Influence of laser irradiation condition on a femtosecond laser-assisted tomographic atom probe

Influence of femtosecond laser pulse condition on the performance of an energy-compensated optical tomographic atom probe has been investigated. The unstable oscillator makes the mass peaks significantly broadened. Double 80 fs pulse train with 10 ns interval makes the mass peaks slightly shifted to the higher mass side. The mass peak shift corresponds to the fight time of ions triggered by laser pulsing. Chirping ratio for the laser pulses ranging from 80 fs to 10 ps is controlled by the pulse compressor for the fragile specimens such as oxide dispersion strengthen steel or insulator materials. A first-principle calculation for optical dielectric breakdown in diamond has been successfully demonstrated. It is shown that effective conductive increase has appeared at the laser intensity around 10(13)W/cm(2). (C) 2008 Elsevier B.V. All rights reserved.