ND-YAG LOOP RESONATOR WITH A CR4-PUMPED PHASE-CONJUGATE MIRROR(YAG SELF)

We demonstrate a Nd:YAG loop resonator with a self-pumped phase conjug ate mirror in a Cr4+:YAG crystal, in the nanosecond regime. A maximum extraction of 29 mJ and a maximum reflectivity of 3.3 are obtained. Th e output beam is a high-quality diffraction-limited TEM(00) mode and h as a pulse shape of similar to 20-ns duration, showing the self Q-swit ching ability of the resonator. In addition, we demonstrate an origina l and specific configuration of the anisotropic Cr4+:YAG crystal that compensates not only for phase aberrations but also for polarization a berrations induced into the loop resonator.