Frequency-shifted megawatt soliton output of a hollow photonic-crystal fiber for time-resolved coherent anti-Stokes Raman scattering microspectroscopy

Abstract

Hollow-core photonic-crystal fibers (PCFs) provide soliton delivery and frequency shifting of 2.8 MW femtosecond pulses with an input central wavelength of 618 nm. The frequency-shifted megawatt soliton output of the hollow PCF is used as a high-peak-power Stokes field for coherent anti-Stokes Raman scattering (CARS) microspectroscopy, providing a dynamic range of nearly four decades for anti-Stokes signal detection, thus enabling time-resolved CARS studies of ultrafast relaxation processes on time scales from tens of femtoseconds up to tens of picoseconds.