We present a new way of measuring chirality, via the spectral shift of photonic band gaps in one-dimensional structures. We derive an explicit mapping of the problem of oblique incidence of circularly polarized light on a chiral one-dimensional photonic crystal with negligible index contrast to the formally equivalent problem of linearly polarized light incident on-axis on a non-chiral structure with index contrast. We derive analytical expressions for the first-order shifts of the band gaps for negligible index contrast. These are modified to give good approximations to the band gap shifts also in the case of appreciable index contrast. We believe that this may potentially be used for measuring enantiomeric excess.

Date Published: 1 September 2009
PDF: 7 pages
Proc. SPIE 7392, Metamaterials: Fundamentals and Applications II, 739208 (1 September 2009); doi: 10.1117/12.824870

Published in SPIE Proceedings Vol. 7392:
Metamaterials: Fundamentals and Applications II
Mikhail A. Noginov; Nikolay I. Zheludev; Allan D. Boardman; Nader Engheta, Editor(s)