Waveguide-based microscope slide for label-free high-resolution imaging

Waveguide-based total internal reflection fluorescence microscopy has been widely adopted due to its excellent signal-to-noise ratio over a large field of view. However, with the increasing demand for label-free imaging, waveguide-based evanescent light scattering microscopy (ESM) has also garnered significant attention. Here, we present a low-cost waveguide-based microscope slide that offers easier integration with conventional optical microscopy. This microscope slide uses an incoherent light source coupled to a lithium tantalate (LT) planar waveguide to generate an evanescent light that illuminates samples located within a few hundred nanometers of the waveguide surface. We perform its application for imaging chromium nanoholes and polystyrene nanospheres, demonstrating its label-free, high-resolution, high-contrast imaging performance. LT waveguide microscope slides provide a simple and effective solution for ESM.