horiba JOBIN YVON SYNAPSE, Руководство пользователя

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Detector System Component Description
47
System Noise
From a system perspective, total system noise is typically specified in electrons RMS at a
minimum integration time (i.e. Tint = 0 sec). This CCD detection system parameter is
comprised from three major sources:
● CCD Read noise
● Electronics noise
● CCD Dark Current Shot noise
Calculation of the detection system’s total baseline noise is arrived at using the following
equation:
Total System Noise =
For the purposes of this manual, system noise contributions from the CCD’s dark current
shot noise or noise contributions from the signal itself (i.e. shot noise) are ignored. In
general, thermoelectrically cooled CCD detection systems, as exemplified by the Synapse
CCD Detection System, typically have negligible dark current especially when
considering minimum integration times, and as such, contribute fractions of an electron
to this figure of merit system parameter. Thus, total system noise is primarily influenced
by the associated read noise of the selected CCD’s output amplifier structure, as well as,
the detection system’s electronics.
For the Synapse CCD Detection System, typical system noise figures range between 3 to
5 electron RMS (i.e. 1 sigma), and are largely dependent on the specific sensor used as
compared to the system’s electronics. It should be noted that the Synapse CCD Detection
System incorporates the lowest noise front-end analog architecture in an effort not to
compromise the system’s baseline noise or effective dynamic range. To illustrate the
dependency and impact the CCD’s read noise has on the overall noise floor within the
Synapse architecture, system noise is calculated below for an E2V CCD30 device
operating at a 20 kHz pixel processing rate:
E2V CCD30 Read Noise = 3.28 e-
Synapse Electronics Noise = 1.20 e-
Dark Shot Noise = 0 (ignored)
Total System Noise
= = 3.5 e- RMS
As illustrated by the above example, the Synapse CCD Detection System’s total noise is
limited by the sensor’s read noise with minimal contribution and/or impact from the
electronics suite.
It should be noted that from a user’s visual prospective, this 3 to 5 electron RMS value
only signifies a statistical measurement where any individual “dark” scan can encompass
pixel readouts with peak-peak electron variation of approximately 5.5 times the stated
2 2 2
[0] e-] [1.2 e-] [3.28
+ +
2 2 2
Noise] Shot [Dark Noise] cs [Electroni Noise] Read [CCD
+ +