Substrate surface patterning by optical near field modulation around colloidal particles immersed in a liquid

Magdalena Ulmeanu, Petko Vladev Petkov, D. Ursescu, Robert L. Harniman, E. Brousseau, M. N. R Ashfold

    Research output: Contribution to journalArticlepeer-review

    71 Downloads (Pure)

    Abstract

    Optical near field enhancements in the vicinity of particles illuminated by laser light are increasingly recognized as a powerful tool for nanopatterning applications, but achieving sub-wavelength details from the near-field distribution remains a challenge. Here we present a quantitative analysis of the spatial modulation of the near optical fields generated using single 8 ps, 355 nm (and 532 nm) laser pulses around individual colloidal particles and small close packed arrays of such particles on silicon substrates. The analysis is presented for particles in air and, for the first time, when immersed in a range of liquid media. Immersion in a liquid allows detailed exploration of the effects on the near field of changing not just the magnitude but also the sign of the refractive index difference between the particle and the host medium. The level of agreement between the results of ray tracing and Mie scattering simulations, and the experimentally observed patterns on solid surfaces, should encourage further modelling, predictions and demonstrations of the rich palette of sub-wavelength surface profiles that can be achieved using colloidal particles immersed in liquids.
    Original languageEnglish
    Pages (from-to)27340-27351
    JournalOptics Express
    Volume24
    Issue number24
    Early online date28 Nov 2016
    DOIs
    Publication statusPublished - Dec 2016

    Fingerprint

    Dive into the research topics of 'Substrate surface patterning by optical near field modulation around colloidal particles immersed in a liquid'. Together they form a unique fingerprint.

    Cite this