Publications by authors named "Shandong Tong"

In this paper, the circular Bessel Gaussian beams (CBGBs) carrying power-cotangent-phase vortices are firstly introduced, whose propagation dynamics are explored theoretically and experimentally. The number of spiral lobes, rotation direction, rotation angle, and shape of the new type of beam can be flexibly modulated by controlling multiple parameters of power-cotangent-phase vortices. Accordingly, the effect of multiple beam parameters on abruptly autofocusing ability is quantified and compared by using the K-value curve that is described by ratio Im/I, where Im and I correspond to the maximum intensities at different propagation distance and the initial plane, respectively.

View Article and Find Full Text PDF

In this paper, we firstly propose a method to measure the topological charges (TCs) of a circular Bessel Gaussian beam with multiple vortex singularities (CBGBMVS) by utilizing cross phase. Based on theory and experiment, the cross phase is utilized to realize the TCs measurement of the CBGBMVS in free space with different situations, such as different singularity number, TCs and singularity location. Especially, the TCs measurement method is also investigated and verified in atmosphere turbulence.

View Article and Find Full Text PDF

In this paper, the circular Airy derivative beams carrying rotationally-symmetric power-exponent-phase vortices are proposed for the first time, whose evolutionary properties are explored by theoretical analysis as well as experimental verification. The intensity and phase distributions of this kind of beam can be flexibly modulated by controlling its parameters such as derivative order, topological charge, and power order. Intriguingly, the evolution of such beams with different fractional topological charges is also investigated in detail by means of phase singularities distribution.

View Article and Find Full Text PDF