High uniformity Bessel beams with angle-controllable steering

Bessel beams with controllable output angles and uniform intensity distribution along the propagation direction have critical applications in many fields. This paper introduces a novel method to generate high uniformity, high signal-to-noise ratio, and angle-controllable Bessel beams by combining a Fresnel zone plate (FZP) with an axicon. An apodizing phase axicon with an ideally fitted profile is used, with a Gaussian beam as the light source. The fitting profile is then optimized through a genetic algorithm (GA) and an unconstrained nonlinear optimization algorithm (UNMA). The combination of the optimized apodizing phase axicon and FZP achieves the uniform distribution of axial intensity and the control of Bessel beam angle by changing the center of FZP. The results demonstrate the effectiveness of this method, showing that it can achieve arbitrary angle control within the range of 4.0742°, with a resolution of 0.0008° and a uniformity of 94.66%. Furthermore, this method can be extended to multiple Bessel beams, enabling the angle control of various Bessel beams.