High efficiency TEM00 mode, diode-pumped, conduction-cooled, Nd:YAG zig-zag slab laser

We report a compact, conduction-cooled, highly efficient, continuous wave (CW) Nd:YAG slab laser in diode-side-pumped geometry. To achieve high efficiency, a novel laser head for Nd:YAG slab has been developed. For an absorbed pump power of 27.6 W, maximum output power of 10.4 W in multimode and 8.2 W in near-diffraction-limited beam quality has been obtained. Slope and optical-to-optical conversion efficiencies are 45.3% and 37.7% in multimode with beam quality factors (M²) in x and y directions equal to 32 and 8, respectively. TEM₀₀ mode operation was achieved in a hybrid resonator with slope and optical-to-optical conversion efficiencies of 43.2% and 29.7%, respectively. Beam quality factors in x and y directions are ?1.5 and ?1.6 for the whole output power range. The laser radiation was linearly polarized and polarization contrast ratios are >1200:1 in the multimode and 1800:1 in the TEM₀₀ mode operation. In passive Q-switching with Cr⁴⁺:YAG crystal of 68% initial transmission, 18 ns pulsewidth has been achieved with an average power of 2 W at a repetition rate of 16 kHz.