The Megapixel EBCCD: A high-resolution imaging tube sensitive to single photons

Abstract

A h ybrid image-intensier tube, suitable for extremely low-light imaging, has been tested. This device is based on an Electron-Bombarded CCD chip (EBCCD) with 1024 1024 sensitive pixels. The tube, which has a photocathode diameter of 40 mm, is gateable and zoomable, with an image magnication varying from 0.62 to 1.3. The high gain (about 4000 collected electrons per photoelectron at the operational voltage of 15 kV) and the relatively low noise (180 electrons per pixel at 10 MHz pixelreadout frequency), allows single-photoelectron signals to be separated from noise with a signal-to-noise ratio greater than 10. By applying an appropriate threshold on the signal amplitude, the background can almost be eliminated, with a loss of few percent in single-photoelectron counting. High inner gain, low noise, single-photoelectron sensitivity, and high spatial resolution make the EBCCD imaging tube a unique device, attractive for many applications in high-energy physics, astrophysics, biomedical diagnostics.

Photon Counting Imaging with an Electron-Bombarded Pixel Image Sensor

“…The first commercially available EBCCD was made by Hamamatsu in 2000, and offered 1024 × 2014 pixels, operating voltage of 6–8 kV and a 3 Hz maximum frame rate [ 36 ]. Other EBCCD developments have reported frame rates up to 200 Hz [ 37 ], and maximum acceleration voltages of 14 kV and 15 kV [ 18 , 38 , 39 ]. Intensified EBCCDs, comprising a MCP between the photocathode and the CCD, have also been developed [ 40 ].…”

“…EB pixel image sensors were developed for high-resolution imaging with high signal-to-noise ratio at extremely low light level, and the low light level imaging capability has been utilised in night vision applications [ 27 , 41 , 42 ]. The single photon detection capabilities were first used in particle physics applications, for example, in observing neutrino interactions at CERN [ 39 ], and in astronomical applications [ 35 ]. Although recent developments in EMCCDs and sCMOS sensors have meant that the sensitivity advantage has disappeared [ 10 ], EB pixel image sensors continue to find applications in particle physics and in life science imaging.…”

Wide-field TCSPC-based fluorescence lifetime imaging (FLIM) microscopy

“…Single photon detection is also possible with electron-bombarded (EB) sensors, where the photoelectrons from the photocathode are accelerated directly into a CCD or CMOS sensor. [44][45][46][47] Unlike MCPs where the statistical electron multiplication process creates a broad pulse height distribution, in EB sensors the photon event brightness depends on the gain voltage. Thus, by sweeping the gain voltage during the exposure time, it could be possible to obtain photon arrival time information from the photon event brightness.…”

Wide-field time-correlated single photon counting-based fluorescence lifetime imaging microscopy

“…Single photon detection is also possible with electron-bombarded (EB) sensors, where the photoelectrons from the photocathode are accelerated directly into a CCD or CMOS sensor [62], [63], [64], [65], [66]. Unlike MCPs where the statistical electron multiplication process creates a broad pulse height distribution, in EB sensors the photon event brightness depends on the gain voltage.…”