Orbital angular momentum of an elliptic beam after an elliptic spiral phase plate

Color image information transmission based on elliptic optical vortex array encoding/decoding

A multichannel high-dimensional data encoding/decoding scheme based on composite elliptic optical vortex (EOV) arrays is proposed. By exploiting the rotation angle of the EOV, a 4 × 4 composite EOV array is used for high-dimensional data encoding. The conjugate symmetric extension Fourier computer-generated holography algorithm with controllable reconstruction focus is used to assign different reconstruction focus to the data of the three channels (R, G, and B) of the color image. Then, the data of the three channels is transmitted simultaneously by a single hologram to further improve the transmission efficiency. At the receiver, the initial information sequence is decoded by directly identifying the captured intensity patterns with a deep learning-based convolutional neural network. In the experiment, a 128 × 128-pixel color image is successfully transmitted, which confirms the feasibility of our proposed encoding/decoding scheme. This method has great potential for future high-capacity optical communications.

Generation of vector elliptical perfect optical vortices with mixed modes in free space

Vector vortex beams are widely used because of their anisotropic vortex polarization state and spiral phase. Constructing mixed mode vector vortex beams in free space still requires complex designs and calculations. We propose a method for generating mixed mode vector Elliptical perfect optical vortex (EPOV) arrays in free space by mode extraction and optical pen. It is demonstrated that the long axis and short axis of EPOVs are not limited by the topological charge (TC). Flexible modulation of parameters in the array is achieved, including number, position, ellipticity, ring size, TC, and polarization mode. This approach is simple and effective, it will provide a powerful optical tool for optical tweezers, particle manipulation, and optical communication.