The Generation Of Stable Optical Vortex Clusters In Ginzburg-Landau Dissipative System

Optical vortex solitons(OVS)can be formed by vortex beam propagating in defocusing nonlinear material.The phase front of OVS is spiral,at the centre of spiral is a phase singularity that leads to a zero-field amplitude.The study of OVS have attracted a lot of interest,because OVS possess orbital angular momentum which can be used to manipulate microscopic particles.Standard soliton theory,nonlinear dynamics and its bifurcation theory and the ideas of systems far from equilibrium standard soliton theory are the main ideas of the concept of dissipative soliton.The formation of the stable dissipative solitons requires two kinds of balance,one is the balance between gain and loss and the other is the balance between linearity and nonlinearity.In addition,it also requires a continuous supply of matter and/or energy from the external of system.However,although there are many researches of vortex soliton and dissipative soliton,but the studies of stable optical vortex clusters embedding in dissipative media are still rare.In this thesis,we have investigated the generation of stable optical vortex clusters nested in a two-dimensional vortex Gaussian beam.We can see that,in a dissipative system described by the cubic-quintic(CQ)complex Ginzburg-Landau(CGL)equation with an inhomogeneous effective diffusion term which is asymmetric in two transverse directions and periodically modulated in the longitudinal direction,input Gaussian beam with different values of the topological charge can evolve into stable optical vortex clusters.And the number of optical vortex solitons which form the robust optical vortex clusters is equal to the value of topological charge of the input Gaussian beam.In addition,we also find the relations of amplitudes and period of the inhomogeneous effective diffusion and coefficients of the cubic gain and diffusion,which affect the regions of the existence and stability of the vortex cluster.Finally,the result of this study put forward a way to generate stable vortex clusters nesting in a two-dimensional optical beam,and it will have a great potential for applications in the area of structured light.