Long-Term Hydrogen Detection Using a Hetero-Core Optical Fiber Structure Featuring Au/Ta₂O₅/Pd/Pt Multilayer Films

Abstract

We introduce a Pt-coated, hetero-core, optical fiber-surface plasmon resonance (SPR) hydrogen sensor featuring layers of Au/Ta <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> /Pd for long-term hydrogen detection. Hydrogen sensing persisted after 1- and 2-month storage at room temperature in air conditioning. To test the effect of Pt coating, sensors coated with Au and Pd-only-based optical fiber hydrogen sensors were prepared. Sensors coated with a thin Pt film were superior to sensors coated with Au/Ta <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> /Pd or Au/Ta <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">5</sub> /Pd/Au multilayer films with respect to the suppression of sensor sensitivity- and response time deterioration.