FABRICATION OF A PENCIL-SHAPED FIBER PROBE FOR NEAR-FIELD OPTICS BY SELECTIVE CHEMICAL ETCHING

We propose a novel method by chemical etching using hydrofluoric (HF) acid and a buffered HF solution (BHF) to fabricate a pencil-shaped fib er probe for near-field optics, We succeeded in producing such probes with high reproducibility using a dispersion-compensating fiber having the high GeO2 doped core, The method involves tapering of the claddin g, then sharpening of the core, The fabricated probe has a conical tip with a cone angle of 20 degrees and an apex diameter of less than 10 nm.