Adjustable Elliptic Annular Optical Vortex Array

We present an elliptic annular optical vortex array (EOVA), whose annular eccentricity can be freely adjusted. The EOVA is generated by coherent superposition of two elliptic perfect optical vortices (EPOVs) with the same eccentricity. The vortex number and sign of the EOVA are determined by the difference of the topological charges (TCs) of these two EPOVs. Continuously increasing the initial phase difference between the EPOVs, each vortex of the EOVA can be rotated on the elliptic ring. Moreover, the birth process of a vortex is visualized by changing the TC of one of the EPOVs from an integer to the adjacent integer in steps of 0.1. This letter demonstrates a different spatial-structured optical vortex array, which is of significance in applications such as optical tweezers and micro-particle manipulation.