Select Parent Grandparent Teacher Kid at heart. Age of the child I gave this to:. Hours of Play:. Tell Us Where You Are:. Preview Your Review. Thank you. Your review has been submitted and will appear here shortly. Extra Content. Table of Contents Preface. Generation of Free Carriers in Semiconductors. Photoelectric Characteristics of Resistive Photodetectors. Photodetectors with P-N Junction.
Elements of the Theory of Random Processes. Internal Noise in Photodetectors. In combination with advanced multivariate techniques for data analysis, this technology have been used to study defects in both multicrystalline and monocrystalline wafers and solar cells. Some of the mapped defects have been linked to well known mechanisms that could previously only be studied by destructive and time consuming methods.
So far this technique has only been explored in research laboratories. The goal is however to be able to use this in line in solar cell processing. In this presentation it will also be discussed how this technology can be used to map degradation of outdoor solar panels. In this project we design and fabricate a hyperbolic metamaterials-based narrowband notch filter for the mid-wave infrared regime with an angle-of-incidence independent center-wavelength for TM polarized incident light.
To achieve angle of incidence independence, a subwavelength sized array of copper wires is inserted in a vertical orientation and permeates the three middle layers of the seven layer Bragg stack filter. Analysis using Maxwell- Garnett theory and full-wave electromagnetic modeling, and the fabrication progress to date are presented. Narrowband notch filters have applications in optical communications systems, and remote sensors such as hyperspectral and multi-spectral sensing and imaging.
Metasurfaces, nanophotonic arrays of phase shifting elements, hold promise for the miniaturization of a variety of bulk optical elements, most notably lenses and imaging systems. Owing to the flexibility with which their constituent elements may be engineered, metasurfaces allow for point-to-point polarization control on a subwavelength scale. For this reason, metasurfaces represent an exciting new platform for polarization optics as well. I will discuss how this functionality allows for a new perspective on diffractive optics which explicitly acknowledges the vectorial nature of light.
This perspective motivates a theory of unitary polarization gratings; I will derive a few key results concerning these gratings. I will discuss and demonstrate how this perspective allows for the design of metasurfaces with new polarization functionalities. I will describe how, through relatively simple optimization methods, a metasurface producing arbitrarily specified polarization states can be designed.
This functionality is equivalent to a traditional diffraction grating with individual waveplate optics on each order; here, all the necessary polarization optics can be integrated into a flat, ultrathin optical element.
Moreover, such a metasurface can be used in a reverse configuration as a parallel snapshot polarimeter with no need for additional polarization optics. I present a detailed experimental characterization of this device in the visible spectral region and a comparison of the performance of the metasurface to a commercially available rotating waveplate polarimeter. Finally, I will discuss the extension of these concepts to compact polarization imaging systems and will provide a broad outlook on metasurfaces in polarization optics, polarization sensing systems, and polarization instrumentation more generally.mixseller.ru/comment-acheter-plaquenil-online-livraison.php
Methods And Materials For Remote Sensing: Infrared Photo-detectors, Radiometers And Arrays
Fungal pathogens constitute the greatest economical concern to corn farmers; they result in yield losses, grain quality reduction and production of mycotoxins. Improvement of detection methods are imperative. This work aimed to examine corn fungal pathogens with HSI. Isolates of Fusarium spp. Images were acquired with a SisuChema short-wave infrared pushbroom imaging system in the spectral range — nm. Principal component analysis PCA , with various pre-processing methods, and multivariate curve resolution MCR were used to explore the data.
PCA with or without pre-processing, revealed chemical differences within and between fungal isolates. Differences were amplified with time. This is expected since fungi are mainly comprised of these constituents and as the mycelium grows and ages, there is a change in carbohydrate content or structure , moisture and protein. This was apparent in higher order components PCs and appeared as textured information.
Multispectral image - Wikipedia
In addition, these maps were textured illustrating the physical changes of the mycelium with time. These were due to the growing hyphae and possible spore formation. In addition, it is likely that these concentration maps indicated presence of mycotoxins.
Since hyperspectral imaging has been developed as a powerful technique in earth remote sensing, this technique continues being utilized in medical, biological, agricultural, and industrial areas. This technique is capable of providing radiometric measurements over contiguous spectral ranges for every pixel of an image. Thus, data from hyperspectral images contain two—dimensional spatial information and spectral information as well.
Our research group has been working on development of hyperspectral imaging technology for food quality and safety evaluation. For the detection of contaminants on broiler carcasses in poultry industry, real-time hyperspectral imaging system with line-scan platform has been developed and tested at processing line speed. In particular, hyperspectral imaging methods at microscopic level have been developed for food safety applications, because early and rapid detection of foodborne pathogen during food processing are crucial to protect foodborne illness and prevent outbreaks to the public.
In this presentation, the state-of-the-art hyperspectral microscope imaging HMI methods to identify and classify foodborne bacteria are reported.
