Investigation of wavefront reconstruction by a two-lens system

A two-lens system was used to obtain wavefront reconstruction (WFR) by stimulated Raman and Brillouin backscattering with the beam focus varied over a large range of distances. A fixed scattering object was placed between two lenses, and the focus of the two-lens system was varied continuously from near the second lens, through the image of the scattering object on to infinity by moving the first lens accordingly. In all prior experiments reported in literature the image of the object was formed beyond the lens focus. Images reconstructed by stimulated Raman and Brillouin backscattering were obtained and their positions and magnifications were in agreement with the holographic model.