Figure 10.

a) At a scattering angle away from the phase-matched direction, the travelling distances for the three mixing beams on either side of the spherical particle are slightly different, which yields a phase-shift across the particle diameter. The difference in traveling distance (δL) for the IR and visible beams is here illustrated for the two opposite sides perpendicular to the scattering angle; however, the integrated contributions from the particle surface has to be considered. b) The angular scattering pattern is dependent on factors such as particle size and shape, molecular orientation, and the angle between the excitation beams. A simulated pattern for achiral signals from spherical particles is shown, for which strong signals are precluded in the phase-matched direction (0°).