Fourier Transform Coherent Anti-Stokes Raman Scattering Spectroscopy: A Comprehensive Review.

Fourier transform coherent anti-Stokes Raman scattering (FT-CARS) spectroscopy is a powerful spectroscopic method that combines the principles of Fourier transform spectroscopy with coherent anti-Stokes Raman scattering (CARS). This method stands out in spectroscopy for its ability to rapidly acquire coherent Raman spectra, achieving an impressive rate of over 10 000 spectra per second. The method involves scanning the optical delay between two femtosecond pulses; the initial pulse induces a vibrational coherence in the sample, while the subsequent pulse probes this coherence over increasing delays. The anti-Stokes scattering intensity generated is modulated by the vibrational dynamics of the sample, enabling the retrieval of Raman spectra through Fourier transformation. Over the past two decades, FT-CARS spectroscopy has undergone substantial evolution, paving the way for its application in a wide array of fields, including material analysis and flow cytometry. In this comprehensive Review, we explore the fundamental principles and diverse applications of FT-CARS spectroscopy and delve into the potential future advances and challenges associated with this emerging method.