Jurkšaitis Povilas, Anulytė Justina, Spalinskaitė Evita, Bužavaitė-Vertelienė Ernesta, Žičkus Vytautas, Banevičius Dovydas, Kazlauskas Karolis, Balevičius Zigmas
Plasmonics and Nanophotonics Lab., Department of Laser Technologies, Center for Physical Sciences and Technology, Saulėtekio av. 3, LT-10257 Vilnius, Lithuania.
School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, UK.
Nanophotonics. 2025 Jun 24;14(14):2485-2493. doi: 10.1515/nanoph-2025-0129. eCollection 2025 Jul.
In this study, we investigate the contribution of resonant and non-resonant excitation conditions on the polariton decay dynamics of strongly coupled rhodamine 6G (R6G) and surface plasmon polariton (SPP). We showed proof of strong coupling between SPP and R6G exciton from the dispersion relations measured by total internal reflection ellipsometry (TIRE). From these it was determined that the coupling strength reaches ≈ 200 meV. Further fluorescence methods were employed to demonstrate the emission from the lower polariton branch (LP). The fluorescence lifetime and back focal plane imaging techniques were implemented to study radiative polariton decay, for resonant and non-resonant excitation conditions. Fluorescence decay measurements of plasmonic strong coupling regime showed considerably longer (ps) than expected lifetime values (fs). In our case the measured lifetimes cannot be explained without the influence of additional energy level in emission dynamics, such as incoherent transition from exciton reservoir to lower polaritonic branch. The fundamental understanding of coherent energy exchange dynamics has potential importance for development of quantum optical nanodevices, polaritonic lasers, polariton condensation.
在本研究中，我们探究了共振和非共振激发条件对强耦合罗丹明6G（R6G）与表面等离激元极化激元（SPP）的极化激元衰减动力学的影响。我们通过全内反射椭圆偏振光谱法（TIRE）测量的色散关系，证明了SPP与R6G激子之间存在强耦合。由此确定耦合强度达到约200毫电子伏特。我们采用进一步的荧光方法来证明来自下极化激元分支（LP）的发射。实施荧光寿命和后焦平面成像技术，以研究共振和非共振激发条件下的辐射极化激元衰减。等离子体强耦合 regime 的荧光衰减测量显示，其寿命比预期值（飞秒）长得多（皮秒）。在我们的案例中，如果不考虑发射动力学中额外能级的影响，如从激子库到下极化激元分支的非相干跃迁，就无法解释所测量的寿命。对相干能量交换动力学的基本理解对于量子光学纳米器件、极化激元激光器、极化激元凝聚的发展具有潜在的重要意义。
