The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform
G S Agarwal - One of the best experts on this subject based on the ideXlab platform.
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temporal quantum noise reduction acquired by an electron multiplying Charge Coupled Device camera
Optics Express, 2020Co-Authors: G S AgarwalAbstract:Electron-multiplying Charge-Coupled-Device cameras (EMCCDs) have been used to observe quantum noise reductions in beams of light in the transverse spatial degree of freedom. For the quantum noise reduction in the temporal domain, ‘bucket detectors,’ usually composed of photodiodes with operational amplifiers, are used to register the intensity fluctuations in beams of light within the detectors’ bandwidth. Here, we report on measurements of the temporal quantum noise reduction in bright twin beams using an EMCCD camera. The four-wave mixing process in an atomic rubidium vapor cell is used to generate the bright twin beams of light. We observe ∼ 25% of temporal quantum noise reduction with respect to the shot-noise limit in images captured by the EMCCD camera. The temporal images captured by our technique are potentially important in obtaining dynamical information on evolving systems.
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temporal quantum noise reduction acquired by an electron multiplying Charge Coupled Device camera
arXiv: Optics, 2020Co-Authors: G S AgarwalAbstract:Electron-multiplying Charge-Coupled-Device cameras (EMCCDs) have been used to observe quantum noise reductions in beams of light in the transverse spatial degree of freedom. For the quantum noise reduction in the temporal domain, "bucket detectors," usually composed of photodiodes with operational amplifiers, are used to register the intensity fluctuations in beams of light within the bandwidth of the detectors. Spatial information, however, is inevitably washed off by the detector. In this paper, we report on measurements of the temporal quantum noise reduction in bright twin beams using an EMCCD camera. The four-wave mixing process in an atomic rubidium vapor cell is used to generate the bright twin beams of light. We observe more than 25% of temporal quantum noise reduction with respect to the shot-noise limit in images captured by the EMCCD camera. Compared with bucket detectors, EMCCD makes it possible to take advantage of the spatial and temporal quantum properties of light simultaneously, which would greatly benefit many applications using quantum protocols.
P. Jackson - One of the best experts on this subject based on the ideXlab platform.
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a unique Charge Coupled Device xenon arc lamp based imaging system for the accurate detection and quantitation of multicolour fluorescence
Electrophoresis, 2001Co-Authors: Carole Spibey, P. Jackson, Klaus HerickAbstract:In recent years the use of fluorescent dyes in biological applications has dramatically increased. The continual improvement in the capabilities of these fluorescent dyes demands increasingly sensitive detection systems that provide accurate quantitation over a wide linear dynamic range. In the field of proteomics, the detection, quantitation and identification of very low abundance proteins are of extreme importance in understanding cellular processes. Therefore, the instrumentation used to acquire an image of such samples, for spot picking and identification by mass spectrometry, must be sensitive enough to be able, not only, to maximise the sensitivity and dynamic range of the staining dyes but, as importantly, adapt to the ever changing portfolio of fluorescent dyes as they become available. Just as the available fluorescent probes are improving and evolving so are the users application requirements. Therefore, the instrumentation chosen must be flexible to address and adapt to those changing needs. As a result, a highly competitive market for the supply and production of such dyes and the instrumentation for their detection and quantitation have emerged. The instrumentation currently available is based on either laser/photomultiplier tube (PMT) scanning or lamp/Charge-Coupled Device (CCD) based mechanisms. This review briefly discusses the advantages and disadvantages of both System types for fluorescence imaging, gives a technical overview of CCD technology and describes in detail a unique xenon/are lamp CCD based instrument, from PerkinElmer Life Sciences. The Wallac-1442 ARTHUR is unique in its ability to scan both large areas at high resolution and give accurate selectable excitation over the whole of the UV/visible range. It operates by filtering both the excitation and emission wavelengths, providing optimal and accurate measurement and quantitation of virtually any available dye and allows excellent spectral resolution between different fluorophores. This flexibility and excitation accuracy is key to multicolour applications and future adaptation of the instrument to address the application requirements and newly emerging dyes.
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Two-dimensional polyacrylamide gel electrophoresis of proteins labeled with the fluorophore monobromobimane prior to first-dimensional isoelectric focusing : imaging of the fluorescent protein spot patterns using a cooled Charge-Coupled Device
Analytical Biochemistry, 1993Co-Authors: V.e. Urwin, P. JacksonAbstract:Abstract A new method for visualizing 2D protein spot patterns is described whereby proteins containing sulfydryl groups are labeled with the fluorophore monobromobimane prior to the isoelectric focusing step of 2D polyacrylamide gel electrophoresis. The method requires the addition of a single reagent and a delay of only 15 min during sample preparation. High resolution spot patterns were obtained without the need for any postelectrophoretic gel handling. The gel patterns were imaged digitally immediately postelectrophoresis while the gels were still within their glass electrophoresis cassettes. The imaging system was based on a cooled Charge-Coupled Device. The fluorescent spot patterns of proteins from the lymphoid cell-line IM9 were similar but not identical to silver-stained gel spot patterns of the same but underivatized sample. There was an overall increase (approx. 10%) in the number of spots visible on the fluorescent gels compared to those visible on the silver-stained gels.
