3D adjustable autofocusing multi-foci of chirped Airy beam arrays

To overcome the limitations of existing multi-focus modulation techniques in terms of 3D spatial flexibility, we propose a zonal phase modulation technique based on classified chirp factors, successfully achieving precise multi-focus manipulation of chirped Airy beam arrays in 3D space. Theoretical and experimental results demonstrate that the 3D autofocusing multi-focus performance of chirped Airy beam arrays (CPABAs)-including the number of foci, the transverse spacing between foci, the relative intensity of foci, and the focal length-can be flexibly controlled by adjusting the sub-beam classification number G, the first-order chirp factor c1G, and the second-order chirp factor c2G. The presented work provides a new, to our knowledge, approach for 3D multi-focus manipulation of autofocusing beam arrays. These controllable 3D autofocusing multiple focal spots have broad applications in multi-particle parallel trapping, 3D data storage, and laser processing.