<title>Trident as an ultrahigh irradiance laser</title>

Abstract

The Trident Nd:glass ICF laser at Los Alamos National Lab may be operated in a mode that produces high energy ultrashort pulses by the chirp/compression method. The 125-ps pulses from a standard mode-locked, Nd:YLF oscillator are first frequency-broadened to 3-nm bandwidth, chirped in a quartz fiber, and then compressed with a grating pair to 1.5 ps. A second quartz fiber then provides nonlinear polarization rotation for background and satellite suppression and to further broaden the spectrum to 4.5 nm. Pulses are chirped again to 500 ps width with a second grating pair and amplified in a Ti:sapphire regenerative amplifier pumped by frequency-doubled Nd:YAG. Millijoule-level output is then amplified through the existing phosphate glass Trident amplifier chain before compression to < 400 fs. Energy up to 1.5 J with excellent beam quality and contrast ratio is routinely produced by compressing after three rod amplifier stages. Higher energies are possible by compression further along the amplifier chain. Simultaneous use of long (approximately 1 ns) pulses for plasma formation is also possible.