3D-hyperspectral mapping of light propagation through diatom frustule silica nanostructures

Biological structures harvesting sunlight have evolved for several millions of years in different ways to optimize conversion efficiency. One of the most noteworthy examples of optical bio-nanostructures is the complex silica nanoporous frustule surrounding diatoms (unicellular algae). Diatoms have recently attracted significant attention for their potential in photonic applications. Coscinodiscus wailesii diatom frustules have been shown to combine photonic band gap and waveguide properties resulting in a wavelength dependent light focusing effect. Our experimental and computational results show the dependence between the spatial distribution of light transmitted through a single Coscinodiscus wailesii frustule and the wavelength. We used hyperspectral transmission mapping measurements to study the optical properties of single frustules of Coscinodiscus centralis (CC) and Coscinodiscus wailesii (CW) diatoms. Our aim is to provide a new insight on these properties using direct visualization of the light distribution after transmission through diatom frustules with different structures.