利用空间诱导色散概念,从理论上研究了等束腰宽度的类贝塞尔脉冲光束在自由空间中传输性质.在一阶近似的情况下,类贝塞尔脉冲光束的空间和时间部分可以做分离变量,空间部分在传输过程中保持类贝塞尔光束传输的特性,而时间波形部分的传输遵循空间诱导色散理论.利用数值模拟方法模拟了Bessel-Gauss脉冲光束和elegant Laguerre-Gauss脉冲光束的传输.结果证实,只要传输距离小于类贝塞尔光束的无衍射距离,空间诱导群速度色散理论能够很好地描述类贝塞尔脉冲光束脉冲形状的演化过程.
By using the concept of spatially induced group velocity dispersion,the propagation of Bessel-like pulsed beam which is constant beam waist in free space is studied. In the first order approximation,pulsed Bessel-like beam is variable separable,it can maintain its transverse profile during propagation,while the evolution of temporal shape can be described by spatially induced dispersion. By simulating the Bessel- Gauss pulsed beam and elegant Laguerre-Gauss pulsed beam, the simulation results confirm the existence of the spatially induced dispersion in the propagation of the Bessel-like pulsed beam. It is shown that the spatially induced dispersion can be observed when propagation distance is shorter than the diffraction-free length of Bessel-like beam.