Improved performance of SPR sensors by a chemical etching of tapered optical fibers

We present the results of a chemical attack on the optical fiber surface previous to the deposition of the double layer (metal plus dielectric) in Double-layer uniform-waist tapered fibers (DLUWTs) used for the development of SPR sensors. It is shown how this simple chemical treatment increases the roughness of the surface and permits improvement of the stability of the deposits and the general performance of the sensors. The obtained devices are robust and very compact, their sensitivity is good and repeatability of the measurements is remarkably increased. The procedure can be useful for any fiber-optic sensor.

► Pre-processed tapered fibers with HF in vapor phase before deposition of a multilayer structure.
► Interaction surface of an optical fiber sensor increased through chemicaly induced roughness.
► No loss of sensitivity found after chemical etching of SPR-based tapered fiber sensors.
► Increase of long term stability of the fabricated transducers with the followed procedure.