Manipulation of polarization topology using a Fabry–Pérot fiber cavity with a higher-order mode optical nanofiber

Abstract

Optical nanofiber cavity research has mainly focused on the fundamental mode. Here, a Fabry–Pérot fiber cavity with an optical nanofiber supporting the higher-order modes (TE01, TM01, HE21 o , and HE21 e ) is demonstrated. Using cavity spectroscopy, with mode imaging and analysis, we observed cavity resonances that exhibited complex, inhomogeneous states of polarization with topological features containing Stokes singularities such as C-points, Poincaré vortices, and L-lines. In situ tuning of the intracavity birefringence enabled the desired profile and polarization of the cavity mode to be obtained. We believe these findings open new research possibilities for cold atom manipulation and multimode cavity quantum electrodynamics using the evanescent fields of higher-order mode optical nanofibers.