Center for Optical Technologies, Electrical and Computer Engineering Department, Lehigh University, Bethlehem, Pennsylvania 18015, USA.
Opt Lett. 2010 Dec 15;35(24):4181-3. doi: 10.1364/OL.35.004181.
We experimentally demonstrate a metal-film bidirectional surface wave splitter for guiding light at two visible wavelengths in opposite directions. Two nanoscale gratings were patterned on opposite sides of a subwavelength slit. The metallic surface grating structures were tailored geometrically to have different plasmonic bandgaps, enabling each grating to guide light of one wavelength and prohibit propagation at the other wavelength. The locations of the bandgaps were experimentally confirmed by interferometric measurements. Based on these design principles, a green-red bidirectional surface wave splitter is demonstrated, and the observed optical properties are shown to agree with theoretical predictions.
我们实验演示了一种金属薄膜双向表面波分光器，可在两个相反方向上引导可见光波长的光。两个纳米级光栅分别在亚波长狭缝的两侧形成图案。金属表面光栅结构经过精心设计，具有不同的等离子体带隙，使每个光栅只能引导一个波长的光，而阻止另一个波长的光传播。通过干涉测量实验证实了带隙的位置。基于这些设计原则，我们演示了一个红绿双向表面波分光器，观察到的光学性质与理论预测相符。
