Horiba Scientific FluoroMax-4 Operation Manual page 222

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FluoroMax -4 & FluoroMax -4P with USB rev. D (30 Jul 2012)
Internal conversion
Intersystem crossing
Intrinsic fluorescence
Jabłonski (energy) dia-
gram
Laser
Linearity
Low-pass filter
Luminescence
MCD shutter
Mercury lamp
Mirror-image rule
Molar extinction coeffi-
cient (ε)
Electronic transitions within an excited molecule that do not result in
emission. Also called a "non-radiative transition", this usually involves
changes in vibrational levels.
The electronic transition from the excited singlet state to the excited
triplet state before returning to the ground state. This transition in-
volves a change of spin that is quantum-mechanically forbidden, giving
a much longer timescale than fluorescence. This transition causes
phosphorescence on the timescale of microseconds to seconds.
The natural fluorescent properties of molecules.
A diagram that illustrates various energy levels and electronic transi-
tions available in a particular molecule. Possible paths for fluores-
cence, phosphorescence, and non-radiative transfers are shown on this
diagram, along with the various vibrational sub-levels available around
each energy level.
A monochromatic light source that provides high excitation intensity.
(1) Signal response; the desired response from a light detector is a line-
ar relationship. For example, when detector response is linear, if the
light intensity doubles, the detected signal also doubles. Most detectors
exhibit non-linear behavior near saturation. On the FluoroMax
emission photomultiplier tube is linear up to 2 million counts per se-
cond. Above this, pulse pileup occurs on the photon-counting module
(when multiple photons are counted as one). This results in a non-
linear response, and the detector efficiency drops. (2) Spectral position-
ing accuracy or tracking error of a spectrometer drive mechanism. See
Spectral Calibration.
Optical component that passes light of a lower wavelength.
The emission of light from matter excited from a variety of processes,
resulting in an electronic transition within the molecule to a lower en-
ergy state. See also: Bioluminescence, Chemiluminesence, Fluores-
cence.
Multi-channel device shutter. The Uniblitz
cycle time.
Light source that emits discrete, narrow lines as opposed to a continu-
um. A mercury lamp can be used to check the monochromator's cali-
bration.
When the emission profile appears to be the mirror image of the ab-
sorption spectrum.
The absorptivity of a particular substance, in M
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shutter is used for its rapid
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13-6
Glossary
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-4, the
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