self-focusing beam造句

• To deal with the case of 2 dimension spatial self - focusing , it predicts the catastrophic collapse of a self - focusing beam in a kerr medium . this un - physical collapse is due to the invalidity of the paraxial wave equation in the neighborhood of a self - focus
  在该理论应用于空间二维的自聚焦时，出现了光束将无限聚焦的结果，这在物理上是不可想像的，原因是在自聚焦点附近傍轴方程已经失效了。