Generation, Detection and Light-Matter Interactions of Focused Doughnut Pulses

聚焦的甜甜圈是麦克斯韦方程的解，它只存在于以光速在自由空间传播的电磁能量的短爆发形式中。它们与横波的区别在于电磁场的环面结构和沿传播方向的强场分量。其中，它们非常重要，因为它们与过去在南安普顿大学光电子研究中心广泛研究的环面激励相似。由于它们在物质中产生的特殊激发，它们的产生可能为新的光谱学方法开辟了道路。在这个研究项目中，我们从理论上和实验上研究了它们的产生、探测和与物质的相互作用。在对其特性进行理论研究后，我们试图了解它们的光学特性，以便在实验室中进行精确操作。它们的产生似乎可以通过与适当设计的超表面的宽带脉冲相互作用来实现。一些脉冲表征技术将被应用于测试和？重新调整他们这一代人。最后，设计了光物质相互作用的环面模激发实验和动态模拟实验。

Focused doughnuts are solutions to Maxwell's equations that exist only in the form of short burst of electromagnetic energy propagating in free-space at the speed of light. They are distinguished from transverse waves by a toroidal configuration of electromagnetic fields and strong field components along the propagation direction. Among others, they are of great importance because of the similarities with the toroidal excitations, that were studied extensively at the Optoelectronics Research Centre of the University of Southampton in the past. Their generation could open the way for new spectroscopic methods, due to the peculiar excitations that they create in matter. In this research project we study, theoretically and experimentally, their generation, detection and interaction with matter. After a theoretical examination of their characteristics, we seek to understand their optical properties for precise manipulation in the laboratory. Their generation seems to be possible via a broadband pulse interaction with a properly engineered metasurface. A number of pulse characterization techniques will be applied in order to test and ?re-tune their generation. Finally, light matter interaction experiments for the excitation of toroidal modes and dynamic anapoles will be designed.