity of photodiodes to be utilized without degrading readout linearity. Post-extraction simulation results on FPN and DR are presented, and compared favorably to a conventional 3-transistor pixel design.

A novel current mode active pixel sensor for high resolution imaging is presented. The photo pixel is composed of a photodiode and two transistors: reset and transconductance amplifier transistor. The switch transistor is moved outside the pixel, allowing for lower pixel pitch and increased linearity of the output photocurrent. The increased linearity of the image sensor has greatly reduced spatial variations across the image after correlated double sampling and the column fix pattern noise is 0.35% of the saturated current. A discussion on theoretical temporal noise limitations of this design is also presented.

This paper described a novel current-mode active pixel sensor (APS) imager. Conversion of photodiode voltage to output current is done using transistors operating in velocity saturation region. The high output impedance of this region makes it more suitable for current-sourcing operation than the linear region. The transistors also exhibit high linearity, allowing us to suppress fixed pattern noise (FPN) by correcting for both offset and gain variations among pixels. Experimental results on the fabricated 110times200 pixel array are presented. With conventional correlated double sampling (CDS), FPN is reduced from 3.8% to 0.85%. Further reduction requires compensation of gain variations, and results in a final FPN of 0.19%. A triple sampling approach is introduced to implement the described correction in hardware.

A novel focal plane imaging sensor capable of real time extraction of polarization information is presented. The imaging system consists of a photo array of 256 by 256 linear current mode active pixel sensors (APS). Analog processing circuitry is included at the focal plane for noise suppression and computation of the Stokes parameters. The imaging sensor was fabricated in 0.18mum process with 10mum pixel pitch and 75% fill factor. An array of micro polarizer is designed and fabricated separately and is mounted on top of the imaging array. Simulation results of the imaging sensor are presented

An architectural overview of an image sensor with general spatial processing capabilities on the focal plane is presented. The system has been fabricated on two separate tiers, implemented on silicon-on-insulator technology with vertical interconnect capabilities. One tier is dedicated to imaging, where photosensitivity and pixel fill have been optimized. The subsequent layers contain noise suppression and digitally controlled analog processing elements, where general spatial filtering is computed. The digitally controlled aspect of the processing unit allows generic receptive fields to be computed on read out. The image is convolved with four receptive fields in parallel. The chip provides parallel readout of the filtered results and the intensity image.

A thin film polarizer has been patterned and etched using reactive ion etching (RIE) in order to create 14 micron circular periodic structures. The polarization thin film has extinction ratio of 60dB in the blue and green visible spectrum and /spl sim/40db in the red spectrum. Various gas combinations for RIE has been explored and it has been experimentally determined that for a particular concentration of CF/sub 4/ and O/sub 2/ an optimum etching rate, in terms of speed and under-etching, is possible. Theoretical explanation for the optimum etching rate has been also presented. In addition, anisotropic etching with less then 0.5/spl mu/m under cutting has been achieved. Experimental results of the patterned structures under polarized light are presented.

We present a CMOS image sensor capable of both voltage- and current-mode operations. Each pixel on the imager has a single transistor acting as either source follower for voltage readout, or transconductor for current readout. The two modes share the same readout lines, but have their own correlated double sampling (CDS) units for noise suppression. We also propose a novel current-mode readout technique using a velocity-saturated short-channel transistor, which achieves high linearity. The 300/spl times/200 image array is a mixture of 3 types of pixels with identical photodiodes and access switches; while the readout transistors are sized for their designated mode of operation. This ensures a fair comparison on the performance of the different modes.

A 16/spl times/16 pixel pseudo general-purpose vision chip for spatiotemporal focal-plane processing is presented. The convolution of the image with programmable kernels are realized with area-efficient and real-time circuits. The chip's architecture allows the photoreceptor cells to be small and densely packed by performing all analog computations on the read-out, away from the array. The size, configuration and coefficients of the kernels can be varied on the fly. In addition to the raw intensity image, the chip outputs four processed images in parallel. The convolution is implemented with a digitally programmable analog processor, resulting in very low power consumption at high computation rates.