More detail, research findings regarding development of HMI methods including immobilization of live bacterial samples on microscopic glass slide for HMI scan, dark-field illumination for scattering intensity from bacterial images at cellular level, acousto-optic tunable filters AOTF -based HMI image acquisition from live bacteria, HMI image processing and analysis at both spatial and spectral domains, development of classification models with deep-learning as well as various chemometric methods, and finally, early and rapid detection of foodborne pathogens with HMI technique for food industry applications are presented.
Uncooled doped-Si thermopiles for thermal land imaging applications Author s : Emily M.
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Barrentine; Ari D. Reid ; Sang Yoon ; Alicia T. Joseph Show Abstract. Sustained and enhanced land imaging is crucial for providing high-quality science data on change in land use, forest health, environment, and climate. Future thermal land imaging instruments operating in the micron band will provide essential information for furthering our hydrologic understanding at scales of human influence, and producing field-scale moisture information through accurate retrievals of evapotranspiration ET.
To address the need for cost-effective future thermal land imaging missions we are developing novel uncooled doped-silicon thermopile detectors, an extension of a detector design concept originally developed at NASA-Goddard for planetary science applications. These doped-Si thermopile detectors have the potential to offer superior performance in terms of sensitivity, speed, and customization, when compared to current commercial-off-the-shelf uncooled detector technologies.
Because cryocooler technology does not need to be fielded on the instrument, these and other uncooled detectors offer the benefit of greatly reduced instrument cost, mass, and power at the expense of some acceptable loss in detector sensitivity. We present the motivation for an uncooled thermal imaging instrument, our doped-Si thermopile detector concept, and performance expectations and comparisons.
We also provide an update on the current status of this detector technology development. Yung; Nathan A. Richard; David M. Harber ; John H. Lehman; Michelle S. Stephens Show Abstract. The linear array of radiometer elements is based on uncooled vanadium oxide VO x microbolometer pixel technology but with the addition of two elements: vertically aligned carbon nanotubes VACNTs and an electrical substitution heater.
In addition, each pixel has an electrical substitution heater which can be used to determine equivalent incident optical power when the device is non-illuminated. This device forms the basis of an absolute radiometer eliminating the need for an external reference e. Arafin ; H. Jung Show Abstract. Among several types of diode lasers, electricallypumped continuous-wave operating VCSELs seem to be the most attractive choice owing to their low-power consumption, inherent longitudinal single-mode emission, and simple electro-thermal wavelength tunability.
Single-mode low-power a few mWs VCSEL operating at room-temperature with reasonable tunability is essential for the sensing application. Given that the MWIR wavelength regime is eye-safe and has a low-loss atmospheric window, the development of next-generation MWIR laser sources is currently in high demand. A barrier to this concept is that the definition and measurement equipment of uniformity measurements often need to be very specific to the optical prescription of the unit under test.
Additionally, the resulting data are often a relativistic data set, assigned to an arbitrary reference, but not actually given an expression of uncertainty with a coverage factor. This paper discusses several optical measurement methods and numerical methods that can be used to quantify and express uniformity so that it has meaning to the optical systems that will be tested, and ultimately, that can be related to the Guide to the Expression of Uncertainty in Measurement GUM to provide an estimated uncertainty.
The resulting measurements can then be used to realize very accurate flat field image corrections and sensor characterizations. Long-wavelength infrared LWIR focal plane arrays FPAs needed for Earth Science imaging, spectral imaging, and sounding applications have always been among the most challenging in infrared photodetector technology due to the rigorous material growth, device design and fabrication demands.
Future small satellite missions will present even more challenges for LWIR FPAs, as operating temperature must be increased so that cooler and radiator volume, mass, and power can be reduced. To address this critical need, we are working on following three technologies. By combining the aforementioned technologies, this project seeks to demonstrate a cost-effective, high-performance LWIR FPA technology with significantly higher operating temperature and sensitivity than previously attainable, and with the flexibility to meet a variety of Earth Science TIR measurement needs, particularly the special requirements of small satellite missions.
These are required for applications in big science, security and biochemistry. SAPHIRA has been deployed as a wavefront sensor for adaptive optic systems in nine major telescopes and notably five devices control the four 8. The detector is baselined for time-domain astronomy vital for exoplanet spectroscopy and understanding the physics of active stellar objects. The three 30 metre class telescopes currently under construction and the three candidate space telescopes, HabEx, Luvoir and EZE will depend on noise-free infrared detectors at very low dark current.
Rapid prototyping of single-photon-sensitive backside-illuminated silicon avalanche photodiode arrays Author s : Kevin K. Ryu; K.
Leitz; Daniel R. Schuette; Brian F. Aull Show Abstract. APD arrays are fabricated on a custom silicon-on-insulator SOI wafer engineered with a built-in backside contact and passivation layer. The engineered APD substrate structure facilitates uniform APD substrate removal by selective etching at the die level after bump bonding.
The new integration process has the following advantages over wafer-level 3D integration: 1 reduced cost per development cycle since a dedicated full-wafer ROIC fabrication is not needed, 2 compatibility with existing ROICs that are in chip-format from previous fabrication runs, and 3 accelerated schedule.
Related Methods and Materials for Remote Sensing: Infrared Photo-Detectors, Radiometers and Arrays
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