Exchangeable scanning probe microscopy optical fiber tips

Correlative probe, electron, and near-field cathodoluminescence (CL) microscopy in scanning electron microscope (SEM) enables comprehensive sample characterization and chemical analysis, which are crucial for advancing novel material and nanotechnology research. In this technique, scanning near-field optical microscopy (SNOM) probe scans the sample simultaneously with the electron beam, enabling the acquisition of correlated images. However, the system's added complexity and the fragility of the implemented SNOM tip have yet limited the widespread adoption of this powerful technique combination. Here, we present a newly developed self-sensing quartz-based probe for the AFM-in-SEM solution LiteScope™. This probe features an optical fiber with an exchangeable tip designed to address the tip fragility. This innovative probe-tip system allows seamless in situ SEM replacement of only the fragile tip at the optical fiber’s end, without venting the vacuum chamber and replacing the entire probe. These exchangeable tips are fabricated in a stack on a silicon wafer using two-photon polymerization (TPP) and subsequently undergo post-process plasma etching to achieve an apex of elliptical cross-section with a semi-minor axis of 24 nm. Proof-of-concept CL and topography measurements are presented. The described socket for mounting the SNOM tip on the optical fiber is readily applicable to accommodate various other TPP 3D printable optical fiber terminations, such as micro-optical and mechanical elements, and sensors. The presented solution not only streamlines the workflow of the correlative probe, electron, and near-field CL microscopy but also broadens the applicability of optical fiber functionalization for diverse experimental setups.