External design freedom for optimization of resonator originated beam shaping

Modern fabrication techniques like electron beam lithography allow the use of resonator mirrors with sophisticated surface modulation. We use this flexibility to realize a resonator with a beam the intensity distribution of which is specified in the focal region. The phase in the focal region is used as a freedom to homogenize the beam in the active medium and by that to allow the satisfaction of the laser gain condition. This is possible by a decoupling of the beam propagation characteristic of the beam inside and outside of the cavity. The design concept is described and experimentally demonstrated in a Nd:YAG laser.