模拟飞秒涡旋光在空气中成丝产生涡旋3次谐波的过程。研究初始基频波的扰动分布和峰值功率对双色涡旋光演化的影响。对于具有对称扰动分布的初始基频波，双色涡旋不受初始峰值功率影响，能够在成丝过程中保持环形强度分布。但是，在高峰值功率情况下，涡旋的螺旋相位分布受到多丝的影响，多丝引起的相位积累效应破坏了双色涡旋的螺旋相位分布。对于具有不对称扰动的初始基频波，当形成多细丝时，双色涡旋的空间环形分布和螺旋相位分布都会被破坏。
The third harmonic (TH) vortex generated by the filamentation of femtosecond vortex beam in air is simulated. The influences of perturbation distribution and peak power of the initial fundamental wave (FW) on the evolution of the two-color vortex are investigated. For the initial FW with symmetrical perturbation, the intensity annulus of the two-color vortex is not influenced by the initial peak power and can be kept in the filamentation regime. But the spiral phase distribution is influenced by multiple filamentation under the high peak power condition. In this case, the spiral phase distribution of the two-color vortex is destroyed due to the phase accumulation of the multiple filaments. For the initial FW with asymmetrical perturbation, both the spatial annulus and the spiral phase distribution of the two-color vortex are destroyed when multiple filaments are formed.
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