Free-Space Extraction of Ultra-Long Anti-Diffracting Light Beam with Multiple Polarization Modes

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, i 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. 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.