The role of laser wavelength on the early-stage electron density evolution in laser-produced plasma

Abstract

This study compares the role of laser wavelength on the early time electron density evolution of the plasma following laser ablation using Nomarski interferometry. The laser-produced plasma was generated by focusing fundamental (1064 nm), second (532 nm), and fourth (266 nm) harmonic radiation from a 6 ns Nd:YAG laser at a laser intensity of 10 GW/cm 2 onto a copper target placed in vacuum. The dependence of plasma properties such as the electron density distribution, plume velocity, and plume morphology on the laser wavelength are discussed.