Complete Localization of Light and Tunable Bottle Microresonators Introduced by Bending of an Optical Fiber

In this report, we present a method of fabrication of Surface Nanoscale Axial Photonic (SNAP) bottle microresonators [1] by strong bending of an optical fiber. We experimentally demonstrate that bending of the optical fiber causes the nanometer-scale variation of its local effective radius (ERV) along the fiber axis, which can lead to the complete localization of whispering gallery modes (WGMs) and formation of SNAP bottle microresonators. The simplicity of the introduced method and the ability to tune the induced ERV mechanically is of great importance for the fabrication of robust and tunable SNAP devices such as delay lines [2].