Alcohol vapors sensitivity of a device based on a single mode optical fiber end-face coated with a thin zinc oxide
(ZnO) film is presented. The overlays were deposited by Atomic Layer Deposition (ALD) method on both optical
fiber tips and silicon reference wafers, and subsequently characterized by means of spectroscopic ellipsometry and
scanning electron microscopy. It has been found that the ZnO films show very high quality and they are conformal
over the surfaces. The thin ZnO film forms a Fabry-Perot interferometer at the fiber end-face which properties change
when the tip is exposed to alcohol vapors. The response of the structure to isopropanol vapors is shown and discussed
for different thickness of the ZnO film