Coherent anti-Stokes Raman scattering microscopy with spectrally tailored ultrafast pulses

We report a coherenti-Stokes Raman scattering (CARS) microscopy method using tailored ultrafast pulses from a broadband chirped-pulse-amplification Ti: Sapphire laser. Three input waves were obtained at the pulse compressing stage. An air-spaced etalon was used to generate the narrow band waves (2ω1), and a hard aperture mask was used to produce the broadband wave (ω2). Spectral resolution as high as 7cm−1 can be achieved with the etalon, and the temporal resolution was ∼1 picosecond. Two-dimensional (2D) time-resolved vibrational CARS spectrographs covering 820–1500cm−1 were obtained from opaque and transparent thin films.