The Echelle Spectrograph - PerkinElmer RamanMicro 300 Series Getting Started Manual

Raman History, Theory and Instrumentation . 27

The Echelle Spectrograph

Figure 8 Schematic of the Echelle Spectrograph
The RamanMicro 300 is connected to the Echelle spectrometer in the RamanStation 400F or
RamanFlex 400 Series. The spectrometer contains two components; the Echelle spectrograph
and a two ̵ dimensional CCD detector. The spectrograph works by dispersing the light in two
dimensions by using two gratings (Figure 8). The first grating disperses the light horizontally
onto the second grating, where the light is further dispersed vertically onto the CCD detector.
The light is spread over a number of strips on the CCD that are read simultaneously,
therefore a full spectral range (at high resolution) can be achieved with one acquisition.
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Figure 9 Strips of light on the CCD detector using the Echelle spectrograph
Range 1 + Range 2 + Range 3 + Range 4 = Complete Spectrum (all ranges acquired
simultaneously).
Figure 9 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
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2 cm (peak FWHM) can be achieved.