Optical vortices by an adaptive spiral phase plate

Abstract: An Adaptive Spiral Phase Plate (ASPP) based on liquid crystal (LC) and the transmission electrode technique is theoretically and experimentally demonstrated. This ASPP design enables the generation of high-quality optical vortices with topological charges ranging from $\pm1$ to $\pm4$ using a single device (but using a higher birefringence LC and thickness this number can be multiplied by four). The continuous reconfigurability of the optical phase shift, achieved through a simple control mechanism involving only two low voltages, sets this device apart as the most accurate approximation to an ideal ASPP proposed to date. This device offers remarkable advantages, such as complete reconfigurability, allowing adjustment of operating wavelengths and topological charges. The fabrication process mirrors that of a standard LCD cell, ensuring a cost-effective and reliable solution. Its versatile applications, including fiber optics communications and atom manipulation, promise reduced fabrication costs for existing devices and the generation of diverse Orbital Angular Momentum (OAM) modes. In summary, the proposed ASPP stands as a pivotal advancement, providing superior light efficiency, simplicity, and the capability for on-the-fly reconfiguration in a variety of optical applications.