Abstract

The intensity dependence of the reflectivity of plasmas produced by ultrashort-pulse (<1 ps), high-intensity lasers identifies the main processes in the physics of ultrashort-pulse plasma production. A number of measurements, ^1-5 have been made of the time-integrated reflectivity as a function of intensity with a variety of target materials, laser systems, and experimental conditions. None of these measurements, however, compares the reflectivity of materials with dramatically different electronic properties under identical experimental conditions. Our experiment measures the reflectivity of insulators (lithium fluoride, quartz), a semiconductor (silicon), and metals (aluminum, gold). Reflectivity curves in this variety of materials in conjunction with modeling give a more coherent picture of the main processes in the physics of plasma production.

© 1992 Optical Society of America