Effect of crossed beams on Stokes gain and interaction length in stimulated Raman gain spectroscopy.

We have numerically calculated the change in spatial resolution and Stokes gain for stimulated Raman gain experiments that use two crossed laser beams. The laser beams are modeled as diffraction-limited, Gaussian TEM(00) beams. Results for interaction length and relative Stokes gain are presented for crossing angles of 0-15°, focusing ƒ/#'s 2-250, and mismatches in the positions of the focal points of the two beams. The numerical results for spatial resolution and gain are compared with geometric approximations that have been previously published. These numerical simulations show where the approximations are valid and also extend into regions where the approximations are invalid. PACS: 42.65 Dr.