Biocompatible silk step-index optical waveguides

Matthew B Applegate; Giovanni Perotto; David L Kaplan; Fiorenzo G Omenetto

doi:10.1364/BOE.6.004221

Biocompatible silk step-index optical waveguides

Biomed Opt Express. 2015 Oct 2;6(11):4221-7. doi: 10.1364/BOE.6.004221. eCollection 2015 Nov 1.

Authors

Matthew B Applegate¹, Giovanni Perotto¹, David L Kaplan¹, Fiorenzo G Omenetto²

Affiliations

¹ Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA.
² Department of Biomedical Engineering, Tufts University, 4 Colby Street, Medford, MA 02155, USA ; Department of Physics, Tufts University, 4 Colby Street, Medford, MA 02155, USA.

Abstract

Biocompatible optical waveguides were constructed entirely of silk fibroin. A silk film (n=1.54) was encapsulated within a silk hydrogel (n=1.34) to form a robust and biocompatible waveguide. Such waveguides were made using only biologically and environmentally friendly materials without the use of harsh solvents. Light was coupled into the silk waveguides by direct incorporation of a glass optical fiber. These waveguides are extremely flexible, and strong enough to survive handling and manipulation. Cutback measurements showed propagation losses of approximately 2 dB/cm. The silk waveguides were found to be capable of guiding light through biological tissue.

Keywords: (160.1435) Biomaterials; (160.5470) Polymers; (170.3890) Medical optics instrumentation; (230.7370) Waveguides.