INTERACTION GEOMETRIES OF SELF PUMPED PHASE-CONJUGATING SBS CELLS

Focused beam SBS cells and waveguide geometry are compared expanding the light wave into transverse modes, allowing for an analytical discussion. Waveguides give poor fidelity when used without aberrators to homogenize the intensity distribution over the light pipe cross section. Focused beam SBS cells can phase-conjugate single transverse mode pump waves without the help of aberrators. The calculated fidelity of about 0.6 for pumping with the fundamental mode is nearly constant from threshold up to more than 70% reflection. The beam constriction factor is β=0.7 resulting in a 1.4-times diffraction limited reflected beam.