Diode side pumped Nd: YAG slab laser with self-adaptive resonator

The novel scheme of self-adaptive, closed-loop resonator of diode-side-pumped Nd:YAG slab laser was presented. The dynamic holography principle was exploited to spatial cleaning of the laser mode. The phase conjugate mirror was created inside the gain medium as a result of four-wave mixing of resonator standing waves intersecting at a small angle. The output beam was extracted from the cavity as a 1-st diffraction order of laser mode interacting with the dynamic gain gratings created inside active medium. The near diffraction limited (parameter M-2 = 1.2) output beam with 250 mJ of energy at repetition rate up to 25 Hz in free running regime was achieved. Any spectral narrowing effects were not observed.