Biotic photonics, trimming the optical properties of bioderived photonic nanostructures

The current climate urgency has triggered an ever-growing interest for biotic photonics, that is, use biological systems as inspiration or as source of biological-derived materials for technological applications. Photonics, as one of the most relevant but also contaminant technologies, requires a paradigm shift into more sustainable materials and less environmentally harmful fabrication processes. In this paper, we will present our recent advances into developing biotic photonics tackling part the challenge to shift photonics into a more sustainable technology. This work investigates the optical properties of diatom girdle bands as slab photonic crystals (sPhCs), leveraging their unique nanostructures for nanophotonic applications. We utilized scanning electron microscopy (SEM) to image the morphology of the girdle bands, enabling us to simulate and predict their photonic band structures and the spatial distribution of electromagnetic fields within the slab. Experimental characterization was conducted using back focal plane (BFP) image spectroscopy in epi-illumination, allowing for a detailed analysis of the optical behavior of the girdle bands. Furthermore, we successfully incorporated Rhodamine B (RhB) dye into the diatoms biosilica during its growth, obtaining preliminary data on the possible influence of the nanoporous architecture influences the dye's photoluminescence lifetimes within the spectral range between 561–750nm.