Continuous wave frequency doubling of a high energy 1315 nm laser

A series of extracavity frequency doubling tests was performed using the 1315-nm output from RotoCOIL, a chemical oxygen-iodine laser (COIL). LiIO/sub 3/ was selected for the doubling medium due to its large nonlinear optical coefficient, its low absorption, and the availability of large crystals. Tests were performed for a variety of beam sizes using 1.1-cm and 2.2-cm crystals. Conversion efficiencies of 8% were achieved resulting in visible (657-nm) CW power levels of nearly 700 W. Catastrophic crystal failure occurred after a 1-s exposure to a focused beam of 6770 W.<
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