Generation of enhanced coherent anti-Stokes Raman spectroscopy signals in liquid-filled waveguides

Abstract

We have demonstrated enhancement of coherent anti-Stokes Raman spectroscopy signals in liquid benzene contained in dielectric waveguide capillaries with angular phase-matching conditions. Enhancement factors as high as 130 were observed relative to a single crossing. These were measured for capillaries of various cross sections as a function of length. The maximum enhancement we observed was in a 50-μm × 50-μm × 292-mm capillary with a sample volume of 0.75 μl. Signals increased steadily with capillary length and showed the same dependence on pump-beam crossing angle (phase-matching conditions) as in bulk samples.