Controllable extraction of arbitrary Poincaré-Bessel beams along propagation trajectory

Abstract

Poincaré spheres reveal the intimate relationship among the spin, orbital angular momentum, and states of polarization (SoPs) of light, playing a crucial role in diverse applications. However, generating Poincaré beams (PBs) whose single or multiple SoPs can be arbitrarily switched in space with a single input beam remains challenging, because conventional polarization-control schemes rely on a beat-interference mechanism that forces SoPs to evolve continuously along the propagation axis. Here, we demonstrate a phase-polarization joint strategy based on the principle of mode extraction (PoME) and an optical pen (OP) technique. By breaking the intrinsic modulation symmetry of a high-order vector vortex beam and harnessing polarization-mode competition among the liberated eigenmodes, our approach selectively amplifies a target polarization while naturally suppressing non-target components, achieving mode selection within a single incident beam without external polarization separation or recombination. Combined with the OP’s spatial-addressing capability, arbitrary PBs on both the fundamental and higher-order Poincaré spheres can be discretely and independently extracted at prescribed locations along the propagation path. We employ Bessel beams (BBs) for their diffraction-resistant and self-healing properties, which are well suited to long-distance SoP extraction. This work provides new perspectives for spatial polarization manipulation, with advantages in applications such as parallel laser manufacturing, high-dimensional optical quantum metrology, information encryption, and deep-biological imaging and sensing.