BK21 Plus Transformative Program for Creative Mechanical & Aerospace Engineers, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
School of Mechanical and Aerospace Engineering, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, South Korea.
Sci Rep. 2018 Jan 8;8(1):69. doi: 10.1038/s41598-017-18408-5.
We establish the theory for perfect transmodal Fabry-Perot interferometers that can convert longitudinal modes solely to transverse modes and vice versa, reaching up to 100% efficiency. Two exact conditions are derived for plane mechanical waves: simultaneous constructive interferences of each of two coupled orthogonal modes, and intermodal interference at the entrance and exit sides of the interferometer with specific skew polarizations. Because the multimodal interferences and specific skew motions require unique anisotropic interferometers, they are realized by metamaterials. The observed peak patterns by the transmodal interferometers are similar to those found in the single-mode Fabry-Perot resonance, but multimodality complicates the involved mechanics. We provide their design principle and experimented with a fabricated interferometer. This theory expands the classical Fabry-Perot resonance to the realm of mode-coupled waves, having profound impact on general wave manipulation. The transmodal interferometer could sever as a device to transfer wave energy freely between dissimilar modes.
我们建立了完美的跨模态法布里-珀罗干涉仪的理论，该干涉仪可以将纵向模式完全转换为横向模式，反之亦然，效率高达 100%。我们推导出了平面机械波的两个精确条件：两个耦合正交模式的每一个的同时建设性干扰，以及干涉仪进出口处的模式间干扰，具有特定的斜偏振。由于多模干涉和特定的斜向运动需要独特的各向异性干涉仪，因此它们由超材料实现。跨模态干涉仪观察到的峰值模式与单模法布里-珀罗共振中发现的模式相似，但多模性使所涉及的力学变得复杂。我们提供了它们的设计原理，并对制造的干涉仪进行了实验。该理论将经典的法布里-珀罗共振扩展到模式耦合波的领域，对一般波的操纵具有深远的影响。跨模态干涉仪可以作为在不同模式之间自由传输波能量的设备。
