Generalized high-order twisted partially coherent beams and their propagation characteristics

Twist phase is a nontrivial statistical phase that only exists in partially coherent fields, which makes the beam carry orbital angular momentum (OAM). In this paper, we introduce a new kind of partially coherent beams carrying high-order twist phase, named generalized high-order twister partially coherent beams (GHTPCBs). The propagation dynamics such a the spectral density and OAM flux density propagating in free space an investigated numerically with the help of mode superposition and fast Fourier transform (FFT) algorithm. Our results show that the GHTPCBs are capable of self-focusing, and the beam spot during propagatior exhibits teardrop-like or the diamond-like shape in some certain cases Moreover, the influences of the twist order and the twist factor on the OAM flux density during propagation are also illustrated in detail. Finally we experimentally synthesize the GHTPCBs with controllable twist phase by means of pseudo-mode superposition and measure their spectral density during propagation. The experimental results agree well with the theoretical predictions. Our studies may find applications in nonlinear optics and particle trapping.

Automated summary

In this paper, a new type of partially coherent beams called generalized high-order twister partially coherent beams (GHTPCBs) is introduced, which can carry high-order twist phase and orbital angular momentum (OAM). The propagation dynamics of GHTPCBs in free space, including spectral density and OAM flux density, are numerically investigated using mode superposition and fast Fourier transform (FFT) algorithm. The results show that GHTPCBs can self-focus and exhibit teardrop-like or diamond-like beam spot shapes during propagation under certain conditions. The effects of twist order and twist factor on OAM flux density during propagation are also illustrated in detail. Additionally, GHTPCBs with controllable twist phase are experimentally synthesized using pseudo-mode superposition, and their spectral density during propagation is measured. The experimental results are in good agreement with the theoretical predictions. The findings of this study may have applications in nonlinear optics and particle trapping.