Tittl, AndreasAndreasTittlKremers, ChristianChristianKremersDorfmüller, JensJensDorfmüllerChigrin, Dmitry N.Dmitry N.ChigrinGiessen, HaraldHaraldGiessen2026-03-112026-03-112012-02-01Optical Materials Express 2 (2): 111-118 (2012)https://hdl.handle.net/11420/61996In this work, we numerically investigate the nature of spectral shifts in antenna-enhanced hydrogen sensing geometries consisting of a gold bowtie antenna next to a palladium nanodisk. We find through extensive finite element (FEM) simulations that the hydrogen-induced spectral behavior of the system is governed by two competing effects: a small blueshift caused by dielectric function changes in the palladium and a much stronger redshift due to an expansion of the palladium lattice. Our findings enable the accurate numerical characterization and especially the optimization of sensitive antenna-enhanced hydrogen sensors. As a first application, we calculate the performance improvement of gap antennas compared to single cut-wire antenna elements. © 2012 Optical Society of America.en2159-393020122111118Technology::600: TechnologyJournal Article10.1364/OME.2.000111