MCP image intensifier with improved DQE

Airey, R.; Norton, Timothy; Morgan, B. L.; Fordham, J. L. A.; Bone, D. A.; Powell, J. R.

doi:10.1117/12.19474

Cited by 4 publications

(6 citation statements)

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“…The peak detective quantum efficiency is about 20% at 350 nm, and falls to about 10% at 500 nm. At 600 nm and 700 nm it is around 5% and 2%, respectively [28,29]. The background noise is less than 5 counts cm −2 s −1 and is mainly due to thermal emission from the photocathode.…”

Section: Description Of the Instrumentmentioning

confidence: 96%

“…Although originally developed for use in astronomy [28,29], large area photon counting detectors are ideally suited for a range of other uses including fluorescence imaging and fluorescence microscopy. Applications to fields such as autoradiography and bioluminescence have recently been reported [30][31][32][33].…”

Section: Photon Event Counting Imaging With Position-sensitive Detectorsmentioning

confidence: 99%

“…The detected photon events are read out with a CCD camera, and the event processing is performed in a PC using software designed for this purpose. The image intensifier and the CCD camera are mounted on the camera port of a fluorescence microscope (Zeiss) with a high pressure mercury lamp as The image intensifier (see figure 2), which was manufactured by Photek Ltd 1 , is a dual proximity-focused, 40 mm diameter, three-MCP Z-stack device with a bialkali photocathode, a P20 (ZnSCd(Ag)) phosphor and a photon gain of 10 7 [28,29]. The photocathode is operated at ground potential, and the operating voltages of the intensifier are 150 V between the photocathode and the first MCP, 800 V between the first and second MCP, 2350 V between the second and third MCP and 4500 V between the third MCP and the phosphor [36].…”

Section: Description Of the Instrumentmentioning

confidence: 99%

“…The photocathode is operated at ground potential, and the operating voltages of the intensifier are 150 V between the photocathode and the first MCP, 800 V between the first and second MCP, 2350 V between the second and third MCP and 4500 V between the third MCP and the phosphor [36]. The MCPs have 12 µm pores on 15 µm centres, with a length-to-diameter ratio of 40:1 for the first MCP and 80:1 for the two rear MCPs [28,29,36]. The peak detective quantum efficiency is about 20% at 350 nm, and falls to about 10% at 500 nm.…”

Section: Description Of the Instrumentmentioning

confidence: 99%

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A position-sensitive photon event counting detector applied to fluorescence imaging of dyes in sol-gel matrices

Suhling

Hungerford

Airey

et al. 2001

Meas. Sci. Technol.

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A photon event counting imaging detector, originally developed for astronomical applications, has been adapted for use on a low light level fluorescence microscope. It is based on a 40 mm diameter, three-microchannel plate image intensifier with a photon gain of 107 when operating in the photon event counting mode. The intensifier's output screen is lens coupled to a full frame progressive scan CCD camera which transfers the photon event data into a PC via a framegrabber. The image is built up from the photon events in the frames using software-based event processing. The high sensitivity of the photon counting approach means that low excitation light levels and/or a low probe concentration can be used. Moreover, the inherent linearity between incident intensity and the number of detected events provides intrinsic photometric accuracy independent of camera gain and offset. To demonstrate the viability of photon event counting imaging applied to fluorescence studies, we have imaged 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran- (DCM-) and rhodamine 6G-doped thin films produced by the sol-gel technique using tetraethylorthosilicate (TEOS) as a precursor. We show that fluorescence imaging is a feasible tool for finding cracks, streaks or other defects and for assessing the uniform thickness of the finished films. In addition, we image the fluorescence in response to an excitation beam illuminating rhodamine 6G-doped bulk monolith sol-gel samples. The results are analysed using the Lambert-Beer law.

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Section: Description Of the Instrumentmentioning

confidence: 96%

Section: Photon Event Counting Imaging With Position-sensitive Detectorsmentioning

confidence: 99%

Section: Description Of the Instrumentmentioning

confidence: 99%

Section: Description Of the Instrumentmentioning

confidence: 99%

See 2 more Smart Citations

A position-sensitive photon event counting detector applied to fluorescence imaging of dyes in sol-gel matrices

Suhling

Hungerford

Airey

et al. 2001

Meas. Sci. Technol.

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“…Moreover, MCPs are frequently coated with a protective film to prevent damage to the cathode caused by ion feedback, and this further reduces the sensitivity. Attempts to improve the DQE of these devices have included flaring the inputs of the microchannels to increase their open area ratio, applying a bias voltage to draw electrons into the channels (Lampton, 1981), and removing the thin film on the input of the MCP (Airy et al, 1990). Although unfilmed MCPs have better sensitivity, they have a reduced life expectancy.…”

Section: Detective Quantum Efficiencymentioning

confidence: 99%

Group Delay Tracking with the Sydney University Stellar Interferometer

Lawson¹

1994

PASP

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In the Sydney University Stellar Interferometer (SUSI), fringes are detected when the optical path-difference between the arriving wavefronts is less than the coherence length for the observation. While observing a star, it is necessary to compensate not only for the changes in pathlength due to the earth's rotation, but also for those due to the effects of atmospheric turbulence. Apertures smaller than r 0 are used and active tilt-compensation is employed so that the wavefronts in the combined beams are made parallel. The remaining path-difference between the wavefronts must then be tracked for an accurate calibration of the fringe visibility. Improved tracking allows larger bandwidths to be used and therefore improves the sensitivity of the instrument. In this thesis a fringe tracking system is developed for SUSI based on group delay tracking with a PAPA detector. The method uses short exposure images of fringes detected in the dispersed spectra of the combined starlight. The number of fringes across a fixed bandwidth is directly proportional to the path-difference between the arriving wavefronts, and a Fast Fourier Transform is used to calculate the spatial power spectrum of the fringes, thereby locating the delay. Several topics are developed in the thesis. The visibility loss due to a non-constant fringe spacing on the detector is investigated, and the improvements obtained from rebinning the photon data are shown. The low light level limitations of group delay tracking are determined, with emphasis on the probability of tracking error, rather than on signalto-noise performance. Experimental results from both laboratory studies and stellar observations are presented. These show the first closed-loop operation of a fringe tracking system based on observations of group delay with a stellar interferometer. A new photon counting PAPA detector is also described, which was developed for use in this work. The design principles of the PAPA camera are outlined, and the potential sources of image artifacts are identified. These artifacts arise from the use of optical encoding with Gray coded masks. The new camera is distinguished by its mask-plate, which was designed to overcome artifacts due to vignetting. New lens mounts are also presented which permit a simplified optical alignment without the need for tilt-plates. The performance of the camera is described and its images are shown to be free of the effects of vignetting. i Declaration of Originality To the best of my knowledge, this thesis contains no copy or paraphrase of work due to any other person, except where duly acknowledged. None of the remaining work has been presented for any degree at the University of Sydney or elsewhere.

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