Multi-level exciton-polariton systems offer an attractive platform for studies of non-linear optical phenomena. However, studies of such consequential non-linear phenomena as polariton condensation and lasing in planar microcavities have so far been limited to two-level systems, where the condensation takes place in the lowest attainable state. Here, we report non-equilibrium Bose–Einstein condensation of exciton-polaritons and low threshold, dual-wavelength polariton lasing in vertically coupled, double planar microcavities. Moreover, we find that the presence of the non-resonantly driven condensate triggers interbranch exciton-polariton transfer in the form of energy-degenerate parametric scattering. Such an effect has so far been observed only under excitation that is strictly resonant in terms of the energy and incidence angle. We describe theoretically our time-integrated and time-resolved photoluminescence investigations by an open-dissipative Gross–Pitaevskii equation-based model. Our platform’s inherent tunability is promising for construction of planar lattices, enabling three-dimensional polariton hopping and realization of photonic devices, such as all-optical polariton-based logic gates.

中文翻译：

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非共振驱动耦合平面微腔中的偏振激光和能量简并参数散射

多级激子极化系统为非线性光学现象的研究提供了一个有吸引力的平台。然而，迄今为止，对平面微腔中极化子凝聚和激光等后续非线性现象的研究仅限于两能级系统，其中凝聚发生在最低可达到的状态。在这里，我们报告了激子极化子和低阈值、双波长极化激子在垂直耦合、双平面微腔中的非平衡玻色-爱因斯坦凝聚。此外，我们发现非共振驱动的凝聚物的存在以能量简并参数散射的形式触发了分支间激子 - 极化子转移。迄今为止，这种效应仅在能量和入射角严格共振的激发下观察到。我们通过基于开式耗散 Gross-Pitaevskii 方程的模型从理论上描述了我们的时间积分和时间分辨光致发光研究。我们平台的固有可调性有望用于构建平面晶格，实现三维极化子跳跃和光子器件的实现，例如基于全光极化子的逻辑门。