Coherent anti-Stokes Raman scattering from small volumes

Abstract
We have used coherent anti-Stokes Raman scattering spectroscopy to resolve the Raman Q-branch line [Q(2) at 2987.18 cm−1] of dueterium gas contained in a 60-μm-diameter glass sphere. The 60-μm spheres contained only 10+13 molecules at standard temperature and pressure; this made it possible to study gases that in larger quantities would be too dangerous or expensive to use.