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Results are presented on a high power, diode-pumped, pulsed Nd:YAG laser for precision laser machining. The laser is an unstable resonator with a graded reflectivity outcoupler, generating a beam with excellent beam quality. The gain medium is a single zig-zag slab, pumped symmetrically by diode arrays. The use of diode arrays minimizes the thermal loading on the slab, and the zig-zag path averages thermal distortions in the zig-zag dimension. Measurements of beam divergence as a function of diode duty-cycle will be presented. Available pulse formats will also be discussed. To date, the laser has produced 720 W at 20% diode duty-cycle with a stable cavity and 550 W at 20% duty cycle with an unstable cavity in close agreement with model predictions. The beam divergence has been measured to be 1.7 times diffraction-limited at 20% duty cycle. The laser has been operated with pulse lengths from 20 μs to 1 ms and is being used to obtain laser processing data, with some results shown.

We report ab initio configuration interfaction calculations on the states of the gallium krypton (GaKr) molecule arising from the Ga(2P1/2,3/2,2S1/2) + Kr(1SO) and Ga+(1SO) + Kr(1SO) separated atom limits. The potential energy curves for the states arising from the Ga(2P1/2,3/2) limits, the I 1/2, II 1/2, and I 3/2 states, are found to be repulsive. The potential energy curves for the states arising from the Ga(2S1/2) and Ga+(1SO) limits, the III 1/2 and I 0 states, are both found to be weakly bound; De (III 1/2) = 0.047 eV and D (I 0) = 0.24 eV. The potential energy curves and transition moments obtained in the GaKr calculations have been used to simulate the curves and moments for InKr and TlKr. Using this data the absorption and emission coefficients of all three molecules have been calculated.