Infrared Nanoscopy: Going Beyond the Diffraction Limit on a Tabletop Instrument

<align="center">S. A. M. Tofail¹, A. Peremans², C. Silien¹ <align="center">  <align="center">¹ Department of Physics and Energy, and Materials and surface Science Institute, University of Limerick, Limerick, Ireland <align="center">² Department of Physics, Facultés Universitaires Notre-Dame de la Paix, Namur, Belgium <align="center">Email: Tofail.Syed@ul.ie; fp7LANIR@ul.ie Abstract: The ability to image molecular building blocks in ambient conditions is critical to advance our understanding of cellular and sub-cellular biological processes and industrial quality control for nano-enabled products. While far field vibrational spectroscopies such as infra-red (IR) absorption, is capable of revealing the chemical structure currently spatial resolution with these techniques are limited by diffraction even when using a synchrotron source. The near-field approach, while offers high spatial resolutions, is limited to providing surface information only and currently impractical for real life applications in clinical diagnosis and industrial metrology. Far field IR absorption has gained wide popularity for its simplicity and the ability of finger-printing through chemical signatures. As its sensitivity is much higher than Raman scattering based techniques, far field IR is very appealing for nanoscale real time imaging provided that the diffraction limit is overcome. We will present a few breakthrough developments of infrared nansocopy using a far-field, table-top Nanoscope that breaks away from the diffraction barrier of infrared imaging [1-3]. Acknowledgements: The LANIR research leading to these results has received funding from the European Community's Seventh Framework Programme (FP7/20012-2015) under grant agreement n°280804. This communication reflects the views only of the authors, and the Commission cannot be held responsible for any use which may be made of the information contained therein.   [1] www.lanir.eu [2] Silien, C., Liu, N., Hendaoui, N., Tofail, S.A.M., Peremans, A., 2012. A framework for far-field infrared absorption microscopy beyond the diffraction limit, Optics Express. 20, 29694-29704.

[3] Pita, I., Hendaoui, N., Liu, N., Kumbham, M., Tofail, S.A.M., Peremans, A. and Silien C. 2013. High resolution imaging with differential infrared absorption micro-spectroscopy, Optics Express, 21, 25632-25642