Free-space extraction of ultra-long anti-diffracting light beam with multiple polarization modes

Abstract

Polarization modulation, the key to human-driven light, plays an important role in determining imaging resolution and contrast, the capacity and security of optical communications, as well as the precision of target detection and recognition. However, customizing multiple polarization modes within a single beam simultaneously and specifically remains a challenge. To address this issue, we developed a method to extract tunable polarization modes along the trajectories of ultra-long anti-diffracting Airy beams with multiple energy oscillations from an m-order vector vortex beam. This approach allows for the arbitrary definition and switching of multiple on-demand polarization mode along the propagation direction (z-direction) using mode extraction and an optical pen without altering the polarization state of the incident beam. Without superimposing at least two incident polarization modes, polarization modes in different transmission trajectories can be extracted directly from the high-order vector vortex beam based on the principle on mode extraction. The number, position, amplitude and phase of polarization mode can further be arranged in an arbitrary manner with the aid of optical pen. The tunable polarization modes along the z-direction are of particular interest to researchers in the fields of particle trapping, large-depth imaging, optical communication, electronics and acoustics.