Fiber propagation of vector modes

TL;DR

This paper demonstrates the generation and measurement of vector vortex modes in optical fibers, analyzing their propagation, mode coupling, and non-separability, with implications for classical and quantum communication.

Contribution

It introduces a method for controlling and measuring fiber modes using phase manipulation and tomography, advancing mode division multiplexing techniques.

Findings

Successfully generated natural fiber modes with phase control

Measured modal cross-talk and non-separability decay

Showed potential for classical and quantum communication applications

Abstract

Here we employ both dynamic and geometric phase control of light to produce radially modulated vector-vortex modes, the natural modes of optical fibers. We then measure these modes using a vector modal decomposition set-up as well as a tomography measurement, the latter providing a degree of the non-separability of the vector states, akin to an entanglement measure for quantum states. We demonstrate the versatility of the approach by creating the natural modes of a step-index fiber, which are known to exhibit strong mode coupling, and measure the modal cross-talk and non-separability decay during propagation. Our approach will be useful in mode division multiplexing schemes for transport of classical and quantum states.