The development of platinum iridium probe for low temperature near-field microscope

Abstract

In this study, we developed the platinum iridium probe to improve the SN ratio of a low-temperature terahertz scanning near-field optical microscope. Comparing to tungsten for a conventional scanning probe, the platinum iridium is stable for oxidization and can provide a probe with high scattering performance for nearfield wave. We carried out electrolytic polishing to sharpen the platinum iridium fine wire and obtained the probe with a tip radius of approximately 50 nm. To evaluate the fabricated probe, we demonstrated detecting near-field signals on a gold film at room temperature, which showed the probe had equivalent performance with a conventional tungsten probe.