Electron excitation effect on scattering near-field and far-field ablation material processing by femtosecond laser irradiation

Taira Enami, Go Obara, Mitsuhiro Terakawa, Minoru Obara

研究成果: Article

1 引用 (Scopus)

抜粋

Femtosecond laser nano-processing by enhanced light scattered from nanospheres has received much attention. Enhanced scattered near field enables us to ablate nanoholes at nanometer scales below the diffraction limit. In addition, the interference between the scattered far field and the irradiated laser enables us to fabricate spatially controlled periodic surface structures. In this paper, we simulated the time evolution of scattered near field and far field during the free electron excitation in silicon (Si) by femtosecond laser irradiation. The optical property of Si changes from dielectric to metal-like Si due to the increase of the free electron number density excited by femtosecond laser pulse. It is elucidated that the scattered field of Si shifts from Mie scattering to plasmonic scattering during laser irradiation. We achieved the optimal free electron density and laser intensity for precisely controlled periodic surface structures fabrication. We explained the temporal behavior of the scattering near field and far field from the standpoint of dielectric function of the materials.

元の言語English
ページ(範囲)253-259
ページ数7
ジャーナルApplied Physics A: Materials Science and Processing
114
発行部数1
DOI
出版物ステータスPublished - 2014 1 1

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ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)

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