Correlation of near‐field optical microscopy and tip‐assisted photoluminescence

Nanoscale optical imaging has unlocked unprecedented opportunities for exploring the structural, electronic, and optical properties of low‐dimensional materials with spatial resolutions far beyond the diffraction limit. Techniques such as tip‐enhanced, and tip‐assisted photoluminescence (TEPL and TAPL), as well as scattering‐type scanning near‐field optical microscopy (s‐SNOM) offer unique insights into local strain distributions, exciton dynamics, and dielectric heterogeneities that are inaccessible through conventional far‐field approaches, however their combination within the same setup remains challenging. Here we present the realisation of correlative TEPL/TAPL and s‐SNOM measurements within a single side‐illuminated near‐field optical microscope. We address the key experimental challenges inherent to the side‐illumination geometry, including precise laser focus alignment, suppression of far‐field background signals, and the mitigation of competing scattering pathways. Utilising monolayer WSe 2 as a model system, we demonstrate correlative imaging of material topography, strain‐induced photoluminescence shifts, and dielectric function variations. We visualise nanoscale heterogeneities on a bubble‐like structure, highlighting the complementary information from TAPL and s‐SNOM. This correlative approach bridges the gap between nanoscale optical spectroscopy and near‐field imaging, offering a powerful tool for probing local strain, doping, exciton behaviour, and dielectric inhomogeneities in low‐dimensional materials.