Tunable Bessel and annular beams generated by a unimorph deformable mirror

Abstract

High-quality Bessel beams with adjustable cone angles are realized using a unimorph deformable mirror (DM) with 61 actuators. The DM not only generates an adjustable diverging or converging conical mirror surface in high precision, but also corrects the optical aberrations in the optical system. Furthermore, the annular beams are generated via the Fourier transform of the generated Bessel beams. The core size of the Bessel beam and the radius of the annular beam are proved to be flexibly controlled by the DM without changing the optical elements and realigning the optical path. Since the unimorph DM has a very high damage threshold, the proposed method paves the way for potential applications involving high-power lasers.