Dependence of autofocusing ability of a ring Airyprime beams array on the number of beamlets.

A ring Airyprime beams (RAPB) array, which consists of N evenly displaced Airyprime beamlets in the initial plane, is first introduced, to the best of our knowledge, in this Letter. Here, we focus on the effect of the number of beamlets N on the autofocusing ability of the RAPB array. With the given beam parameters, an optimal number of beamlets, which is the minimum number of beamlets to realize the saturated autofocusing ability, is selected. The focal spot size of the RAPB array remains unchanged before the number of beamlets reaches the optimal number of beamlets. More importantly, the saturated autofocusing ability of the RAPB array is stronger than that of the corresponding circular Airyprime beam. The physical mechanism of the saturated autofocusing ability of the RAPB array is interpreted by simulating the Fresnel zone plate lens. The influence of the number of beamlets on the autofocusing ability of the ring Airy beams (RAB) array under the same beam parameters with the RAPB array is also presented for comparison. Our findings are beneficial for the design and application of the ring beams array.