Optical Fields: Flower-Shaped Optical Vortex Array (Ann. Phys. 4/2021)

The cover illustrates a structured optical field, dubbed a flower-shaped optical vortex array by Xinzhong Li and co-workers in article number 2000575. The inner layer uses a clock to represent the phase change, the hour hand represents the phase of the even IG beam, and the minute hand represents the phase of the odd IG beam. The outer layer is a specific example of an optical field, which keeps the phase of the odd IG beam unchanged, and changes the phase of the even IG beam, As the phase difference between the even mode IG beam and the odd mode IG beam increases, the optical field rotates gradually.