%0 Journal Article
	%A D.J. Brink and  N.G. van der Berg and  L.C. Prinsloo and  A. Botha
	%D 2009
	%J International Journal of Physical and Mathematical Sciences
	%B World Academy of Science, Engineering and Technology
	%I Open Science Index 33, 2009
	%T Broad-Band Chiral Reflectors based on Nano-Structured Biological Materials
	%U https://publications.waset.org/pdf/4809
	%V 33
	%X In this work we study the reflection of circularly
polarised light from a nano-structured biological material found in
the exocuticle of scarabus beetles. This material is made of a stack
of ultra-thin (~5 nm) uniaxial layers arranged in a left-handed
helicoidal stack, which resonantly reflects circularly polarized light.
A chirp in the layer thickness combined with a finite absorption
coefficient produce a broad smooth reflectance spectrum. By
comparing model calculations and electron microscopy with
measured spectra we can explain our observations and quantify most
relevant structural parameters.
	%P 603 - 607