Spatially resolved measurement of plasmon dispersion using Fourier-plane spectral imaging

We show that Fourier-plane imaging in conjunction with the Kretschmann–Raether configuration can be used for measuring polariton dispersion with spatial discrimination of the sample, over the whole visible spectral range. We demonstrate the functionality of our design on several architectures, including plasmonic waveguides, and show that our new design enables the measurement of plasmonic dispersion curves of spatially inhomogeneous structures with features as small as 3 μm, in a single shot.