Analysis of Metallic Space-Time Gratings Using Lorentz Transformations

被引:8
|
作者
Alex-Amor, Antonio [1 ]
Molero, Carlos [2 ]
Silveirinha, Mario G. [3 ,4 ]
机构
[1] CEU Univ, Univ San Pablo CEU, Dept Informat Technol, Campus Monteprincipe, Boadilla Del Monte 28668, Madrid, Spain
[2] Univ Granada, Dept Signal Theory Telemat & Commun, Granada 18071, Spain
[3] Univ Lisbon, Inst Super Tecn, P-1049001 Lisbon, Portugal
[4] Univ Lisbon, Inst Telecomunicacoes, P-1049001 Lisbon, Portugal
关键词
EQUIVALENT-CIRCUIT APPROACH; DIFFRACTION; REFLECTION; SPECTROSCOPY; MODULATION; SHIFT;
D O I
10.1103/PhysRevApplied.20.014063
中图分类号
O59 [应用物理学];
学科分类号
摘要
This paper presents an analytical framework for the study of scattering and diffraction phenomena in space-time-modulated metallic gratings. Using a Lorentz transformation, it is shown that a particular class of space-time-modulated gratings behave effectively as moving media. We take advantage of this property to derive a closed analytical solution for the wave scattering problem. In particular, using our formalism it is possible to avoid space-time Floquet-Bloch expansions, as the solution of the problem in the original laboratory frame (grating parameters are periodic in space and time) is directly linked to a comoving frame where the metallic grating is time invariant (grating parameters are periodic only in space). In this way, we identify a fundamental connection between moving metallic gratings and space-time-modulated metamaterials, and exploit this link to study the nonreciprocal response of the structure. Some limitations and difficulties of the alternative nonrelativistic Galilean approach are discussed and the benefits of the Lorentz approach are highlighted. Finally, some analytical results are presented in order to validate the formalism. The results include scenarios involving TM (p) and TE (s) normal and oblique incidence, even beyond the onset of the diffraction regime. Furthermore, we show how the synthetic Fresnel drag can tailor the Goos-Hanchen effect and create a specular point shifted towards the direction of the synthetic motion, independent of the sign of the incidence angle.
引用
收藏
页数:15
相关论文
共 50 条