Optical Sciences

Biomolecules and nanostructures

The Optical Sciences group studies the interaction of light and matter. Our current focus is on detection and sensing/imaging with an emphasis on the development of integrated photonics. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.


Measurement of a band-edge tail in the density of states of a photonic-crystal waveguide

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S.R. Huisman, G. Ctistis, S. Stobbe, A.P. Mosk, J.L. Herek, A. Lagendijk, P. Lodahl, W.L. Vos, and P.W.H. Pinkse
Physical Review B
vol. 86, issue 15, oct 26, 2012

We investigate light transport near the band edge of slow-light photonic-crystal waveguides using phasesensitive near-field microscopy. We obtain and interpret high-resolution band structures, allowing the retrieval of the optical density of states for a one-dimensional periodic system with weak intrinsic disorder. Because of this disorder, the band edge is smeared out and the van Hove singularity is removed. The density of states shows a decaying "tail" in the band gap corresponding to Anderson-localized modes, as predicted by Lifshitz for solid-state systems.
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