CARS (Coherent Antistokes Raman Scattering) has been known for more than thirty years and is characterized by certain advantages and disadvantages compared to Raman spektroscopy. One drawback is the requirement of a relatively complex laser arrangement. With the availability of new compact short-pulse lasers and white light generation with photonic fibers broadband CARS arrangements are now easier to adjust and allow a short measurement time.
Important advantages of CARS are: fluorescence and luminescence suppression and a significantly stronger Raman signal.
Soliton offers a CARS option to a Raman microscope consisting of a sub-ns microchip laser for white light generation. The two laser beams are coupled onto the sample under a microscope and the CARS signal can be observed with the Raman microscope.
To record the CARS spectra, the software of the Raman microscope is used. In this way the same sample under the microscope can be studied both in the Raman Effect and with the CARS effect with subsequent comparison of the two spectra. Especially for highly fluorescent samples, as are often the case in biological tissues, the CARS option proves to be very useful.
An important field of application is medical technology, where rapid mapping of tumor tissue is a decisive advantage. Also food and environmental analysts are increasingly becoming interested in CARS since now Raman measurements are possible which have so far failed due to fluorescence.
For more information and sample spectra follow the link to applications (German version).