Measuring the full vectorial nature of light on the nanometer scale

01.01.2014, 00:00

Newsletter 7

Tightly focused light beams with tailored field distributions find a wide range of applications in nano-optics, microscopy and imaging. Precise knowledge of such field distributions is of utmost importance. Measuring the fully vectorial distribution of the electric field of an optical wave is not an easy task, especially in the diffraction-limited focal spot of a high numerical aperture system. This is due to the deep sub-wavelength features exhibited by such a field distribution. We have demonstrated an experimental method and a theoretical analysis algorithm for measuring the three-dimensional field structure of highly confined light. This technique, which we call "Mie scattering nanointerferometry", relies on angularly resolved measurement of the light scattered at a single plasmonic nanoparticle utilized as a scanning field probe (see figure). The interference between scattered and incoming light allows precise determination of the amplitude and relative phase distributions of all individual electric field components, hence providing detailed insight into the fully vectorial nature of the field distribution under study. No complex analysis of the scattered light field in terms of its polarization is required. This high resolution technique is easy-to-implement and highly compatible with standard microscopy systems.

Contact: peter.banzer(at)mpl.mpg(dot)de
Group: Leuchs Division
Reference: T. Bauer et al., Nature Photonics 8, 23–27 (2014).