All-fiber polarization/spatial mode rotator based on geometric effects

Abstract

All-fiber wavelength-independent polarization rotator based on geometric effects is introduced and demonstrated with a novel design. The geometric phase or Berry phase can cause the polarization rotation in the optical fiber, but bend-induced birefringence exists in the fiber. All-fiber wavelength-independent polarization rotator is designed with self compensating the bend-induced birefringence. It consequently provides the wavelength-independent operation. Polarization rotator is demonstrated for fixed angle and angle-tunable function both and especially reflector-type fixed polarization rotator is analyzed in comparison with mirror, Faraday rotation mirror, Sagnac loop mirror. The possibility of applying the structure of the suggested polarization rotator to a spatial mode rotator is finally investigated.