Nanophotonics of optical fibres

10 01/2014

Friday, 10 Jan. 2014, 15:30 - 16:30

Workgroup Rauschenbeutel Group

Presenter: Misha Sumetsky
Host: Arno Rauschenbeutel
Where: Hörsaal Atominstitut

Nanoscale effects in highly transparent dielectric photonic structures fabricated from optical fibres are reviewed. In contrast to those in plasmonics, these structures do not contain metal particles, wires, or films with nanoscale dimensions. Nevertheless, a nanoscale perturbation of the fibre radius can significantly alter their performance. In the first part of this presentation, propagation of light in thin optical fibres (microfibers) having the radius of the order of 100 nanometres to 1 micron is considered. The fundamental mode propagating along a microfiber has an evanescent field which may be strongly expanded into the external area. Then, the cross‐sectional dimensions and structure of the mode and transmission losses strongly vary with nanoscale variations of the microfiber radius. In the second part of the presentation, slow propagation of whispering gallery modes in fibres having the radius of the order of 10 to 100 microns is considered. The propagation of these modes along the fibre axis is so slow that they can be governed by extremely small nanoscale changes of the optical fibre radius. This phenomenon is exploited in SNAP (Surface Nanoscale Axial Photonics), a new platform for fabrication of miniature super‐low‐loss photonic integrated circuits with unprecedented sub‐ angstrom precision. The SNAP theory and applications are overviewed.