Shaping the reflection near‐field optical probe: finite domain time difference modelling and fabrication using a focused ion beam

An optical fibre ending in a trihedral tip is proposed as a convenient probe for reflection near‐field optical microscopy in emission/collection mode. Its shape is obtained by ion milling. A first example of manufacturing and numerical models using the bi‐dimensional FDTD method is presented. It confirms the strong influence of the facet angle on the intensity reflected by the probe, which is predicted by a rough analysis. This method can help us to optimize the ‘reflection probe’ by reducing this offset signal.