Nonlinear nearfield microscopy
Paper in proceedings, 2013

Higher-order nonlinearity of light-matter interactions, such as second and third harmonic generation (SHG & THG) and Coherent anti-Stokes Raman Scattering (CARS) can be used for improving spatial resolution in microscopy as a consequence of the confinement of the nonlinear polarization to the high-intensity region of the focal volume. However, the resolution is limited to similar to 300 nm, not sufficient to resolve macromolecules or nanostructures of interest in the bio-, life- and nano-sciences. In the strive to push the resolution beyond the diffraction limit, allowing for nanoscale imaging, we have equipped a nonlinear optical microscope with a scanning-probe setup operated in tapping-mode feedback. A tapered, gold-coated, open-aperture tip with an aperture diameter of similar to 150 nm is scanned over the sample, probing the nonlinear nearfield generated by free-beam excitation. First nonlinear coherent Raman nearfield images of biological macromolecules and metallic nanostructures are shown. Limitations and future challenges with nonlinear nearfield microscopy are discussed.

Author

Annika Enejder

Chalmers, Chemical and Biological Engineering, Molecular Imaging

Juris Kiskis

Chalmers, Chemical and Biological Engineering, Molecular Imaging

Henning Hagman

Chalmers, Chemical and Biological Engineering, Molecular Imaging

Progress in Biomedical Optics and Imaging - Proceedings of SPIE

16057422 (ISSN)

Vol. 8588 858808

Areas of Advance

Nanoscience and Nanotechnology (2010-2017)

Materials Science

Subject Categories

Physical Sciences

Chemical Engineering

Atom and Molecular Physics and Optics

Nano Technology

DOI

10.1117/12.2005002

ISBN

978-0-8194-9357-6

More information

Created

10/8/2017