Cakmak Atilla Ozgur, Colak Evrim, Serebryannikov Andriy E, Ozbay Ekmel
Nanotechnology Research Center, Department of Physics, Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara, Turkey.
Opt Express. 2010 Oct 11;18(21):22283-98. doi: 10.1364/OE.18.022283.
Unidirectional transmission is studied theoretically and experimentally for the gratings with one-side corrugations (non-symmetric gratings), which are based on two-dimensional photonic crystals composed of alumina rods. The unidirectional transmission appears at a fixed angle of incidence as a combined effect of the peculiar dispersion features of the photonic crystal and the properly designed corrugations. It is shown that the basic unidirectional transmission characteristics, which are observed at a plane-wave illumination, are preserved at Gaussian-beam and horn antenna illuminations. The main attention is paid to the single-beam unidirectional regime, which is associated with the strong directional selectivity arising due to the first negative diffraction order. An additional degree of freedom for controlling the transmission of the electromagnetic waves is obtained by making use of the asymmetric corrugations at the photonic crystal interface.
对基于由氧化铝棒组成的二维光子晶体的单侧波纹光栅（非对称光栅）的单向传输进行了理论和实验研究。单向传输在固定入射角出现，这是光子晶体特殊色散特性和适当设计的波纹共同作用的结果。结果表明，在平面波照明下观察到的基本单向传输特性在高斯光束和喇叭天线照明下得以保留。主要关注的是与由于第一负衍射级产生的强方向选择性相关的单光束单向模式。通过利用光子晶体界面处的非对称波纹，获得了控制电磁波传输的额外自由度。
