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 Fourier-transform of the interferometric autocorrelation (IAC) signal. Vibrational spectral imaging of chemical and biological samples is demonstrated using the two types of microscopy.