Modifying an Infrared Microscope To Characterize Propagating Surface Plasmon Polariton-Mediated Resonances

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• 作者：Marvin A. Malone ; Katherine E. Cilwa ; Matthew McCormack ; James V. Coe
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：June 30, 2011
• 年：2011
• 卷：115
• 期：25
• 页码：12250-12254
• 全文大小：817K
• 年卷期：v.115,no.25(June 30, 2011)
• ISSN：1932-7455

文摘

Metal films with periodic arrays of subwavelength holes (meshes) show extraordinary transmission resonances using ordinary, benchtop Fourier transform infrared (FTIR) spectrometers. However, the infrared study of single, wavelength-scale particles with an FTIR microscope typically involves an instrument with a large range of angles that will disperse surface plasmon polariton (SPP) resonances. This work shows how to add an aperture and mesh to a commercial FTIR microscope system to obtain well-defined and identifiable SPP transmission-mediated resonances using a dispersion geometry that is convenient to a microscope, that is, rotation of the mesh in the focal plane of the microscope about the microscope鈥檚 optical axis. Momentum matching equations are derived that identify the resonances and model the measured dispersion of each resonance. These equations effectively model the data and cover the parts of momentum space that fall between better-known, high symmetry geometric arrangements, which are often called 螕X and 螕M in the reciprocal space of a square lattice. Both a region of extensive overlapping of many resonances and a very narrow and isolated resonance were discovered that may be particularly useful for SPP studies.