A form of Raman spectroscopy (see Raman effect) enabling the intensity of Raman transitions to be increased. In this technique two laser beams with different frequencies pass through a sample producing electromagnetic radiation of several frequencies. It is possible to adjust the frequency of the lasers so that one of the frequencies corresponds to that of a Stokes line from the sample and the coherent emission has the frequency of the anti-Stokes line with a high intensity. CARS enables Raman spectra to be obtained even in the presence of other radiation. One application of CARS is to obtain Raman spectra from bodies in flames. Using this technique temperatures in different parts of the flame can be estimated from the intensity of the transitions.