PerkinElmer RamanFlex 400, Getting Started Manual

Page: 33 / 94

Raman History, Theory and Instrumentation . 33
Range 1 + Range 2 + Range 3 + Range 4 = Complete Spectrum (all ranges acquired
simultaneously).
Figure 11 shows a schematic diagram of light falling on the CCD detector. Here 4 strips of
light are shown for clarity, but in practice up to 12 strips are acquired and resolution of up to
2 cm
−1
(peak FWHM) can be achieved.
The advantages of PerkinElmer’s Echelle spectrograph are:
• Full spectral range at high resolution in a single acquisition.
•
It takes less than a second to acquire a high resolution spectrum with a full spectral
range.
•
There are no moving parts in the spectrograph, which improves instrument reliability,
ruggedness and the quality of calibration.
• The absence of moving parts also means that as you acquire the spectrum, there is no
change in the spectrograph’s stray light performance, meaning that there are no stitch
marks in the final spectrum.
No light is lost, all the light goes onto the detector, and all the strips are readout
simultaneously. The concept of an Echelle detector is not unique to PerkinElmer. Echelle
detectors are commonly used in applications where high resolution
and wide spectral range are
required.
Examples include plasma spectroscopy (ICP and LIBS) and Echelle detectors find
very widespread use in astronomy.