Glossary of Terms
98
Here, the total system noise takes into account the CCD array’s read noise, as well as,
the noise contribution from the detector system’s electronics as follows:
Noise
s
Electronic
Noise
Read
CCD
Noise
System
Total
2
2
e
e
e
+
=
It is important to note that the above calculation for total system noise assumes a 1 ms
integration time and ignores the noise contributions from the array’s dark current shot
noise and the signal itself (i.e. shot noise).
Electrons/Count
Electrons per count is a system level “transfer function” parameter or gain related
value that equates the number of electrons required to generate a single ADC count.
Etaloning
When a very thin piece material is used as an optical component, multiple
interference patterns may be observed. This effect is called
Etaloning
. When the
thickness of the material is on the order of the wavelength of light passed through,
etaloning may prevent the detector from distinguishing an actual signal from the
interference pattern. Etaloning is problematic with backthinned CCD chips in the
wavelength range 700 nm to 1100 nm.
Felgett's Advantage
Multi-channel detection provides an improvement in signal to noise ratio, as
compared to single channel (scanned) spectral detection. Because the multi-channel
detection acquires a number of spectral elements simultaneously, the S/N is improved
by a factor proportional to the square root of the number of channels acquired given
the experiment times are equal.
Flush
To reduce noise and maximize dynamic range at the CCD, the dark charge that has
accumulated on the chip can be rapidly removed by flushing. The effect of flushing
the array is similar to a readout cycle in that the charges are cleared from the pixels. A
flush is much faster than a frame readout since it dumps the charges without
conversion. Flushing is only necessary when there is an appreciable time between
readouts.
Full Well Capacity
Full well capacity
is the measure of how much charge can be stored in an individual
pixel. This specification varies for each chip type. It depends on the doping of the
silicon, architecture and pixel size. The quantum well capacity is usually around
300,000 electrons. The greater the well, the greater the
Dynamic Range
. A chip with
a larger full well capacity can record a higher signal level before saturating. See also
Variable Gain
.
Summary of Contents for JOBIN YVON SYNAPSE
Page 1: ...SYNAPSE CCD Detection System User Manual Part Number 81100 Revision 2...
Page 10: ...Preface x...
Page 14: ...System Description and Specifications 4...
Page 28: ...Detector System Installation 18...
Page 38: ...Initial Power up and Operation 28...
Page 48: ...Temperature Control 38...
Page 72: ...Appendix A Dimensional Drawings 62 Figure 17 Distance from Focal Plane to CCD Chip...
Page 73: ...Appendix A Dimensional Drawings 63 Figure 18 Synapse Power Supply Unit...
Page 74: ...Appendix A Dimensional Drawings 64...
Page 86: ...Appendix C Performing Routine Procedures with SynerJY 76...
Page 100: ...Appendix E Accessories 90...
Page 104: ...Warranty 94...
Page 113: ...103 Notes...
Page 114: ...104 Notes...