What Is EMCCD Technology
Definition of EMCCD Technology
EMCCD technology is a digital scientific detector innovation first introduced to
the imaging community by
Andor Technology Plc. in early 2000, followed by a spectroscopy version
in early 2005. At the time, Andor coined the term ‘Electron Multiplying Charge Coupled
Device (EMCCD)’ to amply describe the underlying process that defines this novel
new technology platform.*
EMCCD is a quantitative digital camera technology that is capable of detecting single
photon events whilst maintaining high Quantum Efficiency, achievable by way of a
unique electron multiplying structure built into the sensor.
Unlike a conventional CCD, an EMCCD is not limited by the readout noise of the output
amplifier, even when operated at high readout speeds. This is achieved by adding
a solid state Electron Multiplying (EM) register to the end of the normal serial
register; this register allows weak signals to be multiplied before any readout
noise is added by the output amplifier, hence rendering the read noise negligible.
The EM register has several hundred stages that use higher than normal clock voltages.
As charge is transferred through each stage the phenomenon of Impact Ionization
is utilized to produce secondary electrons, and hence EM gain. When this is done
over several hundred stages, the resultant gain can be (software) controlled from
unity to hundreds or even thousands of times.
* The term has since become the industry standard, used by almost every manufacture
and user of this technology.