We find that the emission from laterally coupled quantum dots is strongly polarized along the coupled direction [1\(\bar 1\)0], and its polarization anisotropy can be shaped by changing the orientation of the polarized excitation. When the nonresonant excitation is linearly polarized perpendicular to the coupled direction [110], excitons (X₁ and X₂) and local biexcitons (X₁X₁ and X₂X₂) from the two separate quantum dots (QD₁ and QD₂) show emission anisotropy with a small degree of polarization (10%). On the other hand, when the excitation polarization is parallel to the coupled direction [1\(\bar 1\)0], the polarization anisotropy of excitons, local biexcitons, and coupled biexcitons (X₁X₂) is enhanced with a degree of polarization of 74%. We also observed a consistent anisotropy in the time-resolved photoluminescence. The decay rate of the polarized photoluminescence intensity along the coupled direction is relatively high, but the anisotropic decay rate can be modified by changing the orientation of the polarized excitation. An energy difference is also observed between the polarized emission spectra parallel and perpendicular to the coupled direction, and it increases by up to three times by changing the excitation polarization orientation from [110] to [1\(\bar 1\)0]. These results suggest that the dipole–dipole interaction across the two separate quantum dots is mediated and that the anisotropic wavefunctions of the excitons and biexcitons are shaped by the excitation polarization.

我们发现横向耦合量子点的发射沿耦合方向[1 \(\bar 1\) 0]强烈偏振，并且其偏振各向异性可以通过改变偏振激发的方向来形成。当非共振激发垂直于耦合方向[110]线性极化时，来自两个单独的量子点（QD ₁和 QD ₂ ）的激子（X ₁和 X ₂ ）和局部双激子（X ₁ X ₁和 X ₂ X ₂ ） ）显示出具有小偏振度（10%）的发射各向异性。另一方面，当激发偏振平行于耦合方向[1 \(\bar 1\) 0]时，激子、局部双激子和耦合双激子(X ₁ X ₂ )的偏振各向异性增强一定程度极化率74%。我们还观察到时间分辨光致发光具有一致的各向异性。偏振光致发光强度沿耦合方向的衰减率相对较高，但各向异性衰减率可以通过改变偏振激发的方向来改变。在平行和垂直于耦合方向的偏振发射光谱之间还观察到能量差异，并且通过将激发偏振方向从 [110] 更改为 [1 \(\bar 1\) 0]，能量差异最多增加三倍。这些结果表明，两个单独的量子点之间的偶极-偶极相互作用是介导的，并且激子和双激子的各向异性波函数是由激发极化形成的。