Design of pupil filter for scalable generation of uniform foci array

Abstract

In this paper, the original focus under tightly focusing radially polarized Bessel–Gaussian beam is split into a foci array with a specially designed pupil filter modulation. With this method, foci in the array are precisely controlled at accurate positions, exhibiting almost identical intensities and weak side lobes. Furthermore, a compound modulation through superposition of several filters is theoretically investigated, and a method for scalable generation of uniform foci array on the basis of their subarrays is proposed, which greatly reduced the design complexity of the large-scale foci array. With this method, various kinds of uniform foci arrays with large amount of foci and attractive distributions are well modulated, which may find potential applications in multifocal multiphoton microscopy and parallel laser fabrication.