title: Symmetry-dependency of anticrossing phenomena in slab-type photonic crystals.
abstract: The optical properties of photonic crystals (PhCs) are strongly affected by their spatial symmetry characteristics. We observe anticrossing phenomena for large-area slab-type silicon PhCs sandwiched between a glass substrate and air. If a glass superstrate plus an index-matching fluid is added, thus establishing a mirror symmetry in z-direction, the anticrossing disappears. These characteristics are analyzed numerically using a finite-element Maxwell solver, and experimentally using large area samples made by nanoimprint lithography. We further discuss the findings by symmetry considerations.
authors.forename: Carlo
authors.initials: C
authors.lastname: Barth
authors.forename: Sven
authors.initials: S
authors.lastname: Burger
authors.forename: Christiane
authors.initials: C
authors.lastname: Becker