Optical properties of spherical microcavities doped with quantum dots

在掺杂半导体量子点的球形微腔中，研究了三维受限光子态与三维受限电子态的相互作用。为此，将通过化学方法制备半径在2至20微米之间的聚合物球体，并在其中掺杂不同材料和浓度的量子点(QD)，作为腔内的有源光学发射体。通过空间和时间分辨的微光致发光实验，研究了单个QD掺杂球体和球团簇的发射与球的大小和量子点的大小、温度、激发强度和能量的关系。该项目的目标是(A)开发新的制备方法，以实现高质量的腔质量Q和可控地调节微腔和量子点的大小，(B)研究由几个球组成的阵列的光学性质，(C)测试掺杂量子点的微球在可见光谱范围内作为低阈值激光器，以及(D)实现离散量子点态与腔模式之间的强耦合限制。

The interaction of three-dimensionally confined photonic states with three-dimensionally confined electronic states will be studied in spherical microcavities doped with semiconductor quantum dots. To do this, polymeric spheres of radii between 2 and 20 µm will be chemically prepared and doped with quantum dots (QDs) of different materials and concentrations acting as the active optical emitter inside the cavity. By use of spatially and temporally resolved micro-photoluminescence experiments, the emission of single QD-doped spheres and of ensembles of spheres will be investigated in dependence on size of the spheres and size of the quantum dots, on temperature, excitation intensity and energy. The project is aimed at (a) the development of new preparation methods to achieve a high cavity quality Q and a controlled adjustment of sizes of both the microcavities and the quantum dots, (b) the study of the optical properties of arrays made from several spheres, (c) the test of microspheres doped with quantum dots as low-threshold laser in the visible spectral range, and (d) to achieve the limit of strong coupling between the discrete quantum dot states and the cavity modes.