Optical nanofibers, also known as nanoscale optical waveguides or nanowires, represent a fascinating class of optical structures with diameters typically on the order of hundreds of nanometers to a few micrometers. These ultrathin fibers, usually made of dielectric or semiconductor materials, exhibit remarkable optical properties that make them versatile platforms for fundamental research and various applications. Whispering-gallery-mode (WGM) resonators are conceptually and technologically closely linked to optical nanofibers because of their shared principle of strong light confinement through total internal reflection, which leads to the formation of evanescent fields that extend beyond the surface of the structure. For this reason, nanofibers and WGM resonators also share many fields of application, ranging from photonics, to quantum optics, to sensing and metrology, to nonlinear optics and frequency conversion, to opto-mechanics.
The last two decades have seen a steady increase in interest and in the size and cohesiveness of the community surrounding optical nanofibers and WGM resonators. This can be attributed to advances in fabrication techniques, a growing understanding of light-matter interactions, the diverse range of applications, and emerging technologies and challenges. At the same time, other nanophotonic platforms and their use in research and applications are also developing rapidly, often inspired by pioneering work with nanofibers and whispering gallery mode resonators. This seminar will bring together experts in (quantum) nanophotonics research and applications to assess the current state of this rapidly evolving interdisciplinary field and to discuss future developments. It will provide a high-profile venue to meet and discuss with the leaders in the field, as well as to promote its relevance and potential to the next generation of researchers.