Single-beam CARS applications

Equation (7.5) is very important for single-beam CARS applications, because it quantifies the range of vibrational modes that can be accessed with a given laser pulse. Clearly, pulses with a broader spectrum and thus higher optical bandwidth allow covering a wider range of vibrational energies, as has also been pointed out in Table 7.1. It is, however, absolutely necessary that the pulses are perfectly compressed in the sample, so that all colors arrive at the same time. 

The added benefit of intrinsic interferometric detection is only a further example of the great flexibility of using the pulse shaper in single-beam nonlinear microspectroscopy. The setup used here for CARS in its variants is, of course, also capable of immediately performing all the other nonlinear microspectroscopies simply by changing the shape of the excitation pulses with computer control. This is shown in the next section, where we discuss a broadband TPF application. 

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