Emccd Technology And On-Chip Multiplication Gain; Cooling; Figure 2-3: Emccd Array Structure Comparison: Frame Transfer, Kinetics - Teledyne ProEM Series System Manual

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2.2.1.1

EMCCD Technology and On-Chip Multiplication Gain

The principal difference between an electron-multiplying CCD (EMCCD) and a
traditional CCD is the presence of an extended serial register in the new device. See
Figure
Figure 2-3: EMCCD Array Structure Comparison: Frame Transfer, Kinetics, Full Frame
Multiplication Gain
For standard, high dynamic
Electrons are accelerated from pixel to pixel in the extended portion of the serial
register (also referred to as a multiplication register) by applying higher-than-typical
CCD clock voltages. This causes secondary electrons to be generated in the silicon by
impact ionization. The degree of multiplication gain is controlled by increasing or
decreasing the clock voltages for this register (gain is exponentially proportional to the
voltage). Although the probability of generating secondary electrons is fairly low
(typically 0.01 per stage), over the large number of stages of a typical multiplication
register, the total gain can be quite high.
This technology combines the ease of use and robustness of a traditional CCD with the
gain capabilities of an intensified CCD in a single device. The combination of this
technology with frame-transfer readout makes the ProEM cameras excellent choices
for experiments where fast framing and low light sensitivity are required.
2.2.2

Cooling

Dark current is reduced in ProEM camera systems through thermoelectric cooling of
the CCD arrays. Cooling by this method uses a Peltier cooler in combination with
air-circulation (i.e., fan,) and/or circulating coolant. To prevent condensation and
contamination from occurring, cameras cooled this way are evacuated. Due to CCD
size/packaging differences, the lowest achievable temperature can vary from one
ProEM model to the next. refer to the specific system's data sheet for cooling
performance.
ProEM System Manual
2-3.
Extended Multiplication Register
Output or Sensor Node
High Voltage Clock
Readout
Amplifier
For high speed, low
light level applications applications
Normal Voltage Clock
Standar d Serial Register
Low Noise
range applications
Readout
Amplifier
Output or Sensor Node
Frame-transfer Area
Sensor Area
ProEM:512B/1024B EMCCD
NOTE:
As the on-chip multiplication introduces additional noise, it
is recommended that the multiplication be used only as
required. For more information, refer to the On-Chip
Multiplication Gain technical note. This technical note can
be accessed by going to the Teledyne Princeton
Instruments web site: www.princetoninstruments.com.
Frame-transfer Area
Sensor Area
Masked Area
Sensor Area
ProEM:512BK EMCCD
Issue 3
Sensor Area
2 4
ProEM:1600 B/1600 B EMCCD