skip to main content

Title: Plasmonic formation mechanism of periodic 100-nm-structures upon femtosecond laser irradiation of silicon in water

The formation of laser-induced periodic surface structures (LIPSS) upon irradiation of silicon by multiple (N = 100) linearly polarized Ti:sapphire femtosecond laser pulses (duration τ = 30 fs, center wavelength λ{sub 0} ∼ 790 nm) is studied experimentally in air and water environment. The LIPSS surface morphologies are characterized by scanning electron microscopy and their spatial periods are quantified by two-dimensional Fourier analyses. It is demonstrated that the irradiation environment significantly influences the periodicity of the LIPSS. In air, so-called low-spatial frequency LIPSS (LSFL) were found with periods somewhat smaller than the laser wavelength (Λ{sub LSFL} ∼ 0.7 × λ{sub 0}) and an orientation perpendicular to the laser polarization. In contrast, for laser processing in water a reduced ablation threshold and LIPSS with approximately five times smaller periods Λ{sub LIPSS} ∼ 0.15 × λ{sub 0} were observed in the same direction as in air. The results are discussed within the frame of recent LIPSS theories and complemented by a thin film based surface plasmon polariton model, which successfully describes the tremendously reduced LIPSS periods in water.
Authors:
; ; ;  [1] ; ;  [2]
  1. BAM Bundesanstalt für Materialforschung und –prüfung, Unter den Eichen 87, D-12205 Berlin (Germany)
  2. Max-Born-Institut für Nichtlineare Optik und Kurzzeitspektroskopie (MBI), Max-Born-Staße 2A, D-12489 Berlin (Germany)
Publication Date:
OSTI Identifier:
22314647
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 7; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ABLATION; AIR; FOURIER ANALYSIS; IRRADIATION; LASER RADIATION; LASERS; MORPHOLOGY; PERIODICITY; POLARIZATION; PULSES; SAPPHIRE; SCANNING ELECTRON MICROSCOPY; SILICON; SURFACES; THIN FILMS; TWO-DIMENSIONAL CALCULATIONS; WATER; WAVELENGTHS