Opt Lett. 2022 Dec 1;47(23):6213-6216. doi: 10.1364/OL.475271.
Multi-physics coupling, composed of an intense THz laser and electric field, serves as a new approach to realize the ultrahigh-level enhancement on third-harmonic generation (THG) of cubic quantum dots (CQDs). The exchange of quantum states caused by anticrossing of intersubbands is demonstrated by the Floquet method and finite difference method with the increasing laser-dressed parameter and electric field. The results show that the rearrangement of the quantum states excites the THG coefficient of CQDs four orders of magnitude higher than that achieved with a single physical field. The optimal polarization direction of incident light that maximizes the THG exhibits strong stability along the z axis at high laser-dressed parameter and electric field.
多物理场耦合，由强太赫兹激光和电场组成，是实现立方量子点（CQDs）三次谐波产生（THG）超高增强的新途径。通过 Floquet 方法和有限差分法，随着激光修饰参数和电场的增加，我们证明了子带间反交叉引起的量子态交换。结果表明，量子态的重新排列激发了 CQDs 的 THG 系数，比单个物理场实现的 THG 系数高出四个数量级。在高激光修饰参数和电场下，使 THG 最大化的最佳入射光偏振方向在 z 轴方向表现出很强的稳定性。
