"In this thesis, an spatial mode analysis of a self adaptive holographic laser oscillator, ALO, formed by a nonlinear medium in a self intersecting loop geometry incorporating additional intracavity elements and a feedback mirror acting as output coupler, OC, is presented. An ABCD transfer matrix approach is used for the cavity elements as well as self-consistent steady-state solutions for the fundamental mode configuration. The study began by considering a simple ALO conformed by a plane OC and a nonlinear FWM, in the nonlinear medium in a self-intersecting geometry. The system was then modified to consider infinite and finite FWM media, and additional intra-loop optical elements, such as lenses and Gaussian trasnsmittance apertures."