&lt;title&gt;Electron multiplying CCDs&lt;/title&gt;

Denvir, Donal J.; Conroy, Emer

doi:10.1117/12.463677

Cited by 24 publications

(9 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, in early 2000, Electron Multiplying Charge Coupled Devices (EMCCDs) were developed as image sensors capable of detecting single photon events without an image intensifier. This was achieved by way of a unique electron multiplying structure built directly into the chip and enables solar observers to attain high-contrast images without the drawbacks associated with long exposure times (Denvir and Conroy, 2003).…”

Section: Electron Multiplying Ccdsmentioning

confidence: 99%

ROSA: A High-cadence, Synchronized Multi-camera Solar Imaging System

et al. 2010

View full text Add to dashboard Cite

Rapid Oscillations in the Solar Atmosphere (ROSA) is a synchronized, six camera high cadence solar imaging instrument developed by Queen's University Belfast. The system is available on the Dunn Solar Telescope at the National Solar Observatory in Sunspot, New Mexico, USA as a commonuser instrument. Consisting of six 1k × 1k Peltier-cooled frame-transfer CCD cameras with very low noise (0.02 -15 e s −1 pixel −1 ), each ROSA camera is capable of full-chip readout speeds in excess of 30 Hz, or 200 Hz when the CCD is windowed. Combining multiple cameras and fast readout rates, ROSA will accumulate approximately 12 TB of data per 8 hours observing. Following successful commissioning during August 2008, ROSA will allow multi-wavelength studies of the solar atmosphere at high temporal resolution.

show abstract

Section: Electron Multiplying Ccdsmentioning

confidence: 99%

ROSA: A High-cadence, Synchronized Multi-camera Solar Imaging System

et al. 2010

View full text Add to dashboard Cite

show abstract

“…The characteristic SNR of the camera was approximately SNR = 50 for the EMG settings shown in the images. Due to the EMCCD characteristics, the dynamic range of the camera is reduced as the EMG is increased further [8]. However, plots in Figure 3 show that the effective dynamic range in our camera is large enough to image the fluorescence spectra from the samples and keeping a relatively high SNR.…”

Section: Resultsmentioning

confidence: 88%

Hyperspectral low-light camera for imaging of biological samples

Hernandez-Palacios

Randeberg

Baarstad

et al. 2010

2010 2nd Workshop on Hyperspectral Image and Signal Processing: Evolution in Remote Sensing

View full text Add to dashboard Cite

The capability of acquiring hyperspectral information in low light conditions is potentially important for a variety of applications, ranging from remote sensing to biomedical fluorescence imaging. Particularly interesting is its use in optical analysis of biological samples in which the light level should be kept low to prevent tissue damage. For this purpose a low-light hyperspectral camera has been developed for the 0.4 to 0.9 µm spectral range. The camera is based on an electron-multiplying CCD (EMCCD) detector which effectively suppresses readout noise, and approaches the fundamental photon noise limit. It has been designed with close-up optics to image an area on the order of centimeters. Fluorescence images of skin samples illustrate the camera performance. Results show that low-light hyperspectral imaging has a potential for biomedical applications.Index Terms-biomedical imaging, fluorescence imaging, hyperspectral imaging, low-light imaging. I TRODUCTIOHyperspectral imaging, also referred to as imaging spectroscopy, collects spatially resolved spectral information from the imaged scene. It has traditionally been applied to remote sensing and military surveillance. However, many new applications have emerged in areas like medicine, chemistry, geology, food science and industrial processes [1][2][3]. In order to acquire useful data, the noise floor of the device must be lower than the signal level generated by the photon flux. This requirement can be met with relative ease in daytime remote sensing, and also in laboratory or industrial applications where bright artificial illumination sources can be used to get an adequate signal-to-noise ratio (SNR).However, there are other potential applications with inherently low light environments, such as dusk-to-dawn remote sensing or laboratory imaging of light-degradable samples. Hyperspectral fluorescence imaging of living tissue or other biological samples is an example of the latter. Typically, fluorescent signals are several orders of magnitude weaker than the excitation sources used, and the excitation is limited by the sample damage threshold. It has been demonstrated that with a sensitive camera, it is possible to obtain spectral information from poorly illuminated scenes with photon noise limited SNR [4]. Such low-light performance can be achieved using an electron-multiplying CCD array (EMCCD), where the internal gain can be used to lift weak signals above the readout noise.Here we report on a new EMCCD-based hyperspectral camera design for low-light imaging. The camera has been tailored for a range of biomedical applications with varying light levels and object distances. With a scene pixel size of 25 µm, the resolution is lower than in microscopy, but the setup is capable of imaging objects several centimeters in size.In biomedical applications, this permits imaging of relatively large tissue samples, thus providing useful information complementary to that obtained from microscopy-based methods [5]. The overall performance of the camera was tested by fl...

show abstract

“…[7]. On-chip electron multiplying (EM) gain -produced by impact ionization in a dedicated EM readout register -increases the average signal above the noise floor of the amplifier.…”

Section: Low Light Level (L3)-ccd Technologymentioning

confidence: 99%

The superiority of L3-CCDs in the high-flux and wide dynamic range regimes

Butler¹,

Sheehan²

2008

AIP Conference Proceedings

View full text Add to dashboard Cite

Low Light Level CCD (L3-CCD) cameras have received much attention for high cadence astronomical imaging applications. Efforts to date have concentrated on exploiting them for two scenarios: post-exposure image sharpening and "lucky imaging", and rapid variability in astrophysically interesting sources. We demonstrate their marked superiority in a third distinct scenario: observing in the high-flux and wide dynamic range regimes. We realized that the unique features of L3-CCDs would make them ideal for maximizing signal-to-noise in observations of bright objects (whether variable or not), and for high dynamic range scenarios such as faint targets embedded in a crowded field of bright objects. Conventional CCDs have drawbacks in such regimes, due to a poor duty cycle -the combination of short exposure times (for time-series sampling or to avoid saturation) and extended readout times (for minimizing readout noise). For different telescope sizes, we use detailed models to show that a range of conventional imaging systems are photometrically out-performed across a wide range of object brightness, once the operational parameters of the L3-CCD are carefully set. The cross-over fluxes, above which the L3-CCD is operationally superior, are surprisingly faint -even for modest telescope apertures. We also show that the use of L3-CCDs is the optimum strategy for minimizing atmospheric scintillation noise in photometric observations employing a given telescope aperture. This is particularly significant, since scintillation can be the largest source of error in timeseries photometry. These results should prompt a new direction in developing imaging instrumentation solutions for observatories.Keywords: EM-CCD/L3-CCD Detectors -observational dynamic range -exposure time calculation -observing duty cycle -scintillation -photometric variability PACS: 95.75.Wx, 95.55.Aq, 95.75.Tv, 95.55.n, 87.57.Ce

show abstract

<title>Electron multiplying CCDs</title>

Cited by 24 publications

References 7 publications

ROSA: A High-cadence, Synchronized Multi-camera Solar Imaging System

ROSA: A High-cadence, Synchronized Multi-camera Solar Imaging System

Hyperspectral low-light camera for imaging of biological samples

The superiority of L3-CCDs in the high-flux and wide dynamic range regimes

Contact Info

Product

Resources

About