复宗量Laguerre-Gauss光束在强非局域非线性介质中的传输

Propagation of complex argument Laguerre-Gaussian beams in strongly nonlocal nonlinear media

研究得到了偏离束腰入射的复宗量Laguerre-Gauss光束在强非局域非线性介质中传输的解析表达式,并且得到了其二阶矩束宽的解析解.通过例子研究了偏离束腰入射的复宗量Laguerre-Gauss光束在强非局域非线性介质中传输性质.结果表明:非(0,m)模的复宗量Laguerre-Gauss光束的光束形状随着传输而发生改变,并以Δz=πzc为周期做周期性演化.而(0,m)模复宗量Laguerre-Gauss光束在演化过程中则形状保持不变,仅改变光束宽度;不论功率多大,在偏离束腰入射条件下总是表现为呼吸子;只有当其为束腰入射,并且入射功率等于临界功率时才能形成孤子.

In this paper,we obtain the analytical solution of the off-waist inputted complex argument Laguerre-Gaussian beams and their mean squared beam width in nonlocal nonlinear media.The propagation of the complex argument Laguerre-Gaussian beams in the nonlocal nonlinear media is investigated in detail.The examples show that the pattern shape of a（n,m） mode complex argument Laguerre-Gaussian beam varies periodically with the period Δz = πzc in strongly nonlocal nonlinear media if n≠0.But if n = 0,its pattern shape remains unvaried and the beam width varies periodically during propagation.Under the off-waist incident condition,the propagation of the（0,m） mode complex argument Laguerre-Gaussian beam behaves as a breather during propagation,no matter what the power of the incident beam is.Only when the beam is input at the waist and the input power equals the critical power would the breather be reduced to a soliton.