Kerr效应对超高斯光束聚焦特性的影响

利用菲涅耳-基尔霍夫衍射积分公式,对一维超高斯光束通过克尔介质的聚焦特性进行了研究.在相位延迟为-2 rad~2 rad的范围内进行了计算.模拟结果表明,正Kerr效应将提高聚焦强度、增大相对焦移量和降低几何焦平面的峰值光强;而负Kerr效应,则会降低聚焦强度、增大相对焦移量和降低几何焦平面的峰值光强.可以将这两种的情况联合起来进行讨论,并可以通过增大光束的菲涅耳数来降低Kerr效应对其聚焦特性的影响.

The influence of the Kerr effect on the focusing property of the super-Gaussian beam

Based on the Fresnel-Kirchhoff diffraction theory,the focusing property of the one-dimension super-Gaussian beam transmitted through the thin Kerr medium is studied.The simulation for the phase-delay ranging-2rad~2rad is made,and the results show that,for the medium with positive nonlinear refraction index,the Kerr effect of the beam improves the focused intensity,broadens the relative focal shift and reduces the peak intensity on the geometry focal plane;but for negative index medium,it will reduce the focused intensity,however,the other focusing properties remain the same as the positive one.Both conditions can be discussed together,and the influence of the Kerr effect on the focusing property can be reduced by enlarging the beam Fresnel number.