Electron Multiplication CCDs Offer a Flexible Solution

A recent advance in CCD technology is the introduction of electron multiplication or charge carrier multiplication CCDs. This technology is effective in applications requiring high light sensitivity, high spatial resolution and reasonably high frame rates at either short or long exposure times. However, the devices may not prove superior to intensified CCDs when it comes to applications that need extremely short exposure times.

Electron multiplication CCDs use a conventional readout-node amplifier design but apply gain to the signal prior to readout. The benefit is an increase in the magnitude of signal charge being digitized at the same readout noise (Figure 1). For applications that are time-sensitive or that suffer from phototoxicity, such as live-cell or ion imaging, the ability to amplify the signal by maintaining a low exposure time is beneficial. Traditionally, this has been accomplished by using intensified CCD cameras, which also amplify signal but at the cost of image degradation and reduced dynamic range caused by various noise sources.