Self-organization of surfaces on the nanoscale by topography-mediated selection of quasi-cylindrical and plasmonic waves

Nanophotonics

article

Anton Rudenko¹  Cyril Mauclair¹  Florence Garrelie¹  Razvan Stoian¹  Jean-Philippe Colombier¹ 

[1] University of Lyon, Institute of Optics Graduate School, Laboratoire Hubert Curien UMR 5516

关键词: nanoplasmonics;    ultrafast optics;    self-organization;    laser material processing;    surface waves;    ripples;   

DOI  :  10.1515/nanoph-2018-0206

学科分类：社会科学、人文和艺术（综合）

来源: De Gruyter

【 摘 要 】

Using coupled electromagnetic and hydrodynamic calculations, we elucidate theoretically the topographic transition from a random metallic surface to a periodic sub-wavelength grating by ultrashort laser ablation. The origin of this transition lies in the successive selection of hybrid surface waves scattered by random nanoholes. Contrary to the common belief that surface plasmon polaritons play the dominant role in the process and define the grating periodicity, we show that both quasi-cylindrical and surface plasmon waves are involved, whereas the diversity in the resulting spacings λ /2– λ ( λ is the laser wavelength) is the manifestation of a broad frequency overlap of these waves, controlled by their relative phase shifts with respect to the plasmonic counterparts. The topography evolution imposes the dominant contribution to the surface sub-wavelength pattern by selecting the appropriate wave character from plasmonic modes to evanescent cylindrical waves. With the radiation dose, the grating periodicity exhibits a pronounced blue shift due to reinforced dipole–dipole coupling between the nanoholes and surface curvatures in the laser-processed area. This allows the creation of regular patterns with tunable periodicity.

【 授权许可】

CC BY