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 St okes gain for stimulated Raman gain experiments that use two crossed l aser beams. The laser beams are modeled as diffraction-limited, Gaussi an TEM(00) beams. Results for interaction length and relative Stokes g ain are presented for crossing angles of 0-15 degrees, focusingf/#'s 2 -250, and mismatches in the positions of the focal points of the two b eams. The numerical results for spatial resolution and gain are compar ed with geometric approximations that have been previously published. These numerical simulations show where the approximations are valid an d also extend into regions where the approximations are invalid. (C) 1 995 Optical Society of America