Transversal symmetry breaking and axial spreading modification for Gaussian optical beams

TL;DR

This paper reveals that the geometrical phase's second order term significantly influences Gaussian optical beam propagation, causing symmetry breaking and modifying axial spreading, highlighting its importance in accurate light behavior modeling.

Contribution

It demonstrates the crucial role of the geometrical phase's second order term in beam symmetry breaking and axial spreading, challenging previous assumptions of its insignificance.

Findings

Second order geometrical phase causes symmetry breaking in Gaussian beams.

The phase term acts as an axial spreading modifier.

Experimental implementation is discussed for validation.

Abstract

For a long time it was believed there was no reason to include the geometrical phase in studying the propagation of gaussian optical beams through dielectric blocks. This can be justified by the fact that the first order term in the Taylor expansion of this phase is responsible for the lateral shift of the optical beam which is also predicted by ray optics. From this point of view, the geometrical phase can be seen as a purely auxiliary concept. In this paper, we show how the second order term in the Taylor expansion accounts for the symmetry breaking of the transversal spatial distribution and acts as an axial spreading modifier. These new effects clearly shows the importance of the geometrical phase in describing the correct behavior of light. To test our theoretical predictions, we briefly discuss a possible experimental implementation.