Interplay of index contrast with periodicity in polymer photonic crystals

Christopher Edward Finlayson, Andrew I. Haines, David R. E. Snoswell, Andreas Kontogeorgos, Silvia Vignolini, Jeremy J. Baumberg, Peter Spahn, G. Peter Hellmann

Research output: Contribution to journalLetterpeer-review

26 Citations (SciVal)


We report how the strength of resonant Bragg reflection from polymeric photonic crystals (polymer opals) varies linearly with the refractive-index contrast, Δn, in contrast to the quadratic buildup of Fresnel reflections scaling as (Δn)2. This occurs due to the interplay of disorder and periodicity, in agreement with a simple 1-dimensional periodic model. Goniometry experiments show that opal films exhibit “cones” of resonantly scattered light, which extend to ±20° angular deviation from the specular direction. The intensity of the scattering cones varies super-linearly with Δn. Such medium contrast photonic crystals are of significant interest for understanding structural colors exhibited in nature, by structures with inherent disorder.
Original languageEnglish
Article number261913
JournalApplied Physics Letters
Early online date30 Dec 2011
Publication statusPublished - 2011


Dive into the research topics of 'Interplay of index contrast with periodicity in polymer photonic crystals'. Together they form a unique fingerprint.

Cite this