High-NA 2D\nImage Edge Detection Using Tamm Plasmon\nPolaritons in Few-Layer Stratified Media

Analog optical computing\nwith nanophotonic devices has\nemerged\nas a promising solution to the need for ultrafast computation with\nlow power consumption. Several key mathematical operations, including\nspatial derivatives for edge detection, have recently been demonstrated.\nHowever, these initial approaches are typically characterized by a\nsmall numerical aperture (NA), strong polarization dependence, narrow\noperational bandwidths, or the need for complex nanofabrication procedures.\nHere, we demonstrate how a very simple 7-layer thin-film stack provides\ndual-channel, high efficiency, polarization-independent 2D edge detection\nwith a numerical aperture approaching 0.9, by leveraging the intrinsic\nproperties of Tamm plasmon polariton resonances. By engineering the\nresonant decay rates, we propose simple design rules for the layer\nstack to achieve high-efficiency edge detection with a NA that matches\nthe desired spatial resolution. Using this, we experimentally demonstrate\nedge detection of micrometer-scale targets with a bandwidth reaching\nup to 10 nm, enabling operation under filtered, unpolarized, and low-coherence\nillumination from a halogen lamp. Our results push optical image edge\ndetection toward a wider range of practical applications, including\nhigh-resolution microscopy.