Counting the optical cost of disorder in biological photonic systems

In this presentation, we review biological structurally coloured systems that, in particular, present ordered, quasi-ordered or disordered photonic structures. We discuss the nature of the optical behaviours of these structures, particularly focusing on the associated optical costs and benefits surrounding the extent to which their structures deviate from what might be considered ideal systems. We present detailed analyses of some well-known 1D and 2D structurally coloured systems and we analyse one of the common manifestations of imperfect order, namely, the extent and nature of positional disorder in the systems’ spatial distribution of layers and scattering centres. We describe how these findings are then used to inform optical modelling of the optical costs and benefits of such positional disorder among ordered and quasi-ordered 1D and 2D photonic systems. As deviation from perfectly ordered structures invariably limits the performance of technology- oriented synthetic photonic processes, we suggest that the use of bio-inspired fault tolerance principles would add value to applied photonic technologies.