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Subwavelength Visualization Of Light In Thin Film Waveguides With Photoelectrons, Joseph P. Fitzgerald, Robert Campbell Word, Rolf Könenkamp

Physics Faculty Publications and Presentations

We report the visualization and quantitative analysis of electromagnetic surface fields at solid surfaces with the potential for λ/50 resolution. To illustrate this capability, we investigate patterns in two-photon photoemission images of light-diffracting structures in waveguiding, transparent thin films. The obtained micrographs show interference patterns between incident and guided light with a remarkable sensitivity to subwavelength features. We demonstrate that photoemission rates are directly related to the surface field strengths and develop a subwavelength method to calculate the surface fields from optical properties and surface topology based on the two-dimensional Kirchhoff diffraction integral. Calculated images based on this theoretical approach …