when the spatial parameter a is small, the non-paraxial effect does n't affect the temporal profile of the beam . however, when a becomes relatively larger, it influences the temporal profile greatly 当空间参数较小时超短脉冲贝塞尔光束的时间波形不受非近轴效应影响;然而当空间参数较大时,非近轴效应影响超短脉冲贝塞尔光束的时间波形。