The spin-orbit coupling interaction of the transition metal ion d orbitals and the conjugate π electrons can greatly enhance their reverse saturable absorption properties of the excited triplet state. 在此类化合物中,过渡金属离子的d轨道与共轭π电子的自旋-轨道耦合作用能大大增强了它们激发三重态的反饱和吸收性质。