Fabrication of a triple tapered probe for near-field optical spectroscopy in UV region based on selective etching of a multistep index fiber

We propose a method to fabricate a novel triple tapered probe for highly sensitive and highly resolved near-field optical microscopy in a near ultraviolet region. The method is based on selective etching of a multistep index fiber. The obtained fiber probe has a triple tapered structure with three taper angles of 60 degrees, 120 degrees, and 60 degrees. With near-field optical microscopy employing the probe, we succeeded in obtaining a photoluminescence image of polysilanes excited by an ultraviolet laser with a wavelength of 351 nm. (C) 1998 Elsevier Science B.V.