Optical sensing of ammonia using ZnO nanostructure grown on a side-polished optical-fiber

In this work, thin ZnO films were produced by pulsed laser deposition on a side-polished single-mode fiber in view of optical gas sensor applications. The experimental conditions used for preparation of the samples were chosen so as to obtain smooth, porous and nanostructured films. The influence of the film structure on the sensitivity to ammonia was investigated. For all samples, a shift of the spectral position of the resonance minimum to the longer wavelengths was observed under gas exposure at room temperature. The nanostructured sensor element demonstrated a substantially higher sensitivity due to its structure compared to the only smooth and porous samples.