# Multi-twist optical Mobius strips

## TL;DR

This paper demonstrates that crossing circularly polarized laser beams create complex multi-twist Mobius strips in the polarization field, linked to Berry's phase, revealing new topological structures in optical fields.

## Contribution

It introduces a novel optical configuration producing multi-twist Mobius strips in polarization, connecting topological polarization structures with Berry's phase.

## Key findings

- Generation of multi-twist Mobius strips in polarization fields.
- Connection between polarization topology and Berry's phase.
- Observation of axial C lines in laser beam interference.

## Abstract

Circularly polarized Gauss-Laguerre GL(0,0) and GL(0,1) laser beams that cross at their waists at a small angle are shown to generate a quasi-paraxial field that contains an axial line of circular polarization, a C line, surrounded by polarization ellipses whose major and minor axes generate multi-twist Mobius strips with twist numbers that increase with distance from the C point. These Mobius strips are interpreted in terms of Berry's phase for parallel transport of the ellipse axes around the C point.