title: Direct measurement of the near-field super resolved focused spot in InSb.
abstract: Under appropriate laser exposure, a thin film of InSb exhibits a sub-wavelength thermally modified area that can be used to focus light beyond the diffraction limit. This technique, called Super-Resolution Near-Field Structure, is a potential candidate for ultrahigh density optical data storage and many other high-resolution applications. We combined near field microscopy, confocal microscopy and time resolved pump-probe technique to directly measure the induced sub-diffraction limited spot in the near-field regime. The measured spot size was found to be dependent on the laser power and a decrease of 25% (100 nm) was observed. Experimental evidences that support a threshold-like simulation model to describe the effect are also provided. The experimental data are in excellent agreement with rigorous simulations obtained with a three dimensional Finite Element Method code.
authors.affiliation: Optics Research Group, Department of Imaging Science and Technology, Delft University of Technology, Lorentzweg 1, 2628 CJ Delft, The Netherlands. a.dacostaassafrao@tudelft.nl
authors.forename: A C
authors.initials: AC
authors.lastname: Assafrao
authors.forename: A J H
authors.initials: AJ
authors.lastname: Wachters
authors.forename: M
authors.initials: M
authors.lastname: Verheijen
authors.forename: A M
authors.initials: AM
authors.lastname: Nugrowati
authors.forename: S F
authors.initials: SF
authors.lastname: Pereira
authors.forename: H P
authors.initials: HP
authors.lastname: Urbach
authors.forename: Marie-Francoise
authors.initials: MF
authors.lastname: Armand
authors.forename: Segolene
authors.initials: S
authors.lastname: Olivier
mesh_terms: D000965:Antimony / Q000737:chemistry* / Q000528:radiation effects*; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007204:Indium / Q000737:chemistry* / Q000528:radiation effects*; D007834:Lasers; D007909:Lenses
chemical_list: D007204:Indium; D000965:Antimony