Optical fiber sensors fabricated by the focused ion beam technique

Focused ion beam (FIB) is a highly versatile technique which helps to enable next generation of lab-on-fiber sensor technologies. In this paper, we demonstrate the application of FIB to precisely mill the fiber taper and end facet of both conventional single mode fiber (SMF) and photonic crystal fiber (PCF). Using this technique we fabricate a highly compact fiber-optic Fabry-Perot (FP) refractive index sensor near the tip of a fiber taper, and a highly sensitive in-line temperature sensor in a PCF. We also demonstrate the potential of using FIB to selectively fill functional fluid into desired patterns of air holes in a PCF.