近场激发下的量子点共振能量转移研究

Resonant energy transfer between quantum dots under near-field excitation

研究了近场光激发下的两量子点之间的共振能量转移情况,采用场极化率张量和量子光学中的光学布洛赫方程相结合的方法得到了两个量子点相互作用的密度矩阵元以及各自的发光强度,分析了周围环境(以探针体为例)对共振能量转移的影响,提供了一种在微纳尺度范围内研究量子点之间能量耦合和转移的理论分析方法。另外,还考虑了不同偏振态入射光对量子点发光强度的影响,简要分析表明当入射光偏振态和量子点之间连线方向相同时,量子点发光强度增强,反之减弱。

We develop a theoretical framework for investigation of resonant energy transfer in complex environments under optical near-fields excitation. By combining the fieldsusceptibility formalism with the optical Bloch equations method, we derive the density ma. trix elements and their emitting signal intensity for the computation of the energy transfer between two quantum dots excited by optical near fields and placed in a complex geometry. It provides a theoretical method to investigate the resonant energy transfer between quantum dots at the microscale. Moreover, we consider the quantum dots luminescence intensity for different polarization incident light, the results show that the luminescence intensity can be strongly enhanced when the illumination polarization state is along the direction of the two quantum dots.