Microsphere-assisted super-resolution optical imaging of oriented silver nanowire arrays with polarized light

• Combining microsphere and polarization control enables advanced nanostructure imaging. • Polarized light reveals anisotropic optical properties of silver nanowires. • TE-polarized light improves visibility of silver nanowires compared to TM polarization. • Microsphere-assisted microscopy enhances resolution by a factor of 2 to 2.7. Microsphere-assisted microscopy is a label-free imaging technique capable of surpassing the diffraction limit of conventional optical microscopes. This study investigates the imaging of oriented silver nanowire (AgNW) monolayers as a function of incident light polarization using a 30 μm diameter microsphere. Two types of AgNW arrays, fabricated by a “bottom-up” technique and e-beam lithography, are analyzed. Using a home-built optical microscope, the relationship between microsphere magnification and image contrast is explored to identify the optimal position for maximum contrast. The developed optical setup demonstrates at least a twofold resolution enhancement and permits to effectively visualize the optical anisotropy of nanostructured samples by tuning the polarization of incident light. These findings highlight the potential for further improvements in microsphere-assisted microscopy to achieve superior nanoscale resolution. Topics: Microsphere-assisted microscopy, oriented silver nanowires, polarization, resolution enhancement.