采用ππ偏振激光,通过两步激发和光电离方法,在0～1514 V/cm电场范围内,测定了Yb原子n=18附近m=0的斯塔克光谱.首次把包含斯塔克效应的能量矩阵对角化方法推广到Yb原子,所获得的理论斯塔克图与实验结果基本符合.观察到低场中斯塔克簇随电场增加呈现线性结构以及1P1态与斯塔克簇在抗交叉过程中振子强度发生转移的现象.讨论了能级结构与量子亏损的关系.

The Stark spectra of Yb atom with m= 0 in the vicinity of n-18 wereobtained by using two-step excitation of π π polarized lasers in the applied electric field from o V/cm to 1514 V/cm. The method based on diagonalization of the energy matrix with the Stark effect was applied to Yb atom. The theoretical Stark map agrees with experimental Stark map. It is observed that Stark manifold exhibits linear structure with theincrease of the electric field in the low-field region. A large oscillator-strength transfer between 1P1 state and nearby Stark manifold occurs in the course of anticrossing. The dependence of level-structure on quantum effects is discussed.