Talbot effect in nanostructured diatom frustules

The study of light propagation in hierarchically structured materials offers insights into novel, to our knowledge, optical phenomena. These materials, with intricately organized architectures spanning various length scales, demonstrate remarkable light manipulation through complex scattering, diffraction, and interference. Diatom frustules, the silica-based cell walls of diatom algae, exemplify such materials with their nanostructured shells having quasiperiodic arrays of holes. This research explores the optical properties of Coscinodiscus oculus-iridis through numerical simulations using the Fourier modal method in scattering matrix form. We studied transmittance and reflectance for single- and double-valve periodic structures as a function of wavelength and angle of incidence. Our simulations reveal how the spatial distribution of solar radiation energy within frustules varies with depth, wavelength, and angle, demonstrating local enhancement of absorption due to the Talbot effect. The results underscore the interplay between the frustule 3D structure and light, uncovering mechanisms behind efficient light trapping in diatoms. The synergy between the Talbot effect and chloroplast distribution emphasizes the adaptive advantages of diatoms in light-limited environments, providing insights into their ecological success and potential applications in bioengineering, photonic devices, and light-harvesting technologies.