title: The thresholds of surface nano-/micro-morphology modifications with femtosecond laser pulse irradiations.
abstract: We studied the pulse energy threshold of surface nano-/micro-morphology modifications by irradiating Si, GaAs, GaP, InP, Cu and Ti surfaces with 100 fs laser pulses at a wavelength of 800 nm in air and in water. We found that the laser pulse energy thresholds required for the permanent modification in water are up to 30% lower than those in air. Different non-equilibrium dynamics processes of the surface melting layer cause the different thresholds in water and in air.
authors.affiliation: Department of Physics and Applied Physics, and Nanomanufacturing Center, University of Massachusetts Lowell, One University Avenue, Lowell, MA 01854, USA.
authors.forename: Cong
authors.initials: C
authors.lastname: Wang
authors.forename: Haibin
authors.initials: H
authors.lastname: Huo
authors.forename: Michael
authors.initials: M
authors.lastname: Johnson
authors.forename: Mengyan
authors.initials: M
authors.lastname: Shen
authors.forename: Eric
authors.initials: E
authors.lastname: Mazur