Staude, Isabellevon Freymann, GeorgWegener, Martin2016-05-132016-05-132159-3930http://hdl.handle.net/1885/101236Recent progress in three-dimensional sub-micron fabrication has rendered the introduction of waveguide structures into optical three-dimensional photonic bandgap materials possible. However, spectral tuning of the waveguide modes has not been demonstrated so far. Here, we use atomic-layer deposition of amorphous silica to tune the spectral position of an air-core defect waveguide in a three-dimensional silicon woodpile photonic crystal by 225 nm in wavelength. The measured spectral positions of the waveguide signature are in very good agreement with numerical calculations.We acknowledge support by the Deutsche Forschungsgemeinschaft (DFG) and the State of Baden-Wurttemberg through the DFG-Center for Functional Nanostructures (CFN) within sub- ¨ project A 1.4. The research of G.v.F. is further supported through a DFG Emmy-Noether fel-lowship (DFG-FR 1671/4-3). We acknowledge support by Deutsche Forschungsgemeinschaft and Open Access Publishing Fund of Karlsruhe Institute of Technology.© 2012 Optical Society of AmericaSpectral tuning of a three-dimensional photonic-bandgap waveguide signature by silica atomic-layer deposition201210.1364/OME.2.000629