Search

To provide high-energy, high-power beams at short wavelengths for inertial-confinement fusion experiments, we routinely convert the 1.05-micrometer output of the Nova, Nd:phosphate-glass, laser system to its second- or third-harmonic wavelength. We describe the design and performance of the 3 x 3 arrays of potassium dihydrogen phosphate crystal plates used for type-II-type-II phase-matched harmonic conversion of the Nova 0.74-m diameter beams. We also describe an alternate type-I-type-II phase-matching configuration that improves third-harmonic conversion efficiency. These arrays provide conversion of a Nova beam of up to 75% to the second harmonic and of up to 70% to the third harmonic.

High-powered glass-laser systems with multiple beams, frequency-conversion capabilities, and pulse-shaping flexibility have made numerous contributions to the understanding of inertial confinement fusion and related laser-plasma interactions. The Nova laser at Lawrence Livermore National Laboratory is the largest such laser facility. We have made improvements to the Nova amplifier system that permit increased power and energy output. We summarize the nonlinear effects that now limit Nova's performance and discuss power and energy produced at 1.05-, 0.53-, and 0.35 micrometer wavelengths, including the results with pulses temporally shaped to improve inertial confinement fusion target performance.

We demonstrate temporal shaping of 0.35-[mu]m-wavelength pulses produced by a third-harmonic conversion of the output from the Nova Nd:phosphate glass-laser amplifier system for use in inertial confinement fusion experiments. We describe the computer models used to calculate the pulse shape that is required as the input to the amplifier system, the experimental apparatus used to produce these pulses, and the high-power 0.35-[mu]m shaped pulses produced in recent experiments.