Specifications

Table Of Contents
Version 1.1 rev Jan 2013
Page 41
iXon Ultra
, Features and Functionality
S/N plots derived from the specications of the back-illuminated iXon Ultra EMCCDs at 1MHz (slower frame rate
operation) read out either with EM Gain ON or, alternatively, through the conventional amplier (i.e. standard CCD
operation) are shown in Figure 10. Again, this plot assumes a photon wavelength at which the QE of the sensor is 90%.
This gure applies specically to models where the user has the choice of either EMCCD or conventional ampliers.
At these slower speed operations, when one has the choice to read out as a “conventional” CCD, it can often be
advantageous to do so in order to achieve improved signal to noise. The plots below show that the cross-over point is at
~42 photons/pixel, at which it is still advisable to read out through the EM amplier with Gain applied.
Figure 10: EM Gain ON vs. Conventional Amplier signal to noise plots for back-illuminated iXon Ultra EMCCDs at 1MHz readout speed