The plasmonic nanocavity is an excellent platform for the study of light matter interaction within a sub-diffraction volume under ambient conditions. We design a structure of plasmonic tweezers, which can trap molecular J-aggregates and also serve as a plasmonic cavity with which to investigate strong light matter interaction. The optical response of the cavity is calculated via finite-difference time-domain methods, and the optical force is evaluated based on the Maxwell stress tensor method. With the help of the coupled oscillator model and virtual exciton theory, we investigate the strong coupling progress at the lower level of excitons, finding that a Rabi splitting of 230 meV can be obtained in a single exciton system. We further analyze the relationship between optical force and model volume in the coupling system. The proposed method offers a way to locate molecular J-aggregates in plasmonic tweezers for investigating optical force performance and strong light matter interaction.

等离子体纳米腔是研究环境条件下亚衍射体积内光物质相互作用的绝佳平台。我们设计了一种等离子体镊子结构，它可以捕获分子 J 聚集体，也可以作为等离子体腔来研究强光物质相互作用。通过有限差分时域方法计算腔的光学响应，并基于麦克斯韦应力张量法评估光学力。借助耦合振子模型和虚拟激子理论，我们研究了低能级激子的强耦合过程，发现在单个激子系统中可以获得230 meV的Rabi分裂。我们进一步分析了耦合系统中光学力与模型体积之间的关系。