Depolarization of Light in Optical Fibers: Effects of Diffraction and Spin-Orbit Interaction

Nikolai Petrov

doi:10.3390/fib9060034

Abstract

Polarization is measured very often to study the interaction of light and matter, so the description of the polarization of light beams is of both practical and fundamental interest. This review discusses the polarization properties of structured light in multimode graded-index optical fibers, with an emphasis on the recent advances in the area of spin-orbit interactions. The basic physical principles and properties of twisted light propagating in a graded index fiber are described: rotation of the polarization plane, Laguerre–Gauss vector beams with polarization-orbital angular momentum entanglement, splitting of degenerate modes due to spin-orbit interaction, depolarization of light beams, Berry phase and 2D and 3D degrees of polarizations, etc. Special attention is paid to analytical methods for solving the Maxwell equations of a three-component field using perturbation analysis and quantum mechanical approaches. Vector and tensor polarization degrees for the description of strongly focused light beams and their geometrical interpretation are also discussed.

Highlights

The polarization of light must be taken into account in many tasks of fiber optics communication and devices for coupling light in and from optical fibers
It is important to analyze the dynamics of the modes propagating in multimode fibers (MMFs)
The intensity distributions depend on the SAM and orbital angular momentum (OAM) of the incident beam

Summary

Introduction

The polarization of light must be taken into account in many tasks of fiber optics communication and devices for coupling light in and from optical fibers. The polarization state of light does not change during propagation in a homogeneous, isotropic, nondispersed medium [1,2]. Significant changes in the state and degree of polarization occur during propagation in an inhomogeneous medium and through optical fibers. Multimode optical fibers have attracted considerable interest in recent years for telecommunications, imaging, fiber lasers and amplifiers, ultrafast photonics, etc. They can operate over a wide range of wavelengths and have high coupling efficiency. They degrade weakly under the influence of nonlinear effects. It is important to analyze the dynamics of the modes propagating in multimode fibers (MMFs)

Objectives

Results

Discussion

Conclusion