Single-pulse coherent anti-Stokes Raman scattering microscopy employing an octave spanning pulse

We demonstrate two complementary types of microscopy using an identical setup for single-pulse coherent anti-Stokes Raman scattering (CARS) imaging, which employs an ultrabroadband laser pulse with a spectral bandwidth of 4800 cm^-1 and enables the suppression of nonresonant CARS signals. One is a novel type of microscopy that uses spectral phase modulation for the selective excitation of a single Raman mode. The selective excitation is achieved by the modulated pulse focusing its difference-frequency spectrum into a narrow spectral region. Another type is Fourier-transform CARS (FT-CARS) microspectroscopy based on the measurement of the CARS spectrum obtained from the Fouriertransform of the interferometric autocorrelation (IAC) signal. Vibrational spectral imaging of chemical and biological samples is demonstrated using the two types of microscopy.