Coupling of Whispering Gallery Modes in Optical Fiber Resonators Based on Reflectionless Potential

Abstract

Photonic platforms combining the benefits of microscopic dimensions, flexibility, and control are of great interest due to the present and anticipated breakthrough capabilities in optical computing and communications. It was recently demonstrated that high-quality-factor traps for photons can be created in an optical fiber with nanoscale variation of an effective fiber radius [1, 2], which can account for the modification of both the fiber radius as well as the medium refractive index. Such fiber resonators function as surface nanoscale axial photonics (SNAP) devices, supporting whispering gallery modes (WGMs) which circulate near the fiber surface and slowly propagate in axial direction. The SNAP platforms enable precise control over the mode characteristics thanks to the record breaking sub-angstrom fabrication precision and ultralow scattering losses.