title: Performance of a prototype for a large-aperture multipass Nd:glass laser for inertial confinement fusion.
abstract: The Beamlet is a single-beam prototype of future multibeam megajoule-class Nd:glass laser drivers for inertial confinement fusion. It uses a multipass main amplifier, adaptive optics, and efficient, high-fluence frequency conversion to the third harmonic. The Beamlet amplifier contains Brewster-angle glass slabs with a clear aperture of 39 cm x 39 cm and a full-aperture plasma-electrode Pockels cell switch. It has been successfully tested over a range of pulse lengths from 1-10 ns up to energies at 1.053 mum of 5.8 kJ at 1 ns and 17.3 kJ at 10 ns. A 39-actuator deformable mirror corrects the beam quality to a Strehl ratio of as much as 0.4. The 1.053-mum output has been converted to the third harmonic at efficiencies as high as 80% and fluences as high as 8.7 J/cm(2) for 3-ns pulses.
authors.forename: B M
authors.initials: BM
authors.lastname: Van Wonterghem
authors.forename: J R
authors.initials: JR
authors.lastname: Murray
authors.forename: J H
authors.initials: JH
authors.lastname: Campbell
authors.forename: D R
authors.initials: DR
authors.lastname: Speck
authors.forename: C E
authors.initials: CE
authors.lastname: Barker
authors.forename: I C
authors.initials: IC
authors.lastname: Smith
authors.forename: D F
authors.initials: DF
authors.lastname: Browning
authors.forename: W C
authors.initials: WC
authors.lastname: Behrendt