Measurements of subpicosecond laser-produced plasmas

Abstract

We describe the design of a high power subpicosecond UV laser and report its use in a study of the characteristics of short-lived laser-induced plasmas. The laser consists of a mode-locked dye laser, synchronously pumped by a mode-locked argon-ion laser. The dye laser operates at 616.0 nm and is cavity-dumped, with the output pulses sent to a fiber-grating compressor. The resulting pulses are <500 fs in duration. These pulses are amplified in a series of Nd:YAG-pumped dye amplifiers, doubled in KD*P, and sent through two XeCl excimer amplifiers. Typical output pulses exceed several millijoules with <1-ps FWHM duration, yielding focused intensities of 1015W/cm2 on various targets. Plasma diagnostics include a grazing incidence monochromator, an x-ray streak camera, and particle detector. Additionally, we describe several novel methods for measuring subpicosecond plasma emissions in the x-ray and visible/IR spectral regions.