Generation of chaotic vector vortex beams with dual parallel dielectric metasurfaces

Chaotic laser has attracted intensive attention because of its distinctive temporal and spectral properties. Incorporating additional spatial degrees of freedom, such as phase and polarization, is expected to enhance its suitability for high-security and high-speed optical communications. Here, we report a feasible conjoint method for the generation of chaotic vector vortex (CVV) beams. To achieve this, we first build the optical feedback experimental platform to yield a broadband chaotic laser. By further engineering two parallel dielectric Pancharatnam-Berry (PB) metasurfaces, we map orthogonal circularly polarized components into distinct vortex modes and coherently superpose them. As a result, we succeed in producing the CVV beams with various orders by integrating the optical feedback module with the dual PB metasurfaces. Notably, the CVV beams not only maintain the randomness of the chaotic laser but also exhibit unique spatial characteristics. As a proof of concept, we securely deliver two images through two scheduled channels at a communication rate of 5 Gbit/s per channel and a signal-to-noise ratio of 11.5 dB under crosstalk conditions, thus demonstrating the confidential and multiplexing capability of CVV beams. The CVV beams combine large bandwidth, strong security, and high integration potential, providing a new pathway for capacity scaling in chaotic secure communications.