Sambles J Roy, Kelly Robert, Yang Fuzi
Thin Film Photonics Group, School of Physics, University of Exeter, Exeter EX4 4QL, UK.
Philos Trans A Math Phys Eng Sci. 2006 Oct 15;364(1847):2733-46. doi: 10.1098/rsta.2006.1850.
While the use of liquid crystals (LCs) over the visible region is ubiquitous in flat-screen displays, there has been little by the way of applications at other wavelengths. Specifically, notwithstanding the continuing permittivity anisotropy to be found at longer wavelengths, there has been virtually no development in the microwave domain. This is largely due to the fact that scaling up the micrometer-thick LC layers used for visible radiation to millimetre dimensions is seen as impractical. In this study, it is shown how, using thin slits in metal structures, a completely new generation of LC devices for use at microwaves may be realized. Such structures include slatted metal Fabry-Perot resonators, beam-steering devices, thin flexible voltage tunable filters and even cascade structures with strongly enhanced and reshaped microwave fields.
虽然液晶在可见光区域用于平板显示器已无处不在，但在其他波长的应用却很少。具体而言，尽管在较长波长下仍能发现介电常数各向异性，但在微波领域几乎没有什么进展。这主要是因为将用于可见光辐射的微米厚液晶层扩大到毫米尺寸被认为是不切实际的。在本研究中，展示了如何利用金属结构中的细缝实现全新一代用于微波的液晶器件。此类结构包括板条金属法布里-珀罗谐振器、波束控制装置、薄型柔性电压可调滤波器，甚至是具有强烈增强和重塑微波场的级联结构。
