Effects of the septic nonlinearity and the initial value of the radius of orbital angular momentum beams on data transmission in optical fibers using the cubic-quintic-septic complex Ginzburg-Landau equation in presence of higher-order dispersions

In a three-dimensional (3D) dissipative medium described by the higher-order (3+1)-dimensional cubic-quintic-septic complex Ginzburg-Landau [(3+1)D CQS-CGL] equation with the viscous (spectral-filtering) term, self steepening, Raman effect, dispersion terms up to six, diffraction and cubic-quintic-septic nonlinearities, we demonstrate that necklace ring beams with initial spherical shape carrying integer and even fractional angular momentum and whose intensities are azimuthally periodically modulated, can evolve into caterpillar, hexagonal, rectangular, scorpion, diamond and pillow dissipative optical bullets. The outcome of the evolution is controlled by the radius and the value of the septic nonlinearity in the initial necklace ring. We reveal numerically that spatiotemporal necklace-ring solitons carrying integer, and even fractional angular momentum can be self-trapped over a huge propagation distance even in the presence of random perturbations.