Pristine spider silk fibers as waveguiding microstructure in free space and in an integrated photonic chip

Silk fibers produced by nature are among the most interesting materials. Besides their high degree of biocompatibility, they are bioresorbable, ecologically friendly, and offer excellent mechanical properties. In particular, silks of spider and worm have aroused a huge interest as seen by the large literature on their structural organization [1,2]. Thanks to material engineering possibility [3,4], regenerated worm silk has been intensively studied and used in different fields such as electronics and photonics [5,6]. On the other hand, native silks fibers are utilized in textile applications and in surgery procedures but have not yet deserved attention for photonic applications. However, the exceptional mechanical properties of natural silk mainly originate from an elaborated hierarchical organization which has not yet been reproduced in regenerated silk.