RESUMEN
A supercontinuum laser source was designed for multiplex-coherent anti-Stokes Raman scattering spectroscopy. This source was based on the use of a germanium-doped standard optical fiber with a zero dispersion wavelength at 1600 nm and pumped at 1064 nm. We analyzed the nonlinear spectro-temporal interrelations of a subnanosecond pulse propagating in a normal dispersion regime in the presence of a multiple Raman cascading process and strong conversion. The multiple Raman orders permitted the generation of a high-power flat spectrum with a specific nonlinear dynamics that can open the way to subnanosecond time-coded multiplex CARS systems.
RESUMEN
We generated a broad spectrum of light between 1064 and 1300 nm in the infrared by cascading stimulated Raman scattering in a potassium titanyl phosphate crystal while broadband conversion of the infrared Raman cascade was simultaneously achieved in the visible through second-harmonic generation (SHG) and sum-frequency mixing. We observed that odd- and even-order cascaded Stokes components were spatially addressed at different angles of propagation in the crystal. The efficiency of SHG and sum-frequency mixing is discussed as a function of the pump polarization. We also report on significant spatial distortions of the output Stokes beams.
