State Key Laboratory of Advanced Optical Communication Systems and Networks, Physics Department, Shanghai Jiao Tong University, Shanghai, China.
Opt Lett. 2013 Aug 1;38(15):2846-9. doi: 10.1364/OL.38.002846.
We show that light tunneling inhibition may take place in suitable dynamically modulated waveguide arrays for light spots whose features are remarkably smaller than the wavelength of light. We found that tunneling between neighboring waveguides can be suppressed for specific frequencies of the out-of-phase refractive index modulation, affording undistorted propagation of the input subwavelength light spots over hundreds of Rayleigh lengths. Tunneling inhibition turns out to be effective only when the waveguide separation in the array is above a critical threshold. Inclusion of a weak focusing nonlinearity is shown to improve localization. We analyze the phenomenon in purely dielectric structures and also in arrays containing periodically spaced metallic layers.
我们表明，在适当的动态调制波导阵列中，光可能会发生隧道抑制，对于特征明显小于光波长的光斑点。我们发现，对于出射相位折射率调制的特定频率，相邻波导之间的隧道可以被抑制，从而使输入亚波长光斑点在数百个瑞利长度上无失真地传播。隧道抑制仅在阵列中波导的间隔大于临界阈值时才有效。我们还表明，包含弱聚焦非线性可以改善局域化。我们在纯介电结构和包含周期性间隔金属层的阵列中分析了这一现象。
