Nonlinear nearfield microscopy
Paper i proceeding, 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.

Författare

Annika Enejder

Chalmers, Kemi- och bioteknik, Molekylär mikroskopi

Juris Kiskis

Chalmers, Kemi- och bioteknik, Molekylär mikroskopi

Henning Hagman

Chalmers, Kemi- och bioteknik, Molekylär mikroskopi

Progress in Biomedical Optics and Imaging - Proceedings of SPIE

16057422 (ISSN)

Vol. 8588 858808

Styrkeområden

Nanovetenskap och nanoteknik

Materialvetenskap

Ämneskategorier

Fysik

Kemiteknik

Atom- och molekylfysik och optik

Nanoteknik

DOI

10.1117/12.2005002

ISBN

978-0-8194-9357-6