C P Hauri - One of the best experts on this subject based on the ideXlab platform.
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high performing nonlinear visualization of terahertz radiation on a silicon Charge Coupled Device
Nature Communications, 2015Co-Authors: Mostafa Shalaby, C Vicario, C P HauriAbstract:Photoinduced electron transitions can lead to significant changes of the macroscopic electronic properties in semiconductors. This principle is responsible for the detection of light with Charge-Coupled Devices. Their spectral sensitivity is limited by the semiconductor bandgap which has restricted their visualization capabilities to the optical, ultraviolet, and X-ray regimes. The absence of an imaging Device in the low frequency terahertz range has severely hampered the advance of terahertz imaging applications in the past. Here we introduce a high-performing imaging concept to the terahertz range. On the basis of a silicon Charge-Coupled Device we visualize 5-13 THz radiation with photon energy under 2% of the sensor's band-gap energy. The unprecedented small pitch and large number of pixels allow the visualization of complex terahertz radiation patterns in real time and with high spatial detail. This advance will have a great impact on a wide range of terahertz imaging disciplines.
Shunichi Sato - One of the best experts on this subject based on the ideXlab platform.
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diffuse light reflectance signals as potential indicators of loss of viability in brain tissue due to hypoxia Charge Coupled Device based imaging and fiber based measurement
Journal of Biomedical Optics, 2013Co-Authors: Satoko Kawauchi, Izumi Nishidate, Yoichi Uozumi, Hiroshi Nawashiro, Hiroshi Ashida, Shunichi SatoAbstract:Brain tissue is highly vulnerable to ischemia/hypoxia, and real-time monitoring of its viability is important. By fiber-based measurements for rat brain, we previously observed a unique triphasic reflectance change (TRC) after a certain period of time after hypoxia. After TRC, rats could not be rescued, suggesting that TRC can be used as an indicator of loss of brain tissue viability. In this study, we investigated this diffuse-reflectance change due to hypoxia in three parts. First, we developed and validated a theoretical method to quantify changes in the absorption and reduced scattering coefficients involved in TRC. Second, we performed Charge-Coupled-Device-based reflectance imaging of the rat brain during hypoxia followed by reoxygenation to examine spatiotemporal characteristics of the reflectance and its correlation with reversibility of brain tissue damage. Third, we made simultaneous imaging and fiber-based measurement of the reflectance for the rat to compare signals obtained by these two modalities. We observed a nontriphasic reflectance change by the imaging, and it was associated with brain tissue viability. We found that TRC measured by the fibers preceded the reflectance-signal change captured by the imaging. This time difference is attributable to the different observation depths in the brain with these two methods.
Janusz Pawliszyn - One of the best experts on this subject based on the ideXlab platform.
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absorption spectra and multicapillary imaging detection for capillary isoelectric focusing using a Charge Coupled Device camera
Analyst, 1995Co-Authors: Janusz PawliszynAbstract:Two absorption imaging detectors using Charge Coupled Device (CCD) cameras are designed for capillary isoelectric focusing (CIEF). In the first detector, a light beam passes through a 4 cm capillary and is dispersed by a grating onto a CCD camera. The two-dimensional CCD in the camera records the light absorption at different positions along the capillary in one dimension, and at different wavelengths in the second dimension, simultaneously. The resolution in wavelength is about 1 nm. Since the separation time in the 4 cm long capillary column is only 4 min, the complete analysis takes 4 min, which is much faster than conventional CIEF methods. In the second detector, a light beam passes through a capillary array and then onto a CCD camera. Isoelectric focusing separation and detection of several samples can be completed in about 4 min, and the focusing processes in all capillaries can be observed simultaneously by the real-time, on-line imaging detector. In both detectors, images are normalized by light intensity, recorded simultaneously with the images, to compensate for intensity fluctuation of the light source. The detection limit of the detector is 1.5 × 10–3 absorbance units. The pH resolution of the instrument with the 4 cm long capillaries is 0.01 which is the same or better than that of conventional CIEF instruments with much longer capillaries. The deviation in pH of replicate zone positions in different capillaries of the capillary array is less than 0.01 which is much better than capillary array IEF methods using the mobilization process.