Biomimetic all-organic near zero-index photonics inspired by photosynthetic photonic structures

Bioinspired photonics is rapidly advancing, leveraging nature's light-managing mechanisms to enhance sustainability, resilience, and processability in nanophotonic applications. A recent breakthrough in the field is the discovery of iridoplast, a chloroplast type with an efficient Bragg reflector structure that boosts light absorption through slow light effects. In this paper, we showcase how all-organic, metal-free photonic structures inspired by iridoplast exhibit optical properties that are thought to be unique to metals or complex oxide compositions. Firstly, we demonstrate that by replicating iridoplast using organic materials, a photonic crystal with Near-Zero-Index (NZI) properties is produced. We show experiments where the organic dye introduces strong absorptions, resulting in an NZI response and photonic stopbands that enhance light absorption in the VIS. Secondly, we show that, with the same materials but a different structure, it's possible to enable Optical Tamm States. Our results demonstrate that photosynthesis is a promising and yet poorly explored source of inspiration for sustainable photonics.