Open AccessBiologically enabled sub-diffractive focusing
Author(s) -
Edoardo De Tommasi,
Anna Chiara De Luca,
Luigi Lavanga,
Principia Dardano,
Mario De Stefano,
Luca De Stefano,
Carla Langella,
Ivo Rendina,
Kishan Dholakia,
Michaël Mazilu
Publication year - 2014
Publication title -
optics express
Language(s) - Uncategorized
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.22.027214
Subject(s) - optics , lens (geology) , structural coloration , photonics , stray light , diatom , photonic crystal , physics , biology , ecology
Evolution shows that photonic structures are a constituent part of many animals and flora. These elements produce structural color and are useful in predator-prey interactions between animals and in the exploitation of light for photosynthetic organisms. In particular, diatoms have evolved patterned hydrated silica external valves able to confine light with extraordinary efficiency. Their evolution was probably guided by the necessity to survive in harsh conditions of sunlight deprivation. Here, we exploit such diatom valves, in conjunction with structured illumination, to realize a biological super-resolving lens to achieve sub-diffractive focusing in the far field. More precisely, we consider a single diatom valve of Arachnoidiscus genus which shows symmetries and fine features. By characterizing and using the transmission properties of this valve using the optical eigenmode technique, we are able to confine light to a tiny spot with unprecedented precision in terms of resolution limit ratio, corresponding in this case to 0.21λ/NA.