I Institute of Physics (IA), RWTH Aachen University, 52056 Aachen, Germany.
Nano Lett. 2013 Aug 14;13(8):3470-5. doi: 10.1021/nl4006194. Epub 2013 Jul 2.
We show tuning of the resonance frequency of aluminum nanoantennas via variation of the refractive index n of a layer of phase-change material. Three configurations have been considered, namely, with the antennas on top of, inside, and below the layer. Phase-change materials offer a huge index change upon the structural transition from the amorphous to the crystalline state, both stable at room temperature. Since the imaginary part of their permittivity is negligibly small in the mid-infrared spectral range, resonance damping is avoided. We present resonance shifting to lower as well as to higher wavenumbers with a maximum shift of 19.3% and a tuning figure of merit, defined as the resonance shift divided by the full-width at half-maximum (FWHM) of the resonance peak, of 1.03.
我们通过改变相变材料层的折射率 n 来展示铝纳米天线的共振频率的调谐。考虑了三种配置，即天线位于层的顶部、内部和下方。相变材料在非晶态到晶态的结构转变时具有巨大的折射率变化，在室温下均稳定。由于它们的介电常数的虚部在中红外光谱范围内可忽略不计，因此避免了共振阻尼。我们展示了共振向更低和更高波数的移动，最大移动为 19.3%，调谐品质因数定义为共振移动除以共振峰的半峰全宽（FWHM）的 1.03。
