Poster - Far-field Infrared Absorption Microscopy Beyond Diffraction Limit, Nanoweek Conference 2013, Ireland

This poster was presented at Nanoweek Conference 2013 in Dublin, Ireland. Summry of the poster is given below:

Far-field super-resolution infrared (IR) absorption micro-spectroscopy is investigated. More specifically, a pump-probe scheme where a first laser pulse exhibiting a central minimum pumps the vibrational population of a sample and where that population is probed with a second delayed pulse exhibiting a central maximum. The probe measures the IR absorption in the region where the pump is minimum and whose spatial extension is below the diffraction limit when the pump intensity exceeds the vibrational saturation threshold, in line with RESOLFT (REversible Saturable OpticaL Fluorescence Transition) schemes [1]. The super-resolution IR scheme was studied from a theoretical point of view to highlight reasonable expectations in terms of mid-IR compatible optical components, point-spread functions, spatial resolution, signal sensitivity, influence of pump-probe delay, and sample damage threshold [2]. It is found that probing the absorption of CH stretch modes at 3.5 μm is possible at a resolution of ca. 250 nm. The super-resolution scheme is currently studied on the basis of a mid-IR compatible confocal microscope and recent advances will be also presented.

Author: Christophe Silien, Syed A. M. Tofail, Ning Liu, Mahendar Kumbham, Isabel Pita 

Department of Physics and Energy, and Materials and Surface Science Institute, University of Limerick, Ireland

Author: André Peremans,  Nordine Hendaoui

Centre de Recherche en Physique de la Matière et des Rayonnements, Facultés Universitaires Notre Dame de la Paix, Namur, Belgium