Controlling low power light beam self-confinement with ultrafast response time opens up opportunities for the development of signal processing in microdevices. The combination of a highly nonlinear medium with the tight confinement of plasmonic waves offers a viable but challenging configuration to reach this goal. In the present work, a beam propagating in a plasmonic structure that undergoes a strongly enhanced self-focusing effect is reported for the first time. The structure consists of a chalcogenide-based four-layer planar geometry engineered to limit plasmon propagation losses while exhibiting efficient Kerr self-focusing at moderate power. As expected from theory, only TM-polarized waves exhibit such a behavior. Different experimental arrangements are tested at telecom wavelengths and compared with simulations obtained from a dedicated model. The observed efficient beam reshaping takes place over a distance as low as 100 μm, which unlocks new perspectives for the development of integrated photonic devices.

中文翻译：

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非线性自限制等离子束：实验证明

以超快的响应时间控制低功率光束的自约束，为微设备中信号处理的发展打开了机遇。高度非线性的介质与等离子体波的严格限制相结合，为实现该目标提供了可行但具有挑战性的配置。在目前的工作中，首次报道了在等离子体结构中传播的光束受到强烈增强的自聚焦作用。该结构由基于硫族化物的四层平面几何结构组成，旨在限制等离子体激元的传播损耗，同时在中等功率下表现出有效的Kerr自聚焦。从理论上可以预期，只有TM极化波才会表现出这种行为。在电信波长下测试了不同的实验方案，并与从专用模型获得的仿真结果进行了比较。观察到的有效光束整形发生在低至100μm的距离上，这为集成光子器件的开发开辟了新的前景。