Here we report a novel design of a heating laser for the fast ignition, combining fundamental and second harmonics lights. Such a two-colors laser is expected to heat a dense core more efficiently than a laser only with a fundamental light. We chose a LBO (LiB3O5) crystal which can convert a focusing beam due to its large acceptance of phase matching angle. We experimentally demonstrated the second harmonic conversion with efficiency of 60% at the maximum. The LBO crystal shows a high damage threshold more than 5 J/cm2 with a down-scale LFEX beams. A full size (10 cm×10 cm×2 mm) LBO crystal was manufactured completely and is ready to install for the full-scale LFEX operation.
|Country or International Organization||Japan|