Versatile non-diffracting beams generator based on free lens modulation

Non-diffracting beams, notable for their self-healing properties, high-localized intensity profiles over extended propagation distances, and resistance to diffraction, present significant utility across various fields. In this letter, we present a versatile and highly efficient non-diffracting beams (NDBs) generator predicated on the Fourier transformation of the focal plane fields produced through the free lens modulation. We demonstrate the experimental generation of high-quality Bessel beams, polymorphic generalized NDBs, tilted NDBs, asymmetric NDBs, and specially structured beams formed by the superposition of co-propagating beams. The versatile generalized NDBs generator is anticipated to find applications in laser processing, optical manipulation, and other fields.