High-efficiency, high-power difference-frequency generation of 0.9-1.5 μm light in BBO

An efficient method for generation of high energy pulsed ir light between 0.9 and 1.5 ltm is described. The technique uses difference frequency mixing of pulsed, visible dye and Nd:YAG laser light in a 10 mm long BBO crystal. Quantum efficiencies of up to 23% and ir pulse energies up to 4.5 mJ are demonstrated. The low shot-to-shot fluctuations of difference frequency generation in BBO make this technique an attractive alternative to the conventional optical parametric oscillator or Raman shifting methods that are currently used to access this spectral region.