Nonparaxial propagation and the radiation forces of the chirped circular Airy derivative beams.

In this paper, we investigate the nonparaxial propagation dynamics of the chirped circular Airy derivative beams (CCADBs) based on vector angular spectrum method. In the case of nonparaxial propagation, the CCADBs still maintains excellent autofocusing performances. Derivative order and chirp factor are two important physical quantities of the CCADBs to regulate the nonparaxial propagation characteristics, such as focal length, focal depth and K-value. In the nonparaxial propagation model, the radiation force on a Rayleigh microsphere induced the CCADBs are also analyzed and discussed in detail. The results demonstrate that not all derivative order CCADBs can achieve stable microsphere trapping effect. The derivative order and chirp factor of the beam can be used to coarse and fine tune the capture effect of Rayleigh microsphere, respectively. This work will contribute to the more precise and flexible use of circular Airy derivative beams in optical manipulation, biomedical treatment and so on.