Engineering wavefront caustics trajectories in ${\cal PT}$-symmetric lattices

TL;DR

This paper demonstrates how ${ m PT}$-symmetric lattices can be engineered to control wavefront caustics, enabling customizable focusing and beam trajectories with high intensity and aberration-free focal points at arbitrary distances.

Contribution

It introduces a method to design wavefront caustics in ${ m PT}$-symmetric lattices, leveraging gain and loss parameters for tailored intensity distributions and focal properties.

Findings

Achieved aberration-free focal points at arbitrary distances.

Controlled caustic trajectories with different intensity profiles.

Utilized gain/loss parameters to modify beam focusing characteristics.

Abstract

We utilize caustic theory in ${\cal PT}-$symmetric lattices to design focusing and curved beam dynamics. We show that the gain and loss parameter in these systems provides an addition degree of freedom which allows for the design of the same caustics trajectories with different intensity distribution in the individual waveguides. Moreover we can create aberration-free focal points at any paraxial distance $z_f$, with anomalously large focal intensity.