Two-step etching method for fabrication of fibre probe for photon scanning tunneling microscope

The authors propose a novel two-step etching method for fabricating a fibre probe, with good reproducibility, for a photon scanning tunnelling microscope. A fibre probe with a cladding diameter of 14μm and cone angle of 20° was fabricated by adjusting the first-step etching time and the composition of the second-step etching solution.