Practical implementation of Raman spectroscopy

Although the relative low efficiency of Raman scattering may be seen as a distinct drawback for practical applications, it turns out that it still can be a very valuable alternative to other spectroscopic techniques. In particular, Raman spectroscopy can become extremely attractive if rapid multispecies analysis is an issue. In multispecies LIF a tuneable laser system is required, which in most cases will have to be tuned over a wide spectral range to probe all desired species sequentially. In contrast, by virtue of its non-resonant nature, only a single fixed-frequency laser is required in Raman spectroscopy. On the detection side, all the traditional means of spectral dispersion and photodetection can be applied, as was outlined in Chapter 7 for LIF. The only care to be taken is to provide a means for 

The most common implementation of Raman spectroscopy is the combination of a standard spectrograph coupled to a CCD array detector. The suppression of any of the popular excitation wavelengths (see Table 8.2) is achieved by using either so-called notch or razor-edge filters. 

CHS LIGHT SCAHERING METHODS RAMAN SPECTROSCOPY AND OTHER PROCESSES 

The recorded spectrum for air clearly reveals the intensity ratio expected from the main constiments of air, i.e. N2 (78.1 per cent) and O2 (20.9 per cent), based on the relative intensity parameters listed in Table 8.1. Also, the break-off of the pure rotational 5oo(S)-branch is clearly evident. 

The spectra for the H2 D2 mixture exhibit both pure rotational and ro-vibrational Raman features, i.e. Soo(5)- and Soi(G)-branches (the Soi( 9)- and Soi(5)-branches are too weak to be seen above the detector noise. Because of the huge isotope effect the pure rotational Raman lines are well resolved, even at 

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