- 标题
- 摘要
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- 实验方案
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Ultra-Broadband, High Speed, and High-Quantum-Efficiency Photodetectors Based on Black Phosphorus
摘要： Black phosphorus (BP), a narrow band gap semiconductor without out-of-plane dangling bonds, has shown promise for broadband and integrable photodetector applications. Simultaneously exhibiting high speed and high-efficiency operation, however, remains a critical challenge for current BP-based photodetectors. Here, we demonstrate a photodetector based on the BP-based van der Waals heterostructures. The developed photodetector enables broadband responses in the visible to mid-infrared range with external quantum efficiency (EQE) ranging from 20% to 52% at room temperature. These results together with noise measurements indicate the photodetector can detect light in the pico-watt range. Furthermore, the demonstrated BP detector has ultrafast rise (1.8 ns) and fall (1.68 ns) times, and its photoresponse exhibits reproducible switching behavior even under consecutive and rapid light intensity modulations (2100 cycles, 200 MHz), as indicated by the eye-diagram measurement. By leveraging these features, we show our BP heterostructures can be configured as a point-like detector in a scanning confocal microscopy, useful for mid-infrared imaging applications.
关键词： van der Waals heterostructures,mid-infrared imaging,Black phosphorus,high speed,broadband photoresponses,photodetector
更新于2025-09-11 14:15:04
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Principles and prospects for single-pixel imaging
摘要： Modern digital cameras employ silicon focal plane array (FPA) image sensors featuring millions of pixels. However, it is possible to make a camera that only needs one pixel. In these cameras a spatial light modulator, placed before or after the object to be imaged, applies a time-varying pattern and synchronized intensity measurements are made with a single-pixel detector. The principle of compressed sensing then allows an image to be generated. As the approach suits a wide a variety of detector technologies, images can be collected at wavelengths outside the reach of FPA technology or at high frame rates or in three dimensions. Promising applications include the visualization of hazardous gas leaks and 3D situation awareness for autonomous vehicles.
关键词： 3D imaging,computational imaging,spatial light modulator,compressed sensing,infrared imaging,single-pixel imaging,terahertz imaging
更新于2025-09-10 09:29:36
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[IEEE NAECON 2018 - IEEE National Aerospace and Electronics Conference - Dayton, OH, USA (2018.7.23-2018.7.26)] NAECON 2018 - IEEE National Aerospace and Electronics Conference - Towards fabrication of mid-IR FPAs with enhanced sensitivity and reduced dark current by using integration with microspherical arrays
摘要： It was demonstrated previously that the efficiency of light collection by individual pixels of mid-wave infrared (MWIR) focal plane arrays (FPAs) can be enhanced by using dielectric microspheres, which provide concentration of light with large angle-of-view. This approach allows miniaturizing photodetector mesas to reduce their thermal current that, in turn, helps increasing the operating temperature of FPAs. In this work, we develop a technology of parallel integration of thousands of microspheres with the pixels. We fabricated microhole arrays and used them as suction grippers for microspheres. It is shown that in large-scale arrays formed by microspheres with several tenths microns in diameter, the fabrication errors below ~1% can be obtained. The fabrication errors can be significantly reduced in arrays formed by larger (>100 microns) microspheres.
关键词： Thermal (uncooled) IR detectors,Imaging,Infrared imaging,Focal plane arrays,Photodetectors
更新于2025-09-09 09:28:46
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Utility of lacrimal caruncle infrared thermography when monitoring alterations in autonomic activity in healthy humans
摘要： Purpose Physiological markers that estimate sympathetic activation may be used to infer pain and stress in humans. To date, effective reproducible methods are invasive and pose an undesired risk to participants. Previous work in animal models has used infrared thermography to measure the temperature of the lacrimal caruncle region and may be a promising method for measuring stress and pain non-invasively. The current study aimed to determine whether this method is useful in humans. Methods Sixteen young healthy participants (age: 18–35) were recruited and underwent sympathetic activation using a cold pressor test (CPT) and a muscle chemoreflex (MCR), and completed a control trial. Throughout all trials, infrared thermographic imaging of the lacrimal caruncle, heart rate, heart rate variability, mean arterial blood pressure and pulse transit time were measured. Results Heart rate (MCR: 4 ± 3?bpm, CPT: 17 ± 4?bpm p < 0.01) and mean arterial pressure increased (MCR: 6 ± 2, CPT: 5 ± 2?mmHg, p < 0.01) and pulse transit time decreased (p = 0.03) with both sympathetic activation interventions. However, lacrimal caruncle temperature did not vary under any condition remaining at 35.2 ± 0.2?°C which was similar to baseline. Conclusions Our findings suggest infrared thermographic monitoring of eye temperature in humans does not reliably relate to sympathetic activation. This could be due to hemodynamic responses at the lacrimal caruncle that may be more complex than previously proposed with sympathetic activation. Alternatively, pulse transit time seems like a promising non-invasive measure of changes in sympathetic activation in humans.
关键词： Sympathetic nervous system activation,Muscle chemoreflex,Thermography,Muscle metaboreflex,Infrared imaging
更新于2025-09-09 09:28:46
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Total Variation Based Neural Network Regression for Nonuniformity Correction of Infrared Images
摘要： Many existing scene-adaptive nonuniformity correction (NUC) methods suffer from slow convergence rate together with ghosting effects. In this paper, an improved NUC algorithm based on total variation penalized neural network regression is presented. Our work mainly focuses on solving the overfitting problem in least mean square (LMS) regression of traditional neural network NUC methods, which is realized by employing a total variation penalty in the cost function and redesigning the processing architecture. Moreover, an adaptive gated learning rate is presented to further reduce the ghosting artifacts and guarantee fast convergence. The performance of the proposed algorithm is comprehensively investigated with artificially corrupted test sequences and real infrared image sequences, respectively. Experimental results show that the proposed algorithm can effectively accelerate the convergence speed, suppress ghosting artifacts, and promote correction precision.
关键词： total variation,neural network,infrared imaging,nonuniformity correction
更新于2025-09-04 15:30:14
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Forward projection matrix derivation through Monte-Carlo ray-tracing of KSTAR infra-red imaging video bolometer (IRVB)
摘要： The infrared imaging video bolometer (IRVB) as a foil bolometry technique can be an alternative solution to the conventional resistive bolometer due to its electro-magnetic immunity and 2D plasma profiles. The plasma profile of the IRVB cannot be directly derived from the foil images due to the difference between the foil pixel number and the plasma pixel number and the line integrated nature of the incident rays on the foil. So, it needs tomography such as the Phillips-Thikhonov algorithm. The projection matrix constructing the foil image from the plasma very directly influences the tomography. So, the projection matrix needs to be constructed precisely. For the technique calculating the precise projection matrix, a forward Monte-Carlo ray-tracing method is proposed here, and this technique can provide the detailed descriptions of the foil image. And it can give enhanced performance in the reconstructions of the plasmas with spatially localized power.
关键词： infrared imaging video bolometer,projection matrix,IRVB,foil bolometry,Monte-Carlo ray-tracing,plasma profile reconstruction
更新于2025-09-04 15:30:14