Surface polariton in the ATR angular spectra of a thin iron film bounded by dielectric layers
Surface polariton in the ATR angular spectra of a thin iron film bounded by dielectric layers
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DOI：
10.1364/josa.68.001325
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发表时间：
1978-10
影响因子：
--
通讯作者：
G. Kovács
中科院分区：
文献类型：
--
作者：
G. Kovács
Fe的复介电常数在整个可见光区（λ i）的大部分具有大的虚部和小的真实的部|布雷尔|).在此条件下，Fe薄膜（≤ 20 nm），由电介质限制，可以支持表面极化激元。对于p偏振场，色散关系的反对称解具有平行于表面的近似真实的传播矢量。因此，这种反对称极化激元可以被光学激发。我们使用衰减全反射（ATR）配置与三个连续的层，冰晶石铁-冰晶石，蒸发到玻璃棱镜的基础上。表面极化激元在ATR角谱中被检测为窄的最小值。我们选择的频率，在该频率下，λ r = 0，然后入射的p偏振平面波产生零能量传播的Fe膜中的方向平行于该平面上的膜。在p偏振光谱中还存在其它更宽的极小值，其对应于第二电介质中局部化的大的场振荡。s偏振光谱中的最小值对应于第一电介质中局部化的振荡。此外，两种偏振的角反射率光谱包含由共振驻波图案引起的尖锐的最大值，该图案通过入射介质以及膜系统持续存在。
The complex dielectric constant of Fe has a large imaginary part and small real part throughout most of the visible region (∊i ≫ |∊r|). Under this condition a thin film of Fe(≤ 20 nm), bounded by a dielectric, can support a surface polariton. For p-polarized fields the antisymmetric solution to the dispersion relation has a nearly real propagation vector parallel to the surface. Hence this antisymmetric polariton can be excited optically. We use the attenuated total reflection (ATR) configuration with three successive layers, cryolite-Fe-cryolite, evaporated onto the base of a glass prism. The surface polariton is detected as a narrow minimum in the ATR angular spectrum. We choose the frequency at which ∊r = 0 and then an incident p-polarized plane wave yields zero energy propagation in the Fe film in the direction parallel to the plane on the film. There are also other broader minima in the p-polarized spectrum corresponding to large field oscillations localized in the second dielectric. Minima in the s-polarized spectrum correspond to oscillations localized in the first dielectric. In addition the angular reflectance spectrum of both polarizations contains sharp maxima caused by resonance standing wave patterns which persist through the incident medium as well as the film system.