Zhang Zhifang, Yan Jia, Dong Zuoru, Zhang Ningning, Chen Peizong, Peng Kun, Zhu Yanyan, Zhong Zhenyang, Jiang Zuimin
State Key Laboratory of Surface Physics, Department of Physics, Fudan University, Shanghai 200438, China.
Shanghai Microwave Technology Research Institute, Shanghai 200063, China.
Nanomaterials (Basel). 2023 Sep 13;13(18):2553. doi: 10.3390/nano13182553.
The coupling between the quantum dots (QDs) and silicon-based microdisk resonator facilitates enhancing the light-matter interaction for the novel silicon-based light source. However, the typical circular microdisks embedded with Ge QDs still have several issues, such as wide spectral bandwidth, difficult mode selection, and low waveguide coupling efficiency. Here, by a promising structural modification based on the mature nanosphere lithography (NSL), we fabricate a large area hexagonal microdisk array embedded with Ge QDs in order to enhance the near-infrared light emissions by a desired whispering gallery modes (WGMs). By comparing circular microdisks with comparable sizes, we found the unique photoluminescence enhancement effect of hexagonal microdisks for certain modes. We have confirmed the WGMs which are supported by the microdisks and the well-correlated polarized modes for each resonant peak observed in experiments through the Finite Difference Time Domain (FDTD) simulation. Furthermore, the unique enhancement of the TE mode in the hexagonal microdisk is comparatively analyzed through the simulation of optical field distribution in the cavity. The larger enhanced region of the optical field contains more effectively coupled QDs, which significantly enhances the PL intensity of Ge QDs. Our findings offer a promising strategy toward a distinctive optical cavity that enables promising mode manipulation and enhancement effects for large-scale, cost-effective photonic devices.
量子点（QDs）与硅基微盘谐振器之间的耦合有助于增强新型硅基光源的光与物质相互作用。然而，典型的嵌入锗量子点的圆形微盘仍存在一些问题，如光谱带宽宽、模式选择困难以及波导耦合效率低等。在此，通过基于成熟的纳米球光刻（NSL）进行的一种有前景的结构改性，我们制备了一种嵌入锗量子点的大面积六边形微盘阵列，以便通过所需的回音壁模式（WGMs）增强近红外光发射。通过将圆形微盘与尺寸相当的微盘进行比较，我们发现六边形微盘对某些模式具有独特的光致发光增强效果。我们通过有限时域差分（FDTD）模拟，证实了微盘所支持的WGMs以及在实验中观察到的每个共振峰的良好相关偏振模式。此外，通过对腔内光场分布的模拟，对六边形微盘中TE模式的独特增强进行了比较分析。光场的较大增强区域包含更多有效耦合的量子点，这显著提高了锗量子点的光致发光强度。我们的研究结果为实现一种独特的光学腔提供了一种有前景的策略，该光学腔能够为大规模、具有成本效益的光子器件实现有前景的模式操控和增强效果。
