Tailoring the chirality of an optical vortex is crucial for advancing helical chiroptical spectroscopy techniques in various scenarios and attracts great attention. In contrast to the single vortex, the optical vortex pair exhibits richer, fantastic chirality properties due to its additional adjustment parameters. Here, a comprehensive investigation of the chirality for linearly polarized optical vortex pairs based on the vector angular spectrum decomposition method is conducted. The numerical results show that the magnitudes and distributions of local chirality density, helical dichroism, and enantioselective force of the optical vortex pair can be flexibly customized by the position as well as sign combination of vortices, and can vary during free space propagation. The underlying physical mechanism behind these phenomena is ascribed to the interplay of two vortices. Our work can deepen the understanding of the chirality for multiple vortices and open-up the prospect for relevant applications in chiral recognition and manipulation.

Non-diffracting beams play crucial roles in the field of free-space optical communication due to their robust resistance to distortion in atmospheric turbulence. As a non-diffracting beam characterized by multiple parameters, the Tricomi beam exhibits great versatility and adjustability, attracting considerable interest recently. In this paper, we study the propagation properties of Tricomi beam in atmospheric turbulence based on the theory of random phase screen. It is found that the performance of Tricomi beam in atmospheric turbulence shows strong dependence on its asymmetric constants, topological charge, and half-cone angle. Meanwhile, the Tricomi beam manifests superior resistance to distortion and spatial mode stability in contrast to the conventional non-diffracting Bessel beam. Our work provides a valuable theoretical foundation for the design and performance optimization of next-generation free-space optical communication systems, potentially enabling enhanced data transmission fidelity over long atmospheric paths.