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 c 1 G , and the second-order chirp factor c 2 G . 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.